Internet Engineering Task Force W. Wang Internet-Draft Zhejiang Gongshang University Intended status: Standards Track E. Haleplidis Expires: September 1, 2012 University of Patras K. Ogawa NTT Corporation C. Li Hangzhou H3C Tech. Co., Ltd. J. Halpern Ericsson February 29, 2012 ForCES Logical Function Block (LFB) Library draft-ietf-forces-lfb-lib-08 Abstract This document defines basic classes of Logical Function Blocks (LFBs) used in the Forwarding and Control Element Separation (ForCES). The basic LFB classes are defined according to ForCES FE model and ForCES protocol specifications, and are scoped to meet requirements of typical router functions and considered as the basic LFB library for ForCES. The library includes the descriptions of the LFBs and the XML definitions. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on September 1, 2012. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. Wang, et al. Expires September 1, 2012 [Page 1] Internet-Draft ForCES LFB Library February 2012 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Terminology and Conventions . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1. Scope of the Library . . . . . . . . . . . . . . . . . . 8 3.2. Overview of LFB Classes in the Library . . . . . . . . . 10 3.2.1. LFB Design Choices . . . . . . . . . . . . . . . . . 10 3.2.2. LFB Class Groupings . . . . . . . . . . . . . . . . . 10 3.2.3. Sample LFB Class Application . . . . . . . . . . . . 12 3.3. Document Structure . . . . . . . . . . . . . . . . . . . 13 4. Base Types . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.1. Data Types . . . . . . . . . . . . . . . . . . . . . . . 15 4.1.1. Atomic . . . . . . . . . . . . . . . . . . . . . . . 15 4.1.2. Compound Struct . . . . . . . . . . . . . . . . . . . 16 4.1.3. Compound Array . . . . . . . . . . . . . . . . . . . 16 4.2. Frame Types . . . . . . . . . . . . . . . . . . . . . . . 17 4.3. MetaData Types . . . . . . . . . . . . . . . . . . . . . 17 4.4. XML for Base Type Library . . . . . . . . . . . . . . . . 18 5. LFB Class Description . . . . . . . . . . . . . . . . . . . . 43 5.1. Ethernet Processing LFBs . . . . . . . . . . . . . . . . 43 5.1.1. EtherPHYCop . . . . . . . . . . . . . . . . . . . . . 44 5.1.2. EtherMACIn . . . . . . . . . . . . . . . . . . . . . 46 5.1.3. EtherClassifier . . . . . . . . . . . . . . . . . . . 47 5.1.4. EtherEncap . . . . . . . . . . . . . . . . . . . . . 50 5.1.5. EtherMACOut . . . . . . . . . . . . . . . . . . . . . 52 5.2. IP Packet Validation LFBs . . . . . . . . . . . . . . . . 53 5.2.1. IPv4Validator . . . . . . . . . . . . . . . . . . . . 53 5.2.2. IPv6Validator . . . . . . . . . . . . . . . . . . . . 55 5.3. IP Forwarding LFBs . . . . . . . . . . . . . . . . . . . 56 5.3.1. IPv4UcastLPM . . . . . . . . . . . . . . . . . . . . 57 5.3.2. IPv4NextHop . . . . . . . . . . . . . . . . . . . . . 59 5.3.3. IPv6UcastLPM . . . . . . . . . . . . . . . . . . . . 61 5.3.4. IPv6NextHop . . . . . . . . . . . . . . . . . . . . . 63 5.4. Redirect LFBs . . . . . . . . . . . . . . . . . . . . . . 65 5.4.1. RedirectIn . . . . . . . . . . . . . . . . . . . . . 65 Wang, et al. Expires September 1, 2012 [Page 2] Internet-Draft ForCES LFB Library February 2012 5.4.2. RedirectOut . . . . . . . . . . . . . . . . . . . . . 66 5.5. General Purpose LFBs . . . . . . . . . . . . . . . . . . 67 5.5.1. BasicMetadataDispatch . . . . . . . . . . . . . . . . 67 5.5.2. GenericScheduler . . . . . . . . . . . . . . . . . . 68 6. XML for LFB Library . . . . . . . . . . . . . . . . . . . . . 71 7. LFB Class Use Cases . . . . . . . . . . . . . . . . . . . . . 100 7.1. IPv4 Forwarding . . . . . . . . . . . . . . . . . . . . . 100 7.2. ARP processing . . . . . . . . . . . . . . . . . . . . . 101 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 104 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 105 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 106 10.1. LFB Class Names and LFB Class Identifiers . . . . . . . . 106 10.2. Metadata ID . . . . . . . . . . . . . . . . . . . . . . . 108 10.3. Exception ID . . . . . . . . . . . . . . . . . . . . . . 108 10.4. Validate Error ID . . . . . . . . . . . . . . . . . . . . 109 11. Security Considerations . . . . . . . . . . . . . . . . . . . 111 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 112 12.1. Normative References . . . . . . . . . . . . . . . . . . 112 12.2. Informative References . . . . . . . . . . . . . . . . . 112 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 113 Wang, et al. Expires September 1, 2012 [Page 3] Internet-Draft ForCES LFB Library February 2012 1. Terminology and Conventions 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Wang, et al. Expires September 1, 2012 [Page 4] Internet-Draft ForCES LFB Library February 2012 2. Definitions This document follows the terminology defined by the ForCES protocol in [RFC5810] and by the ForCES FE model in [RFC5812]. The definitions below are repeated for clarity. Control Element (CE) - A logical entity that implements the ForCES protocol and uses it to instruct one or more FEs on how to process packets. CEs handle functionality such as the execution of control and signaling protocols. Forwarding Element (FE) - A logical entity that implements the ForCES protocol. FEs use the underlying hardware to provide per- packet processing and handling as directed/controlled by one or more CEs via the ForCES protocol. ForCES Network Element (NE) - An entity composed of one or more CEs and one or more FEs. To entities outside an NE, the NE represents a single point of management. Similarly, an NE usually hides its internal organization from external entities. LFB (Logical Function Block) - The basic building block that is operated on by the ForCES protocol. The LFB is a well defined, logically separable functional block that resides in an FE and is controlled by the CE via ForCES protocol. The LFB may reside at the FE's datapath and process packets or may be purely an FE control or configuration entity that is operated on by the CE. Note that the LFB is a functionally accurate abstraction of the FE's processing capabilities, but not a hardware-accurate representation of the FE implementation. FE Model - The FE model is designed to model the logical processing functions of an FE, which is defined by the ForCES FE model document [RFC5812]. The FE model proposed in this document includes three components; the LFB modeling of individual Logical Functional Block (LFB model), the logical interconnection between LFBs (LFB topology), and the FE-level attributes, including FE capabilities. The FE model provides the basis to define the information elements exchanged between the CE and the FE in the ForCES protocol [RFC5810]. FE Topology - A representation of how the multiple FEs within a single NE are interconnected. Sometimes this is called inter-FE topology, to be distinguished from intra-FE topology (i.e., LFB topology). Wang, et al. Expires September 1, 2012 [Page 5] Internet-Draft ForCES LFB Library February 2012 LFB Class and LFB Instance - LFBs are categorized by LFB Classes. An LFB Instance represents an LFB Class (or Type) existence. There may be multiple instances of the same LFB Class (or Type) in an FE. An LFB Class is represented by an LFB Class ID, and an LFB Instance is represented by an LFB Instance ID. As a result, an LFB Class ID associated with an LFB Instance ID uniquely specifies an LFB existence. LFB Metadata - Metadata is used to communicate per-packet state from one LFB to another, but is not sent across the network. The FE model defines how such metadata is identified, produced and consumed by the LFBs. It defines the functionality but not how metadata is encoded within an implementation. LFB Component - Operational parameters of the LFBs that must be visible to the CEs are conceptualized in the FE model as the LFB components. The LFB components include, for example, flags, single parameter arguments, complex arguments, and tables that the CE can read and/or write via the ForCES protocol (see below). LFB Topology - Representation of how the LFB instances are logically interconnected and placed along the datapath within one FE. Sometimes it is also called intra-FE topology, to be distinguished from inter-FE topology. Data Path - A conceptual path taken by packets within the forwarding plane inside an FE. Note that more than one data path can exist within an FE. ForCES Protocol - While there may be multiple protocols used within the overall ForCES architecture, the term "ForCES protocol" and "protocol" refer to the Fp reference points in the ForCES Framework in [RFC3746]. This protocol does not apply to CE-to-CE communication, FE-to-FE communication, or to communication between FE and CE managers. Basically, the ForCES protocol works in a master-slave mode in which FEs are slaves and CEs are masters. This document defines the specifications for this ForCES protocol. LFB Port - A port refers to an LFB input port or output port. See Section 3.2 of [RFC5812] for more detailed definitions. Physical Port - A port refers to a physical media input port or output port of an FE. A physical port is usually assigned with a physical port ID, abbreviated with a PHYPortID. This document mainly deals with physical ports with Ethernet media. Wang, et al. Expires September 1, 2012 [Page 6] Internet-Draft ForCES LFB Library February 2012 Logical Port - A conceptually virtual port at data link layer (L2) or network layer (L3). A logical port is usually assigned with a logical port ID, abbreviated with a LogicalPortID. The logical ports can be further categorized with a L2 logical port or a L3 logical port. An L2 logical port can be assigned with a L2 logical port ID, abbreviated with a L2PortID. An L3 logical port can be assigned with a L3 logical port ID, abbreviated with a L3PortID. MAC layer VLAN ports belongs to L2 logical ports as well as logical ports. LFB Class Library - The LFB class library is a set of LFB classes that has been identified as the most common functions found in most FEs and hence should be defined first by the ForCES Working Group. The LFB Class Library is defined by this document. Wang, et al. Expires September 1, 2012 [Page 7] Internet-Draft ForCES LFB Library February 2012 3. Introduction [RFC5810] specifies Forwarding and Control Element Separation (ForCES) framework. In the framework, Control Elements (CEs) configure and manage one or more separate Forwarding Elements (FEs) within a Network Element (NE) by use of a ForCES protocol. [RFC5810] specifies the ForCES protocol. [RFC5812] specifies the Forwarding Element (FE) model. In the model, resources in FEs are described by classes of Logical Function Blocks (LFBs). The FE model defines the structure and abstract semantics of LFBs, and provides XML schema for the definitions of LFBs. This document conforms to the specifications of the FE model [RFC5812] and specifies detailed definitions of classes of LFBs, including detailed XML definitions of LFBs. These LFBs form a base LFB library for ForCES. LFBs in the base library are expected to be combined to form an LFB topology for a typical router to implement IP forwarding. It should be emphasized that an LFB is an abstraction of functions rather than its implementation details. The purpose of the LFB definitions is to represent functions so as to provide interoperability between separate CEs and FEs. More LFB classes with more functions may be developed in future time and documented by IETF. Vendors may also develop proprietary LFB classes as described in the FE model [RFC5812]. 3.1. Scope of the Library It is intended that the LFB classes described in this document are designed to provide the functions of a typical router. [RFC5812] specifies that a typical router is expected to provide functions to: (1) Interface to packet networks and implement the functions required by that network. These functions typically include: * Encapsulating and decapsulating the IP datagrams with the connected network framing (e.g., an Ethernet header and checksum), * Sending and receiving IP datagrams up to the maximum size supported by that network, this size is the network's Maximum Transmission Unit or MTU, * Translating the IP destination address into an appropriate network-level address for the connected network (e.g., an Ethernet hardware address), if needed, and Wang, et al. Expires September 1, 2012 [Page 8] Internet-Draft ForCES LFB Library February 2012 * Responding to network flow control and error indications, if any. (2) Conform to specific Internet protocols including the Internet Protocol (IPv4 and/or IPv6), Internet Control Message Protocol (ICMP), and others as necessary. (3) Receive and forward Internet datagrams. Important issues in this process are buffer management, congestion control, and fairness. * Recognizes error conditions and generates ICMP error and information messages as required. * Drops datagrams whose time-to-live fields have reached zero. * Fragments datagrams when necessary to fit into the MTU of the next network. (4) Choose a next hop destination for each IP datagram, based on the information in its routing database. (5) Usually support an interior gateway protocol (IGP) to carry out distributed routing and reachability algorithms with the other routers in the same autonomous system. In addition, some routers will need to support an exterior gateway protocol (EGP) to exchange topological information with other autonomous systems. For all routers, it is essential to provide ability to manage static routing items. (6) Provide network management and system support facilities, including loading, debugging, status reporting, exception reporting and control. The classical IP router utilizing the ForCES framework constitutes a CE running some controlling IGP and/or EGP function or static route setup and FEs implementing using Logical Function Blocks (LFBs) conforming to the FE model[RFC5812] specifications. The CE, in conformance to the ForCES protocol[RFC5810] and the FE model [RFC5812] specifications, instructs the LFBs on the FE how to treat received/sent packets. Packets in an IP router are received and transmitted on physical media typically referred to as "ports". Different physical port media will have different ways for encapsulating outgoing frames and decapsulating incoming frames. The different physical media will also have different attributes that influence its behavior and how frames get encapsulated or decapsulated. This document will only Wang, et al. Expires September 1, 2012 [Page 9] Internet-Draft ForCES LFB Library February 2012 deal with Ethernet physical media. Other future documents may deal with other type of media. This document will also interchangeably refer to a port to be an abstraction that constitutes a PHY and a MAC as described by the LFBs like EtherPHYCop, EtherMACIn, and EtherMACOut. IP packets emanating from port LFBs are then processed by a validation LFB before being further forwarded to the next LFB. After the validation process the packet is passed to an LFB where IP forwarding decision is made. In the IP Forwarding LFBs, a Longest Prefix Match LFB is used to look up the destination information in a packet and select a next hop index for sending the packet onward. A next hop LFB uses the next hop index metadata to apply the proper headers to the IP packets, and direct them to the proper egress. Note that in the process of IP packets processing, in this document, we are adhering to the weak-host model [RFC1122] since that is the most usable model for a packet processing Network Element. 3.2. Overview of LFB Classes in the Library It is critical to classify functional requirements into various classes of LFBs and construct a typical but also flexible enough base LFB library for various IP forwarding equipments. 3.2.1. LFB Design Choices A few design principles were factored into choosing how the base LFBs looked like. These are: o If a function can be designed by either one LFB or two or more LFBs with the same cost, the choice is to go with two or more LFBs so as to provide more flexibility for implementers. o When flexibility is not required, an LFB should take advantage of its independence as much as possible and have minimal coupling with other LFBs. The coupling may be from LFB attributes definitions as well as physical implementations. o Unless there is a clear difference in functionality, similar packet processing should not be represented as two or more different LFBs. Or else, it may add extra burden on implementation to achieve interoperability. 3.2.2. LFB Class Groupings The document defines groups of LFBs for typical router function requirements: Wang, et al. Expires September 1, 2012 [Page 10] Internet-Draft ForCES LFB Library February 2012 (1) A group of Ethernet processing LFBs are defined to abstract the packet processing for Ethernet as the port media type. As the most popular media type with rich processing features, Ethernet media processing LFBs was a natural choice. Definitions for processing of other port media type like POS or ATM may be incorporated in the library in future version of the document or in a future separate document. The following LFBs are defined for Ethernet processing: * EtherPHYCop (Section 5.1.1) * EtherMACIn (Section 5.1.2) * EtherClassifier (Section 5.1.3) * EtherEncap (Section 5.1.4) * EtherMACOut (Section 5.1.5) (2) A group of LFBs are defined for IP packet validation process. The following LFBs are defined for IP validation processing: * IPv4Validator (Section 5.2.1) * IPv6Validator (Section 5.2.2) (3) A group of LFBs are defined to abstract IP forwarding process. The following LFBs are defined for IP forwarding processing: * IPv4UcastLPM (Section 5.3.1) * IPv4NextHop (Section 5.3.2) * IPv6UcastLPM (Section 5.3.3) * IPv6NextHop (Section 5.3.4) (4) A group of LFBs are defined to abstract the process for redirect operation, i.e., data packet transmission between CE and FEs. The following LFBs are defined for redirect processing: * RedirectIn (Section 5.4.1) * RedirectOut (Section 5.4.2) Wang, et al. Expires September 1, 2012 [Page 11] Internet-Draft ForCES LFB Library February 2012 (5) A group of LFBs are defined for abstracting some general purpose packet processing. These processing processes are usually general to many processing locations in an FE LFB topology. The following LFBs are defined for redirect processing: * BasicMetadataDispatch (Section 5.5.1) * GenericScheduler (Section 5.5.2) 3.2.3. Sample LFB Class Application Although Section 7 will present use cases for LFBs defined in this document, this section shows a sample LFB class application in advance so that readers can get a quick overlook of the LFB classes with the usage. Figure 1 shows the typical LFB processing path for an IPv4 unicast forwarding case with Ethernet media interfaces. To focus on the IP forwarding function, some inputs or outputs of LFBs in the figure that are not related to the function are ignored. Section 7.1 will describe the figure in details. Wang, et al. Expires September 1, 2012 [Page 12] Internet-Draft ForCES LFB Library February 2012 +-----+ +------+ | | | | | |<---------------|Ether |<----------------------------+ | | |MACOut| | | | | | | |Ether| +------+ | |PHY | | |Cop | +---+ | |#1 | +-----+ | |----->IPv6 Packets | | | | | | | | | | |Ether| | | IPv4 Packets | | |->|MACIn|-->| |-+ +----+ | +-----+ | | | | | | |---> Multicast Packets | +-----+ +---+ | | | +-----+ +---+ | Ether +->| |------->| | | | | . Classifier| | |Unicast |IPv4 | | | | . | | |Packets |Ucast|->| |--+ | . | +----+ |LPM | | | | | +---+ | IPv4 +-----+ +---+ | | +-----+ | | | Validator IPv4 | | | | | | | NextHop| | +-----+ |Ether| | |-+ IPv4 Packets | | | |->|MACIn|-->| | | | | | | | | |----->IPv6 Packets | | |Ether| +-----+ +---+ | | |PHY | Ether +----+ | | |Cop | Classifier | | +-------+ | | |#n | +------+ | | |Ether | | | | | | | | |<--|Encap |<-+ | | | | |<------| | | | | | |<---------------|Ether | ...| | +-------+ | | | |MACOut| +---| | | | | | | | +----+ | +-----+ +------+ | BasicMetadataDispatch | +----------->-------------+ Figure 1: LFB use case for IPv4 forwarding 3.3. Document Structure Base type definitions, including data types, packet frame types, and metadata types are presented in advance for definitions of various LFB classes. Section 4 (Base Types section) provides a description on the base types used by this LFB library. To enable extensive use of these base types by other LFB class definitions, the base type definitions are provided as a separate library. Wang, et al. Expires September 1, 2012 [Page 13] Internet-Draft ForCES LFB Library February 2012 Within every group of LFB classes, a set of LFBs are defined for individual function purposes. Section 5 (LFB Class Descriptions section) provides text descriptions on the individual LFBs. Note that for a complete definition of an LFB, a text description as well as a XML definition is required. LFB classes are finally defined by XML with specifications and schema defined in the ForCES FE model[RFC5812]. Section 6 (XML LFB Definitions section) provides the complete XML definitions of the base LFB classes library. Section 7 provides several use cases on how some typical router functions can be implemented using the base LFB library defined in this document. Wang, et al. Expires September 1, 2012 [Page 14] Internet-Draft ForCES LFB Library February 2012 4. Base Types The FE model [RFC5812] has specified predefined (built-in) atomic data-types as below: char, uchar, int16, uint16, int32, uint32, int64, uint64, string[N], string, byte[N], boolean, octetstring[N], float16, float32, float64. Based on the atomic data types and with the use of type definition elements in the FE model XML schema, new data types, packet frame types, and metadata types can be defined. To define a base LFB library for typical router functions, a set of base data types, frame types, and metadata types should be defined. This section provides a brief description of the base types and a full XML definition of them as well. The base type XML definitions are provided with a separate XML library file named "BaseTypeLibrary". Users can refer to this library by the statement: 4.1. Data Types Data types defined in the base type library are categorized by types of atomic, compound struct, and compound array. 4.1.1. Atomic The following data types are defined as atomic data types and put in the base type library: Data Type Name Brief Description -------------- ----------------- IPv4Addr IPv4 address IPv6Addr IPv6 address IEEEMAC IEEE MAC address LANSpeedType LAN speed by value types DuplexType Duplex types PortStatusType The possible types of port status, used for both administrative and operative status. VlanIDType The type of VLAN ID VlanPriorityType The type of VLAN priority SchdDisciplineType Scheduling discipline type Wang, et al. Expires September 1, 2012 [Page 15] Internet-Draft ForCES LFB Library February 2012 4.1.2. Compound Struct The following compound struct types are defined in the base type library: Data Type Name Brief Description -------------- ----------------- EtherDispatchEntryType Entry type for Ethernet dispatch table VlanInputTableEntryType Entry type for VLAN input table EncapTableEntryType Entry type for Ethernet encapsulation table MACInStatsType Statistics type for EtherMACIn LFB MACOutStatsType Statistics type for EtherMACOut LFB EtherClassifyStatsType Entry type for statistics table in EtherClassifier LFB. IPv4PrefixInfoType Entry type for IPv4 prefix table IPv6PrefixInfoType Entry type for IPv6 prefix table IPv4NextHopInfoType Entry type for IPv4 next hop table IPv6NextHopInfoType Entry type for IPv6 next hop table IPv4ValidatorStatsType Statistics type in IPv4validator LFB IPv6ValidatorStatsType Statistics type in IPv6validator LFB IPv4UcastLPMStatsType Statistics type in IPv4UcastLPM LFB IPv6UcastLPMStatsType Statistics type in IPv6UcastLPM LFB QueueStatsType Entry type for queue depth table MetadataDispatchType Entry type for metadata dispatch table 4.1.3. Compound Array Compound array types are mostly created based on compound struct types for LFB table components. The following compound array types are defined in this base type library: Data Type Name Brief Description -------------- ----------------- EtherClassifyStatsTableType Type for Ethernet classifier statistics information table. EtherDispatchTableType Type for Ethernet dispatch table VlanInputTableType Type for VLAN input table EncapTableType Type for Ethernet encapsulation table IPv4PrefixTableType Type for IPv4 prefix table IPv6PrefixTableType Type for IPv6 prefix table IPv4NextHopTableType Type for IPv4 next hop table IPv6NextHopTableType Type for IPv6 next hop table MetadataDispatchTableType Type for Metadata dispatch table QueueStatsTableType Type for Queue depth table Wang, et al. Expires September 1, 2012 [Page 16] Internet-Draft ForCES LFB Library February 2012 4.2. Frame Types According to FE model [RFC5812], frame types are used in LFB definitions to define packet frame types both an LFB expects at its input port and the LFB emits at its output port. The element in the FE model is used to define a new frame type. The following frame types are defined in the base type library: Frame Name Brief Description -------------- ---------------- EthernetII An Ethernet II frame ARP An ARP packet IPv4 An IPv4 packet IPv6 An IPv6 packet IPv4Unicast An IPv4 unicast packet IPv4Multicast An IPv4 multicast packet IPv6Unicast An IPv6 unicast packet IPv6Multicast An IPv6 multicast packet Arbitrary Any type of packet frames 4.3. MetaData Types LFB Metadata is used to communicate per-packet state from one LFB to another. The element in the FE model is used to define a new metadata type. The following metadata types are currently defined in the base type library. Wang, et al. Expires September 1, 2012 [Page 17] Internet-Draft ForCES LFB Library February 2012 Metadata Name Metadata ID Brief Description ------------ ---------- ------------- PHYPortID 1 Metadata indicating a physical port ID SrcMAC 2 Metadata indicating a source MAC address DstMAC 3 Metadata indicating a destination MAC address. LogicalPortID 4 Metadata of a logical port ID EtherType 5 Metadata indicating an Ethernet type VlanID 6 Metadata of a VLAN ID VlanPriority 7 Metadata of a VLAN priority NextHopIPv4Addr 8 Metadata representing a next hop IPv4 address. NextHopIPv6Addr 9 Metadata representing a next hop IPv6 address. HopSelector 10 Metadata indicating a hop selector ExceptionID 11 Metadata indicating exception types for exceptional cases during LFB processing. ValidateErrorID 12 Metadata indicating error types when a packet passes validation process. L3PortID 13 Metadata indicating ID of an L3 logical port. RedirectIndex 14 Metadata that CE sends to RedirectIn LFB, indicating an associated packet a group output port index of the LFB. MediaEncapInfoIndex 15 A search key a packet uses to look up a table in related LFBs to select an encapsulation media. 4.4. XML for Base Type Library EthernetAll Any type of Ethernet frame EthernetII An Ethernet II frame ARP An ARP packet Wang, et al. Expires September 1, 2012 [Page 18] Internet-Draft ForCES LFB Library February 2012 IPv4 An IPv4 packet IPv6 An IPv6 packet IPv4Unicast An IPv4 unicast packet IPv4Multicast An IPv4 multicast packet IPv6Unicast An IPv6 unicast packet IPv6Multicast An IPv6 multicast packet Arbitrary Any type of packet frames IPv4Addr IPv4 address byte[4] IPv6Addr IPv6 address byte[16] IEEEMAC IEEE MAC address byte[6] LANSpeedType LAN speed by value types Wang, et al. Expires September 1, 2012 [Page 19] Internet-Draft ForCES LFB Library February 2012 uint32 LAN_SPEED_NONE Nothing is connected LAN_SPEED_10M 10M Ethernet LAN_SPEED_100M 100M Ethernet LAN_SPEED_1G 1G Ethernet LAN_SPEED_10G 10G Ethernet LAN_SPEED_AUTO LAN speed by auto negotiation DuplexType Duplex types uint32 Auto Auto negotiation HalfDuplex Half duplex FullDuplex Full duplex Wang, et al. Expires September 1, 2012 [Page 20] Internet-Draft ForCES LFB Library February 2012 PortStatusType Data types for port status, used for both administrative and operative status. uchar Disabled Port is operatively disabled Up Port is up Down Port is down MACInStatsType Data types for statistics in EtherMACIn LFB NumPacketsReceived Number of packets received uint64 NumPacketsDropped Number of packets dropped uint64 MACOutStatsType Wang, et al. Expires September 1, 2012 [Page 21] Internet-Draft ForCES LFB Library February 2012 Data types for statistics in EtherMACOut LFB NumPacketsTransmitted Number of packets transmitted uint64 NumPacketsDropped Number of packets dropped uint64 EtherDispatchEntryType Data type for entry of Ethernet dispatch table in EtherClassifier LFB. LogicalPortID Logical port ID uint32 EtherType Ethernet type as defined in Ethernet frame header uint32 LFBOutputSelectIndex Index for a packet to select a port instance in EtherClassifier LFB group output port to link to a downstream LFB. Possible downstream LFBs are IPv4Validator, IPv6Validator, RedirectOut, etc. uint32 EtherDispatchTableType Wang, et al. Expires September 1, 2012 [Page 22] Internet-Draft ForCES LFB Library February 2012 Data type for Ethernet dispatch table in EtherClassifier LFB. The table entry type is defined by EtherDispatchEntryType. EtherDispatchEntryType VlanIDType Data type for VLAN ID uint16 VlanPriorityType Data type for VLAN priority uchar VlanInputTableEntryType Data type for entry of VLAN input table in EtherClassifier LFB. IncomingPortID The incoming port ID uint32 VlanID The VLAN ID VlanIDType Reserved Wang, et al. Expires September 1, 2012 [Page 23] Internet-Draft ForCES LFB Library February 2012 Reserved for future use uint16 LogicalPortID The logical port ID uint32 VlanInputTableType Data type for VlanInputTable in EtherClassifier LFB. The entry type is defined by VlanInputTableEntryType. Each row of the table is a struct containing an Incoming Port ID, a VLAN ID and a Logical Port ID. Every input packet is assigned with a new LogicalPortID according to the packet incoming port ID and the VLAN ID. Then, the EtherDispatchTable in the LFB dispatches every Ethernet packet to different output according to the logical port ID assigned by the VlanInputTable to the packet and the Ethernet type in the Ethernet packet header. VlanInputTableEntryType EtherClassifyStatsType Data type for entry of statistics table in EtherClassifier LFB. EtherType The Ethernet type as defined in Ethernet packet header uint32 PacketsNum Packets number uint64 Wang, et al. Expires September 1, 2012 [Page 24] Internet-Draft ForCES LFB Library February 2012 EtherClassifyStatsTableType Data type for Ethernet classifying statistics table in EtherClassifier LFB, the entry of which is defined by EtherClassifyStatsType. EtherClassifyStatsType IPv4ValidatorStatsType Data type for statistics in IPv4validator LFB badHeaderPkts Number of bad header packets uint64 badTotalLengthPkts Number of packets with bad total length uint64 badTTLPkts Number of bad TTL packets uint64 badChecksumPkts Number of bad checksum packets uint64 IPv6ValidatorStatsType Data type for statistics in IPv6validator LFB Wang, et al. Expires September 1, 2012 [Page 25] Internet-Draft ForCES LFB Library February 2012 badHeaderPkts Number of bad header packets uint64 badTotalLengthPkts Number of bad total length packets uint64 badHopLimitPkts Number of bad hop limit packets uint64 IPv4PrefixInfoType Data type for entry of IPv4 prefix table IPv4Address The IPv4 address IPv4Addr Prefixlen The prefix length uchar ECMPFlag ECMP flag boolean False ECMP flag is false, indicating the route does not have multiple next hops. Wang, et al. Expires September 1, 2012 [Page 26] Internet-Draft ForCES LFB Library February 2012 True ECMP flag is true, indicating the route has multiple next hops. DefaultRouteFlag Default route flag boolean False Default route flag is false, indicating the route is not a default route. True Default route flag is true, indicating the route is a default route. Reserved Reserved for future use uchar HopSelector HopSelector is produced by the prefix match LFB and output to downstream LFBs as a next hop information identifier. uint32 Wang, et al. Expires September 1, 2012 [Page 27] Internet-Draft ForCES LFB Library February 2012 IPv4PrefixTableType Data type for IPv4 longest prefix match table used for IPv4UcastLPM LFB. The destination IPv4 address of every input packet is used as a search key to look up the table to find out a next hop selector. Entry type of the table is defined by IPv4PrefixInfoType. IPv4PrefixInfoType IPv4UcastLPMStatsType Statistics type in IPv4UcastLPM LFB InRcvdPkts Total number of input packets received uint64 FwdPkts Packets forwarded by the LFB uint64 NoRoutePkts Packets with no routes found uint64 IPv6PrefixInfoType Entry type for IPv6 prefix table IPv6Address The IPv6 address IPv6Addr Wang, et al. Expires September 1, 2012 [Page 28] Internet-Draft ForCES LFB Library February 2012 Prefixlen The prefix length uchar ECMPFlag ECMP flag boolean False ECMP flag is false, indicating the route does not have multiple next hops. True ECMP flag is true, indicating the route has multiple next hops. DefaultRouteFlag Default route flag boolean False Default route flag is false, indicating the route is not a default route. True Wang, et al. Expires September 1, 2012 [Page 29] Internet-Draft ForCES LFB Library February 2012 Default route flag is true, indicating the route is a default route. Reserved Reserved for future use uchar HopSelector HopSelector is produced by the prefix match LFB and output to downstream LFBs as a next hop information identifier. uint32 IPv6PrefixTableType Data type for IPv6 longest prefix match table used for IPv6UcastLPM LFB. The destination IPv6 address of every input packet is used as a search key to look up the table to find out a next hop selector. Entry type of the table is defined by IPv6PrefixInfoType. IPv6PrefixInfoType IPv6UcastLPMStatsType Statistics type in IPv6UcastLPM LFB InRcvdPkts Total number of input packets received uint64 Wang, et al. Expires September 1, 2012 [Page 30] Internet-Draft ForCES LFB Library February 2012 FwdPkts Packets forwarded by the LFB uint64 NoRoutePkts Packets with no routes found uint64 IPv4NextHopInfoType Data type for entry of IPv4 next hop information table used in IPv4NextHop LFB. L3PortID The L3PortID is the ID of the logical output port that is passed onto the downstream LFB, indicating what port to the neighbor is as defined by L3. uint32 MTU Maximum Transmission Unit for outgoing port uint32 NextHopIPAddr Next hop IPv4 address IPv4Addr MediaEncapInfoIndex The index is passed onto the downstream encapsulation LFB instance and is used there as a search key to lookup the index of a table (typically media encapsulation related) for further encapsulation information. Wang, et al. Expires September 1, 2012 [Page 31] Internet-Draft ForCES LFB Library February 2012 uint32 LFBOutputSelectIndex The index is for the LFB Group output port to select downstream LFB port. It is a 1-to-1 mapping with FEObject LFB's table LFBTopology component FromPortIndex corresponding to the port group mapping FromLFBID as IPv4NextHop LFB instance. uint32 IPv4NextHopTableType Data type for IPv4 next hop table in IPv4NextHop LFB. The LFB uses a hop selector metadata received from upstream LFB as a search key to look up the index of the table to get next hop information. Entry type of the table is defined by IPv4NextHopInfoType. IPv4NextHopInfoType IPv6NextHopInfoType Data type for entry of IPv6 next hop information table used in IPv6NextHop LFB. L3PortID The L3PortID is the ID of the logical output port that is passed onto the downstream LFB, indicating what port to the neighbor is as defined by L3. uint32 MTU Wang, et al. Expires September 1, 2012 [Page 32] Internet-Draft ForCES LFB Library February 2012 Maximum Transmission Unit for outgoing port uint32 NextHopIPAddr Next hop IPv6 address IPv6Addr MediaEncapInfoIndex The index is passed onto the downstream encapsulation LFB instance and is used there as a search key to lookup the index of a table (typically media encapsulation related) for further encapsulation information. uint32 LFBOutputSelectIndex The index is for the LFB group output port to select downstream LFB port. It is a 1-to-1 mapping with FEObject LFB's table LFBTopology component FromPortIndex corresponding to the port group mapping FromLFBID as IPv6NextHop LFB instance. uint32 IPv6NextHopTableType Data type for IPv6 next hop table in IPv6NextHop LFB. The LFB uses a hop selector metadata received from upstream LFB as a search key to look up the index of the table to get next hop information. Entry type of the table is defined by IPv6NextHopInfoType. IPv6NextHopInfoType EncapTableEntryType Wang, et al. Expires September 1, 2012 [Page 33] Internet-Draft ForCES LFB Library February 2012 Data type for entry of Ethernet encapsulation table in EtherEncap LFB. DstMac Destination MAC address for Ethernet encapsulation of the packet. IEEEMAC SrcMac Source MAC address for Ethernet encapsulation of the packet. IEEEMAC VlanID The VLAN ID assigned to the packet VlanIDType Reserved Reserved for future use uint16 L2PortID The L2 logical output port ID for the packet uint32 EncapTableType Data type for Ethernet encapsulation table in Etherencap LFB. The LFB uses the metadata "MediaEncapInfoIndex" received from upstream LFB as the index of the table to get encapsulation information of every packet.Entry type of the table is defined by EncapTableEntryType. Wang, et al. Expires September 1, 2012 [Page 34] Internet-Draft ForCES LFB Library February 2012 EncapTableEntryType MetadataDispatchType Data type for entry of metadata dispatch table used in BasicMetadataDispatch LFB. MetadataValue The value of the dispatch metadata uint32 OutputIndex Index of a group output port for outgoing packets with the dispatch metadata value. uint32 MetadataDispatchTableType Data type for metadata dispatch table used in BasicMetadataDispatch LFB. The LFB uses a metadata value as the search key to look up the table to get an index of the LFB group output port for output of the packet. Metadata value of the table is also defined as a content key field so that CE can manipulate the table by means of a content key. MetadataDispatchType MetadataValue SchdDisciplineType Scheduling discipline types Wang, et al. Expires September 1, 2012 [Page 35] Internet-Draft ForCES LFB Library February 2012 uint32 RR Round Robin scheduling discipline QueueStatsType Data type for entry of queue statistics table in GenericScheduler LFB. QueueID The input queue ID uint32 QueueDepthInPackets Current queue depth in packets uint32 QueueDepthInBytes Current queue depth in bytes uint32 QueueStatsTableType Data type for queue statistics table in GenericScheduler LFB. Entry type of the table is defined by QueueStatsType. QueueStatsType Wang, et al. Expires September 1, 2012 [Page 36] Internet-Draft ForCES LFB Library February 2012 PHYPortID Metadata indicating a physical port ID 1 uint32 SrcMAC Metadata indicating a source MAC address 2 IEEEMAC DstMAC Metadata indicating a destination MAC address 3 IEEEMAC LogicalPortID Metadata of a logical port ID 4 uint32 EtherType Metadata indicating an Ethernet type 5 uint32 VlanID Metadata of a VLAN ID 6 VlanIDType VlanPriority Metadata of a VLAN priority 7 VlanPriorityType NextHopIPv4Addr Metadata representing a next hop IPv4 address Wang, et al. Expires September 1, 2012 [Page 37] Internet-Draft ForCES LFB Library February 2012 8 IPv4Addr NextHopIPv6Addr Metadata representing a next hop IPv6 address 9 IPv6Addr HopSelector Metadata indicating a hop selector 10 uint32 ExceptionID Metadata indicating exception types for exceptional cases during LFB processing. 11 uint32 AnyUnrecognizedExceptionCase Any unrecognized exception case ClassifyNoMatching There is no matching of tables in EtherClassifier LFB. MediaEncapInfoIndexInvalid The MediaEncapInfoIndex value of the packet is invalid and cannot be allocated in the EncapTable in EtherEncap LFB. EncapTableLookupFailed Wang, et al. Expires September 1, 2012 [Page 38] Internet-Draft ForCES LFB Library February 2012 The packet failed lookup of the EncapTable table in EtherEncap LFB even though the MediaEncapInfoIndex is valid. BadTTL Packet with expired TTL IPv4HeaderLengthMismatch Packet with header length more than 5 words RouterAlertOptions Packet IP head includes router alert Options IPv6HopLimitZero Packet with the hop limit zero IPv6NextHeaderHBH Packet with next header set to Hop-by-Hop SrcAddressExecption Packet with exceptional source address DstAddressExecption Packet with exceptional destination address LPMLookupFailed Packet failed the LPM table lookup in a prefix Wang, et al. Expires September 1, 2012 [Page 39] Internet-Draft ForCES LFB Library February 2012 match LFB. HopSelectorInvalid HopSelector for the packet is invalid NextHopLookupFailed Packet failed lookup of a next hop table even though HopSelector is valid. FragRequired Packet fragmentation is required MetadataNoMatching There is no matching when looking up the metadata dispatch table in BasicMetadataDispatch LFB. ValidateErrorID Metadata indicating error types when a packet passes validation process. 12 uint32 AnyUnrecognizedValidateErrorCase Any unrecognized validate error case Wang, et al. Expires September 1, 2012 [Page 40] Internet-Draft ForCES LFB Library February 2012 InvalidIPv4PacketSize Packet length reported by the link layer is less than 20 bytes. NotIPv4Packet Packet is not IP version 4 InvalidIPv4HeaderLengthSize Packet with header length field in the header less than 5 words. InvalidIPv4LengthFieldSize Packet with total length field in the header less than 20 bytes. InvalidIPv4Checksum Packet with invalid checksum InvalidIPv4SrcAddr Packet with invalid IPv4 source address InvalidIPv4DstAddr Packet with invalid IPv4 destination address InvalidIPv6PacketSize Packet size is less than 40 bytes Wang, et al. Expires September 1, 2012 [Page 41] Internet-Draft ForCES LFB Library February 2012 NotIPv6Packet Packet is not IP version 6 InvalidIPv6SrcAddr Packet with invalid IPv6 source address InvalidIPv6DstAddr Packet with invalid IPv6 destination address L3PortID Metadata indicating ID of an L3 logical port 13 uint32 RedirectIndex Metadata that CE sends to RedirectIn LFB, indicating an associated packet a group output port index of the LFB. 14 uint32 MediaEncapInfoIndex A search key a packet uses to look up a table in related LFBs to select an encapsulation media. 15 uint32 Wang, et al. Expires September 1, 2012 [Page 42] Internet-Draft ForCES LFB Library February 2012 5. LFB Class Description According to ForCES specifications, LFB (Logical Function Block) is a well defined, logically separable functional block that resides in an FE, and is a functionally accurate abstraction of the FE's processing capabilities. An LFB Class (or type) is a template that represents a fine-grained, logically separable aspect of FE processing. Most LFBs are related to packet processing in the data path. LFB classes are the basic building blocks of the FE model. Note that [RFC5810] has already defined an 'FE Protocol LFB' which is a logical entity in each FE to control the ForCES protocol. [RFC5812] has already defined an 'FE Object LFB'. Information like the FE Name, FE ID, FE State, LFB Topology in the FE are represented in this LFB. As specified in Section 3.1, this document focuses on the base LFB library for implementing typical router functions, especially for IP forwarding functions. As a result, LFB classes in the library are all base LFBs to implement router forwarding. In this section, the terms "upstream LFB" and "downstream LFB" are used. These are used relative to an LFB to an LFB that is being described. An "upstream LFB" is one whose output ports are connected to input ports of the LFB under consideration such that output (typically packets with metadata) can be sent from the "upstream LFB" to the LFB under consideration. Similarly, a "downstream LFB" whose input ports are connected to output ports of the LFB under consideration such that the LFB under consideration can send information to the "downstream LFB". Note that in some rare topologies, an LFB may be both upstream and downstream relative to another LFB. Also note that, as a default provision of [RFC5812], in FE model, all metadata produced by upstream LFBs will pass through all downstream LFBs by default without being specified by input port or output port. Only those metadata that will be used (consumed) by an LFB will be explicitly marked in input of the LFB as expected metadata. For instance, in downstream LFBs of a physical layer LFB, even there is no specific metadata expected, metadata like PHYPortID produced by the physical layer LFB will always pass through all downstream LFBs regardless of whether the metadata has been expected by the LFBs or not. 5.1. Ethernet Processing LFBs As the most popular physical and data link layer protocols, Ethernet is widely deployed. It becomes a basic requirement for a router to be able to process various Ethernet data packets. Wang, et al. Expires September 1, 2012 [Page 43] Internet-Draft ForCES LFB Library February 2012 Note that there exist different versions of Ethernet formats, like Ethernet V2, 802.3 RAW, IEEE 802.3/802.2, IEEE 802.3/802.2 SNAP. There also exist varieties of LAN techniques based on Ethernet, like various VLANs, MACinMAC, etc. Ethernet processing LFBs defined here are intended to be able to cope with all these variations of Ethernet technology. There are also various types of Ethernet physical interface media. Among them, copper and fiber media may be the most popular ones. As a base LFB definition and a starting point, the document only defines an Ethernet physical LFB with copper media. For other media interfaces, specific LFBs may be defined in the future versions of the library. 5.1.1. EtherPHYCop EtherPHYCop LFB abstracts an Ethernet interface physical layer with media limited to copper. 5.1.1.1. Data Handling This LFB is the interface to the Ethernet physical media. The LFB handles Ethernet frames coming in from or going out of the FE. Ethernet frames sent and received cover all packets encapsulated with different versions of Ethernet protocols, like Ethernet V2, 802.3 RAW, IEEE 802.3/802.2,IEEE 802.3/802.2 SNAP, including packets encapsulated with varieties of LAN techniques based on Ethernet, like various VLANs, MACinMAC, etc. Therefore in the XML an EthernetAll frame type has been introduced. Ethernet frames are received from the physical media port and passed downstream to LFBs such as EtherMACIn via a singleton output known as "EtherPHYOut". A 'PHYPortID' metadata, to indicate which physical port the frame came into from the external world, is passed along with the frame. Ethernet packets are received by this LFB from upstream LFBs such as EtherMacOut LFBs via the singleton input known as "EtherPHYIn" before being sent out onto the external world. 5.1.1.2. Components The AdminStatus component is defined for CE to administratively manage the status of the LFB. The CE may administratively startup or shutdown the LFB by changing the value of AdminStatus. The default value is set to 'Down'. An OperStatus component captures the physical port operational Wang, et al. Expires September 1, 2012 [Page 44] Internet-Draft ForCES LFB Library February 2012 status. A PHYPortStatusChanged event is defined so the LFB can report to the CE whenever there is an operational status change of the physical port. The PHYPortID component is a unique identification for a physical port. It is defined as 'read-only' by CE. Its value is enumerated by FE. The component will be used to produce a 'PHYPortID' metadata at the LFB output and to associate it to every Ethernet packet this LFB receives. The metadata will be handed to downstream LFBs for them to use the PHYPortID. A group of components are defined for link speed management. The AdminLinkSpeed is for CE to configure link speed for the port and the OperLinkSpeed is for CE to query the actual link speed in operation. The default value for the AdminLinkSpeed is set to auto-negotiation mode. A group of components are defined for duplex mode management. The AdminDuplexMode is for CE to configure proper duplex mode for the port and the OperDuplexMode is for CE to query the actual duplex mode in operation. The default value for the AdminDuplexMode is set to auto-negotiation mode. A CarrierStatus component captures the status of the carrier and specifies whether the port link is operationally up. The default value for the CarrierStatus is 'false'. 5.1.1.3. Capabilities The capability information for this LFB includes the link speeds that are supported by the FE (SupportedLinkSpeed) as well as the supported duplex modes (SupportedDuplexMode). 5.1.1.4. Events Several events are generated. There is an event for changes in the status of the physical port (PhyPortStatusChanged). Such an event will notify that the physical port status has been changed and the report will include the new status of the physical port. Another event captures changes in the operational link speed (LinkSpeedChanged). Such an event will notify the CE that the operational speed has been changed and the report will include the new negotiated operational speed. A final event captures changes in the duplex mode (DuplexModeChanged). Such an event will notify the CE that the duplex mode has been changed and the report will include the new Wang, et al. Expires September 1, 2012 [Page 45] Internet-Draft ForCES LFB Library February 2012 negotiated duplex mode. 5.1.2. EtherMACIn EtherMACIn LFB abstracts an Ethernet port at MAC data link layer. This LFB describes Ethernet processing functions like MAC address locality check, deciding if the Ethernet packets should be bridged, providing Ethernet layer flow control, etc. 5.1.2.1. Data Handling The LFB is expected to receive all types of Ethernet packets, via a singleton input known as "EtherPktsIn", which are usually output from some Ethernet physical layer LFB, like an EtherPHYCop LFB, alongside with a metadata indicating the physical port ID that the packet arrived on. The LFB is defined with two separate singleton outputs. All Output packets are emitted in the original Ethernet format received at the physical port, unchanged, and cover all types of Ethernet types. The first singleton output is known as "NormalPathOut". It usually outputs Ethernet packets to some LFB like an EtherClassifier LFB for further L3 forwarding process alongside with a PHYPortID metadata indicating which physical port the packet came from. The second singleton output is known as "L2BridgingPathOut". Although the LFB library this document defines is basically to meet typical router functions, it will attempt to be forward compatible with future router functions. The "L2BridgingPathOut" is defined to meet the requirement that L2 bridging functions may be optionally supported simultaneously with L3 processing and some L2 bridging LFBs that may be defined in the future. If the FE supports L2 bridging, the CE can enable or disable it by means of a "L2BridgingPathEnable" component in the FE. If it is enabled, by also instantiating some L2 bridging LFB instances following the L2BridgingPathOut, FEs are expected to fulfill L2 bridging functions. L2BridgingPathOut will output packets exactly the same as that in the NormalPathOut output. This LFB can be set to work in a Promiscuous Mode, allowing all packets to pass through the LFB without being dropped. Otherwise, a locality check will be performed based on the local MAC addresses. All packets that do not pass through the locality check will be dropped. This LFB participates in Ethernet flow control in cooperation with EtherMACOut LFB. This document does not go into the details of how this is implemented; the reader may refer to some relevant Wang, et al. Expires September 1, 2012 [Page 46] Internet-Draft ForCES LFB Library February 2012 references. This document also does not describe how the buffers which induce the flow control messages behave - it is assumed that such artifacts exist and describing them is out of scope in this document. 5.1.2.2. Components The AdminStatus component is defined for the CE to administratively manage the status of the LFB. The CE may administratively startup or shutdown the LFB by changing the value of AdminStatus. The default value is set to 'Down'. The LocalMACAddresses component specifies the local MAC addresses based on which locality checks will be made. This component is an array of MAC addresses, and of 'read-write' access permission. An L2BridgingPathEnable component captures whether the LFB is set to work as a L2 bridge. An FE that does not support bridging will internally set this flag to false, and additionally set the flag property as read-only. The default value for is 'false'. The PromiscuousMode component specifies whether the LFB is set to work as in a promiscuous mode. The default value for is 'false'. The TxFlowControl component defines whether the LFB is performing flow control on sending packets. The default value for is 'false'. The RxFlowControl component defines whether the LFB is performing flow control on receiving packets. The default value for is 'false'. A struct component, MACInStats, defines a set of statistics for this LFB, including the number of received packets and the number of dropped packets. 5.1.2.3. Capabilities This LFB does not have a list of capabilities. 5.1.2.4. Events This LFB does not have any events specified. 5.1.3. EtherClassifier EtherClassifier LFB abstracts the process to decapsulate Ethernet packets and then classify them. Wang, et al. Expires September 1, 2012 [Page 47] Internet-Draft ForCES LFB Library February 2012 5.1.3.1. Data Handling This LFB describes the process of decapsulating Ethernet packets and classifying them into various network layer data packets according to information included in the Ethernet packets headers. The LFB is expected to receive all types of Ethernet packets, via a singleton input known as "EtherPktsIn", which are usually output from an upstream LFB like EtherMACIn LFB. This input is also capable of multiplexing to allow for multiple upstream LFBs being connected. For instance, when L2 bridging function is enabled in EtherMACIn LFB, some L2 bridging LFBs may be applied. In this case, some Ethernet packets after L2 processing may have to be input to EtherClassifier LFB for classification, while simultaneously packets directly output from EtherMACIn may also need to input to this LFB. This input is capable of handling such a case. Usually, all expected Ethernet Packets will be associated with a PHYPortID metadata, indicating the physical port the packet comes from. In some cases, for instance, like in a MACinMAC case, a LogicalPortID metadata may be expected to associate with the Ethernet packet to further indicate which logical port the Ethernet packet belongs to. Note that PHYPortID metadata is always expected while LogicalPortID metadata is optionally expected. Two output LFB ports are defined. The first output is a group output port known as "ClassifyOut". Types of network layer protocol packets are output to instances of the port group. Because there may be various type of protocol packets at the output ports, the produced output frame is defined as arbitrary for the purpose of wide extensibility in the future. Metadata to be carried along with the packet data is produced at this LFB for consumption by downstream LFBs. The metadata passed downstream includes PHYPortID, as well as information on Ethernet type, source MAC address, destination MAC address and the logical port ID. If the original packet is a VLAN packet and contains a VLAN ID and a VLAN priority value, then the VLAN ID and the VLAN priority value are also carried downstream as metadata. As a result, the VLAN ID and priority metadata are defined with the availability of "conditional". The second output is a singleton output port known as "ExceptionOut", which will output packets for which the data processing failed, along with an additional ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: o There is no matching when classifying the packet. Usually the exception out port may point to no where, indicating Wang, et al. Expires September 1, 2012 [Page 48] Internet-Draft ForCES LFB Library February 2012 packets with exceptions are dropped, while in some cases, the output may be pointed to the path to the CE for further processing, depending on individual implementations. 5.1.3.2. Components An EtherDispatchTable array component is defined in the LFB to dispatch every Ethernet packet to the output group according to the logical port ID assigned by the VlanInputTable to the packet and the Ethernet type in the Ethernet packet header. Each row of the array is a struct containing a Logical Port ID, an EtherType and an Output Index. With the CE configuring the dispatch table, the LFB can be expected to classify various network layer protocol type packets and output them at different output ports. It is expected that the LFB classify packets according to protocols like IPv4, IPv6, MPLS, ARP, ND, etc. A VlanInputTable array component is defined in the LFB to classify VLAN Ethernet packets. Each row of the array is a struct containing an Incoming Port ID, a VLAN ID and a Logical Port ID. According to IEEE VLAN specifications, all Ethernet packets can be recognized as VLAN types by defining that if there is no VLAN encapsulation in a packet, a case with VLAN tag 0 is considered. Every input packet is assigned with a new LogicalPortID according to the packet incoming port ID and the VLAN ID. A packet incoming port ID is defined as a logical port ID if a logical port ID is associated with the packet, or a physical port ID if no logical port ID associated. The VLAN ID is exactly the VLAN ID in the packet if it is a VLAN packet, or 0 if it is not. Note that a logical port ID of a packet may be rewritten with a new one by the VlanInputTable processing. Note that the logical port ID and physical port ID mentioned above are all originally configured by CE, and are globally effective within a ForCES NE (Network Element). To distinguish a physical port ID from a logical port ID in the incoming port ID field of the VlanInputTable, physical port ID and logical port ID must be assigned with separate number spaces. An array component, EtherClassifyStats, defines a set of statistics for this LFB, measuring the number of packets per EtherType. Each row of the array is a struct containing an EtherType and a Packet number. 5.1.3.3. Capabilities This LFB does not have a list of capabilities. Wang, et al. Expires September 1, 2012 [Page 49] Internet-Draft ForCES LFB Library February 2012 5.1.3.4. Events This LFB has no events specified. 5.1.4. EtherEncap The EtherEncap LFB abstracts the process to replace or attach appropriate Ethernet headers to the packet. 5.1.4.1. Data Handling This LFB abstracts the process of encapsulating Ethernet headers onto received packets. The encapsulation is based on passed metadata. The LFB is expected to receive IPv4 and IPv6 packets, via a singleton input port known as "EncapIn" which may be connected to an upstream LFB like an IPv4NextHop, an IPv6NextHop, BasicMetadataDispatch, or any LFB which requires to output packets for Ethernet encapsulation. The LFB always expects from upstream LFBs the MedTableiaEncapInfoIndex metadata which is used as a search key to lookup the encapsulation table EncapTable by the search key matching the table index. An input packet may also optionally receive a VLAN priority metadata, indicating that the packet is originally with a priority value. The priority value will be loaded back to the packet when encapsulating. The optional VLAN priority metadata is defined with a default value 0. Two singleton output LFB ports are defined. The first singleton output known as "SuccessOut". Upon a successful table lookup, the destination and source MAC addresses, and the logical media port (L2PortID) are found in the matching table entry. The CE may set the VlanID in case VLANs are used. By default the table entry for VlanID of 0 is used as per IEEE rules. Whatever the value of VlanID is, if the input metadata VlanPriority is non-zero, the packet will have a VLAN tag. If the VlanPriority and the VlanID are all zero, there is no VLAN tag to this packet. After replacing or attaching the appropriate Ethernet headers to the packet is complete, the packet is passed out on the "SuccessOut" LFB port to a downstream LFB instance alongside with the L2PortID. The second singleton output known as "ExceptionOut", which will output packets for which the table lookup fails, along with an additional ExceptionID metadata. Currently defined exception types only include the following case: Wang, et al. Expires September 1, 2012 [Page 50] Internet-Draft ForCES LFB Library February 2012 o The MediaEncapInfoIndex value of the packet is invalid and can not be allocated in the EncapTable. o The packet failed lookup of the EncapTable table even though the MediaEncapInfoIndex is valid. The upstream LFB may be programmed by the CE to pass along a MediaEncapInfoIndex that does not exist in the EncapTable. That is to allow for resolution of the L2 headers, if needed, to be made at the L2 encapsulation level in this case (Ethernet) via ARP, or ND (or other methods depending on the link layer technology) when a table miss occurs. For neighbor L2 header resolution(table miss exception), the processing LFB may pass this packet to the CE via the redirect LFB or FE software or another LFB instance for further resolution. In such a case the metadata NextHopIPv4Addr or NextHopIPv6Addr generated by next hop LFB is also passed to the exception handling. Such an IP address could be used to do activities such as ARP or ND by the handler it is passed to. The result of the L2 resolution is to update the EncapTable as well as the next hop LFB so subsequent packets do not fail EncapTable lookup. The EtherEncap LFB does not make any assumptions of how the EncapTable is updated by the CE (or whether ARP/ND is used dynamically or static maps exist). Downstream LFB instances could be either an EtherMACOut type or a BasicMetadataDispatch type. If the final packet L2 processing is possible to be on per-media-port basis or resides on a different FE or in cases where L2 header resolution is needed, then the model makes sense to use a BasicMetadataDispatch LFB to fan out to different LFB instances. If there is a direct egress port point, then the model makes sense to have a downstream LFB instance being an EtherMACOut. 5.1.4.2. Components This LFB has only one component named EncapTable which is defined as an array. Each row of the array is a struct containing the destination MAC address, the source MAC address, the VLAN ID with a default value of zero and the output logical L2 port ID. 5.1.4.3. Capabilities This LFB does not have a list of capabilities. Wang, et al. Expires September 1, 2012 [Page 51] Internet-Draft ForCES LFB Library February 2012 5.1.4.4. Events This LFB does not have any events specified. 5.1.5. EtherMACOut EtherMACOut LFB abstracts an Ethernet port at MAC data link layer. This LFB describes Ethernet packet output process. Ethernet output functions are closely related to Ethernet input functions, therefore many components defined in this LFB are as aliases of EtherMACIn LFB components. 5.1.5.1. Data Handling The LFB is expected to receive all types of Ethernet packets, via a singleton input known as "EtherPktsIn", which are usually output from an Ethernet encapsulation LFB, alongside with a metadata indicating the physical port ID that the packet will go through. The LFB is defined with a singleton output. All Output packets are in Ethernet format, possibly with various Ethernet types, alongside with a metadata indicating the physical port ID the packet is to go through. This output links to a downstream LFB that is usually an Ethernet physical LFB like EtherPHYcop LFB. This LFB participates in Ethernet flow control in cooperation with EtherMACIn LFB. This document does not go into the details of how this is implemented; the reader may refer to some relevant references. This document also does not describe how the buffers which induce the flow control messages behave - it is assumed that such artifacts exist and describing them is out of scope in this document. Note that as a base definition, functions like multiple virtual MAC layers are not supported in this LFB version. It may be supported in the future by defining a subclass or a new version of this LFB. 5.1.5.2. Components The AdminStatus component is defined for CE to administratively manage the status of the LFB. The CE may administratively startup or shutdown the LFB by changing the value of AdminStatus. The default value is set to 'Down'. Note that this component is defined as an alias of the AdminStatus component in the EtherMACIn LFB. This infers that an EtherMACOut LFB usually coexists with an EtherMACIn LFB, both of which share the same administrative status management by CE. Alias properties as defined in the ForCES FE model [RFC5812] will be used by CE to declare the target component this alias refers, Wang, et al. Expires September 1, 2012 [Page 52] Internet-Draft ForCES LFB Library February 2012 which include the target LFB class and instance IDs as well as the path to the target component. The MTU component defines the maximum transmission unit. The TxFlowControl component defines whether the LFB is performing flow control on sending packets. The default value for is 'false'. Note that this component is defined as an alias of TxFlowControl component in the EtherMACIn LFB. The RxFlowControl component defines whether the LFB is performing flow control on receiving packets. The default value for is 'false'. Note that this component is defined as an alias of RxFlowControl component in the EtherMACIn LFB. A struct component, MACOutStats, defines a set of statistics for this LFB, including the number of transmitted packets and the number of dropped packets. 5.1.5.3. Capabilities This LFB does not have a list of capabilities. 5.1.5.4. Events This LFB does not have any events specified. 5.2. IP Packet Validation LFBs The LFBs are defined to abstract IP packet validation process. An IPv4Validator LFB is specifically for IPv4 protocol validation and an IPv6Validator LFB for IPv6. 5.2.1. IPv4Validator The IPv4Validator LFB performs IPv4 packets validation according to [RFC5812]. 5.2.1.1. Data Handling This LFB performs IPv4 validation according to [RFC5812]. The IPv4 packet will be output to the corresponding LFB port the indication whether the packet is unicast, multicast or whether an exception has occurred or the validation failed. This LFB always expects, as input, packets which have been indicated as IPv4 packets by an upstream LFB, like an EtherClassifier LFB. There is no specific metadata expected by the input of the LFB. Wang, et al. Expires September 1, 2012 [Page 53] Internet-Draft ForCES LFB Library February 2012 Four output LFB ports are defined. All validated IPv4 unicast packets will be output at the singleton port known as "IPv4UnicastOut". All validated IPv4 multicast packets will be output at the singleton port known as "IPv4MulticastOut" port. A singleton port known as "ExceptionOut" is defined to output packets which have been validated as exception packets. An exception ID metadata is produced to indicate what has caused the exception. An exception case is the case when a packet needs further processing before being normally forwarded. Currently defined exception types include: o Packet with expired TTL o Packet with header length more than 5 words o Packet IP head including Router Alert options o Packet with exceptional source address o Packet with exceptional destination address Note that although TTL is checked in this LFB for validity, operations like TTL decrement are made by the downstream forwarding LFB. The final singleton port known as "FailOut" is defined for all packets which have errors and failed the validation process. An error case is the case when a packet is unable to be further processed nor forwarded except being dropped. An error ID is associated a packet to indicate the failure reason. Currently defined failure reasons include: o Packet with size reported less than 20 bytes o Packet with version is not IPv4 o Packet with header length less than 5 words o Packet with total length field less than 20 bytes o Packet with invalid checksum o Packet with invalid source address Wang, et al. Expires September 1, 2012 [Page 54] Internet-Draft ForCES LFB Library February 2012 o Packet with invalid destination address 5.2.1.2. Components This LFB has only one struct component, the IPv4ValidatorStatisticsType, which defines a set of statistics for validation process, including the number of bad header packets, the number of bad total length packets, the number of bad TTL packets, and the number of bad checksum packets. 5.2.1.3. Capabilities This LFB does not have a list of capabilities 5.2.1.4. Events This LFB does not have any events specified. 5.2.2. IPv6Validator The IPv6Validator LFB performs IPv6 packets validation according to [RFC2460]. 5.2.2.1. Data Handling This LFB performs IPv6 validation according to [RFC2460]. Then the IPv6 packet will be output to the corresponding port regarding of the validation result, whether the packet is a unicast or a multicast one, an exception has occurred or the validation failed. This LFB always expects, as input, packets which have been indicated as IPv6 packets by an upstream LFB, like an EtherClassifier LFB. There is no specific metadata expected by the input of the LFB. Similar to the IPv4validator LFB, IPv6Validator LFB has also defined four output ports to emit packets with various validation results. All validated IPv6 unicast packets will be output at the singleton port known as "IPv6UnicastOut". All validated IPv6 multicast packets will be output at the singleton port known as "IPv6MulticastOut" port. There is no metadata produced at this LFB. A singleton port known as "ExceptionOut" is defined to output packets which have been validated as exception packets. An exception case is the case when a packet needs further processing before being normally forwarded. An exception ID metadata is produced to indicate what caused the exception. Currently defined exception types include: Wang, et al. Expires September 1, 2012 [Page 55] Internet-Draft ForCES LFB Library February 2012 o Packet with hop limit to zero o Packet with next header set to Hop-by-Hop o Packet with exceptional source address o Packet with exceptional destination address The final singleton port known as "FailOut" is defined for all packets which have errors and failed the validation process. An error case is the case when a packet is unable to be further processed nor forwarded except being dropped. A validate error ID is associated to every failed packet to indicate the reason. Currently defined reasons include: o Packet with size reported less than 40 bytes o Packet with not IPv6 version o Packet with invalid source address o Packet with invalid destination address Note that in the base type library, definitions for exception ID and validate error ID metadata are applied to both IPv4Validator and IPv6Validator LFBs, i.e., the two LFBs share the same medadata definition, with different ID assignment inside. 5.2.2.2. Components This LFB has only one struct component, the IPv6ValidatorStatisticsType, which defines a set of statistics for validation process, including the number of bad header packets, the number of bad total length packets, and the number of bad hop limit packets. 5.2.2.3. Capabilities This LFB does not have a list of capabilities 5.2.2.4. Events This LFB does not have any events specified. 5.3. IP Forwarding LFBs IP Forwarding LFBs are specifically defined to abstract the IP forwarding processes. As definitions for a base LFB library, this Wang, et al. Expires September 1, 2012 [Page 56] Internet-Draft ForCES LFB Library February 2012 document restricts its LFB definition scope only to IP unicast forwarding. IP multicast may be defined in future documents. A typical IP unicast forwarding job is usually realized by looking up the forwarding information table to find next hop information, and then based on the next hop information, forwarding packets to specific physical output ports. It usually takes two steps to do so, firstly to look up a forwarding information table by means of Longest Prefix Matching(LPM) rule to find a next hop index, then to use the index as a search key to look up a next hop information table to find enough information to submit packets to output ports. This document abstracts the forwarding processes mainly based on the two steps model. However, there actually exists other models, like one which may only have a forwarding information base that have conjoined next hop information together with forwarding information. In this case, if ForCES technology is to be applied, some translation work will have to be done in the FE to translate attributes defined by this document into attributes related to the implementation. Based on the IP forwarding abstraction, two kind of typical IP unicast forwarding LFBs are defined, Unicast LPM lookup LFB and next hop application LFB. They are further distinguished by IPv4 and IPv6 protocols. 5.3.1. IPv4UcastLPM The IPv4UcastLPM LFB abstracts the IPv4 unicast Longest Prefix Match (LPM) process. This LFB also provides facilities to support users to implement equal-cost multi-path routing (ECMP) or reverse path forwarding (RPF). However, this LFB itself does not provide ECMP or RPF. To fully implement ECMP or RPF, additional specific LFBs, like a specific ECMP LFB or an RPF LFB, will have to be defined. This work may be done in the future version of the document. 5.3.1.1. Data Handling This LFB performs the IPv4 unicast LPM table looking up. It always expects as input IPv4 unicast packets from one singleton input known as "PktsIn". Then the LFB uses the destination IPv4 address of every packet as search key to look up the IPv4 prefix table and generate a hop selector as the matching result. The hop selector is passed as packet metadata to downstream LFBs, and will usually be used there as a search index to find more next hop information. Three singleton output LFB ports are defined. Wang, et al. Expires September 1, 2012 [Page 57] Internet-Draft ForCES LFB Library February 2012 The first singleton output known as "NormalOut" outputs IPv4 unicast packets that succeed the LPM lookup and (got a hop selector). The hop selector is associated with the packet as a metadata. Downstream from the LPM LFB is usually a next hop application LFB, like an IPv4NextHop LFB. The second singleton output known as "ECMPOut" is defined to provide support for users wishing to implement ECMP. An ECMP flag is defined in the LPM table to enable the LFB to support ECMP. When a table entry is created with the flag set true, it indicates this table entry is for ECMP only. A packet, which has passed through this prefix lookup, will always output from "ECMPOut" output port, with the hop selector being its lookup result. The output will usually directly go to a downstream ECMP processing LFB, where the hop selector can usually further generate optimized one or multiple next hop routes by use of ECMP algorithms. A default route flag is defined in the LPM table to enable the LFB to support a default route as well as loose RPF. When this flag is set true, the table entry is identified a default route which also implies that the route is forbidden for RPF. If a user wants to implement RPF on FE, a specific RPF LFB will have to be defined. In such RPF LFB, a component can be defined as an alias of the prefix table component of this LFB as described below. The final singleton output is known as "ExceptionOut" and is defined to allow exception packets to output here, along with an ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: o The packet failed the LPM lookup of the prefix table. The upstream LFB of this LFB is usually IPv4Validator LFB. If RPF is to be adopted, the upstream can be an RPF LFB, when defined. The downstream LFB is usually IPv4NextHop LFB. If ECMP is adopted, the downstream can be an ECMP LFB, when defined. 5.3.1.2. Components This LFB has two components. The IPv4PrefixTable component is defined as an array component of the LFB. Each row of the array contains an IPv4 address, a Prefix length, a Hop Selector, an ECMP flag and a Default Route flag. The LFB uses the destination IPv4 address of every input packet as search key to look up this table in order extract a next hop selector. The Wang, et al. Expires September 1, 2012 [Page 58] Internet-Draft ForCES LFB Library February 2012 ECMP flag is for the LFB to support ECMP. The default route flag is for the LFB to support a default route and for loose RPF. The IPv4UcastLPMStats component is a struct component which collects statistics information, including the total number of input packets received, the IPv4 packets forwarded by this LFB and the number of IP datagrams discarded due to no route found. 5.3.1.3. Capabilities This LFB does not have a list of capabilities 5.3.1.4. Events This LFB does not have any events specified. 5.3.2. IPv4NextHop This LFB abstracts the process of selecting ipv4 next hop action. 5.3.2.1. Data Handling The LFB abstracts the process of next hop information application to IPv4 packets. It receives an IPv4 packet with an associated next hop identifier (HopSelector), and uses the identifier as a table index to look up a next hop table to find an appropriate LFB output port. The LFB is expected to receive unicast IPv4 packets, via a singleton input known as "PktsIn" along with a HopSelector metadata which is used as a table index to lookup the NextHop table. The data processing involves the forwarding TTL decrement and IP checksum recalculation. Two output LFB ports are defined. The first output is a group output port known as "SuccessOut". On successful data processing the packet is sent out an LFB-port from within the LFB port group as selected by the LFBOutputSelectIndex value of the matched table entry. The packet is sent to a downstream LFB alongside with the L3PortID and MediaEncapInfoIndex metadata. The second output is a singleton output port known as "ExceptionOut", which will output packets for which the data processing failed, along with an additional ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: Wang, et al. Expires September 1, 2012 [Page 59] Internet-Draft ForCES LFB Library February 2012 o The HopSelector for the packet is invalid. o The packet failed lookup of the next hop table even though the HopSelector is valid. o The MTU for outgoing interface is less than the packet size. Downstream LFB instances could be either a BasicMetadataDispatch type (Section 5.5.1), used to fan out to different LFB instances or a media encapsulation related type, such as an EtherEncap type or a RedirectOut type(Section 5.4.2). For example, if there are Ethernet and other tunnel Encapsulation, then a BasicMetadataDispatch LFB can use the L3PortID metadata (Section 5.3.2.2) to dispatch packets to different encapsulator. 5.3.2.2. Components This LFB has only one component named IPv4NextHopTable which is defined as an array. The HopSelector received is used to match the array index of IPv4NextHopTable to find out a row of the table as the next hop information result. Each row of the array is a struct containing: o The L3PortID, which is the ID of the Logical Output Port that is passed onto the downstream LFB instance. This ID indicates what port to the neighbor is as defined by L3. Usually this ID is used for the next hop LFB to distinguish packets that need different L2 encapsulating. For instance, some packets may require general Ethernet encapsulation while others may require various types of tunnel encapsulations. In such case, different L3PortIDs are assigned to the packets and are as metadata passed to downstream LFB. A BasicMetadataDispatch LFB(Section 5.5.1) may have to be applied as the downstream LFB so as to dispatch packets to different encapsulation LFB instances according to the L3PortIDs. o MTU, the Maximum Transmission Unit for the outgoing port. o NextHopIPAddr, the IPv4 next hop address. o MediaEncapInfoIndex, the index we pass onto the downstream encapsulation LFB instance and that is used there as a search key to lookup a table (typically media encapsulation related) for further encapsulation information. The search key looks up the table by matching the table index.Note that an encapsulation LFB instance may not directly follow the next hop LFB, but the index is passed as a metadata associated, as such an encapsulation LFB instance even further downstream to the next hop LFB can still use the index. In some cases, depending on implementation, the CE may Wang, et al. Expires September 1, 2012 [Page 60] Internet-Draft ForCES LFB Library February 2012 set the MediaEncapInfoIndex passed downstream to a value that will fail lookup when it gets to a target encapsulation LFB; such a lookup failure at that point is an indication that further resolution is needed. For an example of this approach refer to Section 7.2 which talks about ARP and mentions this approach. o LFBOutputSelectIndex, the LFB Group output port index to select downstream LFB port. It is a 1-to-1 mapping with FEObject LFB's table LFBTopology (See [RFC5812]) component FromPortIndex corresponding to the port group mapping FromLFBID as IPv4NextHop LFB instance. 5.3.2.3. Capabilities This LFB does not have a list of capabilities 5.3.2.4. Events This LFB does not have any events specified. 5.3.3. IPv6UcastLPM The IPv6UcastLPM LFB abstracts the IPv6 unicast Longest Prefix Match (LPM) process. The definition of this LFB is similar to the IPv4UcastLPM LFB except that all IP addresses refer to IPv6 addresses. This LFB also provides facilities to support users to implement equal-cost multi-path routing (ECMP) or reverse path forwarding (RPF). However, this LFB itself does not provide ECMP or RPF. To fully implement ECMP or RPF, additional specific LFBs, like a specific ECMP LFB or an RPF LFB, will have to be defined. This work may be done in the future version of the document. 5.3.3.1. Data Handling This LFB performs the IPv6 unicast LPM table look up. It always expects as input IPv6 unicast packets from one singleton input known as "PktsIn". The destination IPv6 address of an incoming packet is used as search key to look up the IPv6 prefix table and generate a hop selector. This hop selector result is associated to the packet as a metadata and sent to downstream LFBs, and will usually be used in downstream LFBs as a search key to find more next hop information. Three singleton output LFB ports are defined. The first singleton output known as "NormalOut" outputs IPv6 unicast packets that succeed the LPM lookup (and got a hop selector). The Wang, et al. Expires September 1, 2012 [Page 61] Internet-Draft ForCES LFB Library February 2012 hop selector is associated with the packet as a metadata. Downstream from the LPM LFB is usually a next hop application LFB, like an IPv6NextHop LFB. The second singleton output known as "ECMPOut" is defined to provide support for users wishing to implement ECMP. An ECMP flag is defined in the LPM table to enable the LFB to support ECMP. When a table entry is created with the flag set true, it indicates this table entry is for ECMP only. A packet, which has passed through this prefix lookup, will always output from "ECMPOut" output port, with the hop selector being its lookup result. The output will usually directly go to a downstream ECMP processing LFB, where the hop selector can usually further generate optimized one or multiple next hop routes by use of ECMP algorithms. A default route flag is defined in the LPM table to enable the LFB to support a default route as well as loose RPF. When this flag is set true, the table entry is identified a default route which also implies that the route is forbidden for RPF. If a user wants to implement RPF on FE, a specific RPF LFB will have to be defined. In such RPF LFB, a component can be defined as an alias of the prefix table component of this LFB as described below. The final singleton output is known as "ExceptionOut" and is defined to allow exception packets to output here, along with an ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: o The packet failed the LPM lookup of the prefix table. The upstream LFB of this LFB is usually IPv6Validator LFB. If RPF is to be adopted, the upstream can be an RPF LFB, when defined. The downstream LFB is usually an IPv6NextHop LFB. If ECMP is adopted, the downstream can be an ECMP LFB, when defined. 5.3.3.2. Components This LFB has two components. The IPv6PrefixTable component is defined as an array component of the LFB. Each row of the array contains an IPv6 address, a Prefix length, a Hop Selector, an ECMP flag and a Default Route flag. The ECMP flag is so the LFB can support ECMP. The default route flag is for the LFB to support a default route and for loose RPF as described earlier. Wang, et al. Expires September 1, 2012 [Page 62] Internet-Draft ForCES LFB Library February 2012 The IPv6UcastLPMStats component is a struct component which collects statistics information, including the total number of input packets received, the IPv6 packets forwarded by this LFB and the number of IP datagrams discarded due to no route found. 5.3.3.3. Capabilities This LFB does not have a list of capabilities 5.3.3.4. Events This LFB does not have any events specified. 5.3.4. IPv6NextHop This LFB abstracts the process of selecting IPv6 next hop action. 5.3.4.1. Data Handling The LFB abstracts the process of next hop information application to IPv6 packets. It receives an IPv6 packet with an associated next hop identifier (HopSelector), and uses the identifier to look up a next hop table to find an appropriate output port from the LFB. The LFB is expected to receive unicast IPv6 packets, via a singleton input known as "PktsIn" along with a HopSelector metadata which is used as a table index to lookup the next hop table. Two output LFB ports are defined. The first output is a group output port known as "SuccessOut". On successful data processing the packet is sent out an LFB port from within the LFB port group as selected by the LFBOutputSelectIndex value of the matched table entry. The packet is sent to a downstream LFB alongside with the L3PortID and MediaEncapInfoIndex metadata. The second output is a singleton output port known as "ExceptionOut", which will output packets for which the data processing failed, along with an additional ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: o The HopSelector for the packet is invalid. o The packet failed lookup of the next hop table even though the HopSelector is valid. o The MTU for outgoing interface is less than the packet size. Wang, et al. Expires September 1, 2012 [Page 63] Internet-Draft ForCES LFB Library February 2012 Downstream LFB instances could be either a BasicMetadataDispatch type, used to fan out to different LFB instances or a media encapsulatation related type, such as an EtherEncap type or a RedirectOut type. For example, when the downstream LFB is BasicMetadataDispatch, and there exist Ethernet and other tunnel Encapsulation downstream from BasicMetadataDispatch, then the BasicMetadataDispatch LFB can use the L3PortID metadata (See section below) to dispatch packets to the different encapsulator LFBs. 5.3.4.2. Components This LFB has only one component named IPv6NextHopTable which is defined as an array. The array index of IPv6NextHopTable is used for a HopSelector to find out a row of the table as the next hop information. Each row of the array is a struct containing: o The L3PortID, which is the ID of the Logical Output Port that is passed onto the downstream LFB instance. This ID indicates what port to the neighbor is as defined by L3. Usually this ID is used for the next hop LFB to distinguish packets that need different L2 encapsulating. For instance, some packets may require general Ethernet encapsulation while others may require various types of tunnel encapsulations. In such case, different L3PortIDs are assigned to the packets and are as metadata passed to downstream LFB. A BasicMetadataDispatch LFB(Section 5.5.1) may have to be applied as the downstream LFB so as to dispatch packets to different encapsulation LFB instances according to the L3PortIDs. o MTU, the Maximum Transmission Unit for the outgoing port. o NextHopIPAddr, the IPv6 next hop address. o MediaEncapInfoIndex, the index we pass onto the downstream encapsulation LFB instance and that is used there as a search key to lookup a table (typically media encapsulation related) for further encapsulation information. The saearch key looks up the table by matching the table index. Note that an encapsulation LFB instance may not directly follow the next hop LFB, but the index is passed as a metadata associated, as such an encapsulation LFB instance even further downstream to the next hop LFB can still use the index. In some cases, depending on implementation, the CE may set the MediaEncapInfoIndex passed downstream to a value that will fail lookup when it gets to a target encapsulation LFB; such a lookup failure at that point is an indication that further resolution is needed. For an example of this approach refer to Section 7.2 which talks about ARP and mentions this approach. Wang, et al. Expires September 1, 2012 [Page 64] Internet-Draft ForCES LFB Library February 2012 o LFBOutputSelectIndex, the LFB Group output port index to select downstream LFB port. It is a 1-to-1 mapping with FEObject LFB's table LFBTopology (See [RFC5812]) component FromPortIndex corresponding to the port group mapping FromLFBID as IPv4NextHop LFB instance. 5.3.4.3. Capabilities This LFB does not have a list of capabilities 5.3.4.4. Events This LFB does not have any events specified. 5.4. Redirect LFBs Redirect LFBs abstract data packets transportation process between CE and FE. Some packets output from some LFBs may have to be delivered to CE for further processing, and some packets generated by CE may have to be delivered to FE and further to some specific LFBs for data path processing. According to [RFC5810], data packets and their associated metadata are encapsulated in ForCES redirect message for transportation between CE and FE. We define two LFBs to abstract the process, a RedirectIn LFB and a RedirectOut LFB. Usually, in an LFB topology of an FE, only one RedirectIn LFB instance and one RedirectOut LFB instance exist. 5.4.1. RedirectIn RedirectIn LFB abstracts the process for the CE to inject data packets into the FE data path. 5.4.1.1. Data Handling A RedirectIn LFB abstracts the process for the CE to inject data packets into the FE LFB topology so as to input data packets into FE data paths. From LFB topology point of view, the RedirectIn LFB acts as a source point for data packets coming from CE, therefore RedirectIn LFB is defined with a single output LFB port (and no input LFB port). The single output port of RedirectIn LFB is defined as a group output type, with the name of "PktsOut". Packets produced by this output will have arbitrary frame types decided by the CE which generated the packets. Possible frames may include IPv4, IPv6, or ARP protocol packets. The CE may associate some metadata to indicate the frame types and may also associate other metadata to indicate various information on the packets. Among them, there MUST exist a Wang, et al. Expires September 1, 2012 [Page 65] Internet-Draft ForCES LFB Library February 2012 'RedirectIndex' metadata, which is an integer acting as an index. When the CE transmits the metadata along with the packet to a RedirectIn LFB, the LFB will read the RedirectIndex metadata and output the packet to one of its group output port instance, whose port index is indicated by this metadata. Any other metadata, in addition to 'RedirectIndex', will be passed untouched along the packet delivered by the CE to downstream LFB. This means the 'RedirectIndex' metadata from CE will be "consumed" by the RedirectIn LFB and will not be passed to downstream LFB. Note that, a packet from CE without a 'RedirectIndex' metadata associated will be dropped by the LFB. 5.4.1.2. Components There are no components defined for the current version of RedirectIn LFB. 5.4.1.3. Capabilities This LFB does not have a list of capabilities 5.4.1.4. Events This LFB does not have any events specified. 5.4.2. RedirectOut RedirectOut LFB abstracts the process for LFBs in the FE to deliver data packets to the CE. 5.4.2.1. Data Handling A RedirectOut LFB abstracts the process for LFBs in the FE to deliver data packets to the CE. From the LFB's topology point of view, the RedirectOut LFB acts as a sink point for data packets going to the CE, therefore RedirectOut LFB is defined with a single input LFB port (and no output LFB port). The RedirectOut LFB has only one singleton input known as "PktsIn", but is capable of receiving packets from multiple LFBs by multiplexing this input. The input expects any kind of frame type therefore the frame type has been specified as arbitrary, and also all types of metadata are expected. All associated metadata produced (but not consumed) by previous processed LFBs should be delivered to CE via the ForCES protocol redirect message [RFC5810]. The CE can decide on how to process the redirected packet by referencing the associated metadata. As an example, a packet could be redirected by the FE to the CE because the EtherEncap LFB is not able to resolve L2 Wang, et al. Expires September 1, 2012 [Page 66] Internet-Draft ForCES LFB Library February 2012 information. The metadata "ExceptionID", created by the EtherEncap LFB is passed along with the packet and should be sufficient for the CE to do the necessary processing and resolve the L2 entry required. 5.4.2.2. Components There are no components defined for the current version of RedirectOut LFB. 5.4.2.3. Capabilities This LFB does not have a list of capabilities 5.4.2.4. Events This LFB does not have any events specified. 5.5. General Purpose LFBs 5.5.1. BasicMetadataDispatch The BasicMetadataDispatch LFB is defined to abstract the process in which a packet is dispatched to some output path based on its associated metadata value. 5.5.1.1. Data Handling The BasicMetadataDispatch has only one singleton input known as "PktsIn". Every input packet should be associated with a metadata that will be used by the LFB to do the dispatch. This LFB contains a metadata ID and a dispatch table named MetadataDispatchTable, all configured by the CE. The metadata ID specifies which metadata is to be used for dispatching packets. The MetadataDispatchTable contains entries of a metadata value and an OutputIndex, specifying that the packet with the metadata value must go out from the LFB group output port instance with the OutputIndex. Two output LFB ports are defined. The first output is a group output port known as "PktsOut". A packet with its associated metadata having found an OutputIndex by successfully looking up the dispatch table will be output to the group port instance with the corresponding index. The second output is a singleton output port known as "ExceptionOut", which will output packets for which the data processing failed, along with an additional ExceptionID metadata to indicate what caused the exception. Currently defined exception types include: Wang, et al. Expires September 1, 2012 [Page 67] Internet-Draft ForCES LFB Library February 2012 o There is no matching when looking up the metadata dispatch table. As an example, if the CE decides to dispatch packets according to a physical port ID (PHYPortID), the CE may set the ID of PHYPortID metadata to the LFB first. Moreover, the CE also sets the PHYPortID actual values (the metadata values) and assigned OutputIndex for the values to the dispatch table in the LFB. When a packet arrives, a PHYPortID metadata is found associated with the packet, the metadata value is further used as a key to look up the dispatch table to find out an output port instance for the packet. Currently the BasicMetadataDispatch LFB only allows the metadata value of the dispatch table entry be 32-bits integer. A metadata with other types of value is not supported in this version. A more complex metadata dispatch LFB may be defined in future version of the library. In that LFB, multiple tuples of metadata with more value types supported may be used to dispatch packets. 5.5.1.2. Components This LFB has two components. One component is MetadataID and the other is MetadataDispatchTable. Each row entry of the dispatch table is a struct containing metadata value and the OutputIndex. Note that currently, the metadata value is only allowed to be 32-bits integer. The metadata value is also defined as a content key for the table. The concept of content key is a searching key for tables which is defined in the ForCES FE Model [RFC5812]. With the content key, CE can manipulate the table by means of a specific metadata value rather than by the table index only. See [RFC5812] document and also the ForCES Protocol [RFC5810] for more details on the definition and use of a content key. 5.5.1.3. Capabilities This LFB does not have a list of capabilities 5.5.1.4. Events This LFB does not have any events specified. 5.5.2. GenericScheduler This is a preliminary generic scheduler LFB for abstracting a simple scheduling process. Wang, et al. Expires September 1, 2012 [Page 68] Internet-Draft ForCES LFB Library February 2012 5.5.2.1. Data Handling There exist various kinds of scheduling strategies with various implementations. As a base LFB library, this document only defines a preliminary generic scheduler LFB for abstracting a simple scheduling process. Users may use this LFB as a basic scheduler LFB to further construct more complex scheduler LFBs by means of inheritance as described in [RFC5812]. Packets of any arbitrary frame type are received via a group input known as "PktsIn" with no additional metadata expected. This group input is capable of multiple input port instances. Each port instance may be connected to different upstream LFB output. Inside the LFB, it is abstracted that each input port instance is connected to a queue, and the queue is marked with a queue ID whose value is exactly the same as the index of corresponding group input port instance. Scheduling disciplines are applied to all queues and also all packets in the queues.The group input port property PortGroupLimits in ObjectLFB as defined by ForCES FE model[RFC5810] provides means for the CE to query the capability of total queue numbers the scheduler supports. The CE can then decide how many queues it may use for a scheduling application. Scheduled packets are output from a singleton output port of the LFB knows as "PktsOut" with no corresponding metadata. More complex scheduler LFBs may be defined with more complex scheduling disciplines by succeeding this LFB. For instance, a priority scheduler LFB may be defined by inheriting this LFB and defining a component to indicate priorities for all input queues. 5.5.2.2. Components The SchedulingDiscipline component is for the CE to specify a scheduling discipline to the LFB. Currently defined scheduling disciplines only include Round Robin (RR) strategy. The default scheduling discipline is RR then. The QueueStats component is defined to allow CE to query every queue status of the scheduler. It is an array component and each row of the array is a struct containing a queue ID. Currently defined queue status includes the queue depth in packets and the queue depth in bytes. Using the queue ID as the index, the CE can query every queue for its used length in unit of packets or bytes. Wang, et al. Expires September 1, 2012 [Page 69] Internet-Draft ForCES LFB Library February 2012 5.5.2.3. Capabilities The following capability is currently defined for the GenericScheduler. o The queue length limit providing the storage ability for every queue. 5.5.2.4. Events This LFB does not have any events specified. Wang, et al. Expires September 1, 2012 [Page 70] Internet-Draft ForCES LFB Library February 2012 6. XML for LFB Library EtherPHYCop The EtherPHYCop LFB describes an Ethernet interface abstracted at physical layer. It limits the physical media to copper. 1.0 EtherPHYIn The input port of the EtherPHYCop LFB. It expects any type of Ethernet frame. EthernetAll EtherPHYOut The output port of the EtherPHYCop LFB. The output packet has the same Ethernet frame type with the input packet, associated with a metadata indicating the ID of the physical port. EthernetAll PHYPortID Wang, et al. Expires September 1, 2012 [Page 71] Internet-Draft ForCES LFB Library February 2012 PHYPortID The identification of the physical port uint32 AdminStatus The port status administratively requested PortStatusType 2 OperStatus The actual operational status of the port PortStatusType AdminLinkSpeed The port link speed administratively requested LANSpeedType LAN_SPEED_AUTO OperLinkSpeed The actual operational link speed of the port LANSpeedType AdminDuplexMode The port duplex mode administratively requested DuplexType Auto Wang, et al. Expires September 1, 2012 [Page 72] Internet-Draft ForCES LFB Library February 2012 OperDuplexMode The actual operational duplex mode of the port DuplexType CarrierStatus The carrier status of the port boolean false SupportedLinkSpeed A list of link speeds the port supports LANSpeedType SupportedDuplexMode A list of duplex modes the port supports DuplexType PHYPortStatusChanged An event reports change on operational status of the physical port. OperStatus OperStatus Wang, et al. Expires September 1, 2012 [Page 73] Internet-Draft ForCES LFB Library February 2012 LinkSpeedChanged An event reports change on operational link speed of the physical port. OperLinkSpeed OperLinkSpeed DuplexModeChanged An event reports change on operational duplex mode of the physical port. OperDuplexMode OperDuplexMode EtherMACIn EtherMACIn LFB abstracts an Ethernet port at MAC data link layer. This LFB describes Ethernet processing functions like MAC address locality check, deciding if the Ethernet packets should be bridged, providing Ethernet layer flow control, etc. 1.0 Wang, et al. Expires September 1, 2012 [Page 74] Internet-Draft ForCES LFB Library February 2012 EtherPktsIn The input port of the EtherMACIn LFB. It expects any type of Ethernet frame. EthernetAll PHYPortID NormalPathOut An output port called normal path output in the EtherMACIn LFB. It outputs Ethernet packets to downstream LFBs for normal processing like Ethernet packet classification and further L3 processing. EthernetAll PHYPortID L2BridgingPathOut An output port called L2 bridging path output in the EtherMACIn LFB. It outputs Ethernet packets to downstream LFBs for layer 2 bridging processing. The port is switched on or off by the L2BridgingPathEnable flag. EthernetAll Wang, et al. Expires September 1, 2012 [Page 75] Internet-Draft ForCES LFB Library February 2012 PHYPortID AdminStatus The LFB status administratively requested, which has the same data type with a port status. Default is in 'down' status. PortStatusType 2 LocalMACAddresses Local MAC addresses of the Ethernet port the LFB represents. IEEEMAC L2BridgingPathEnable A flag indicating if the LFB L2 BridgingPath output port is enabled or not. Default is not. boolean false PromiscuousMode A flag indicating whether the LFB is in promiscuous mode or not. Default is not. boolean false TxFlowControl A flag indicating whether transmit flow control is Wang, et al. Expires September 1, 2012 [Page 76] Internet-Draft ForCES LFB Library February 2012 applied or not. Default is not. boolean false RxFlowControl A flag indicating whether receive flow control is applied or not. Default is not. boolean false MACInStats The statistics of the EtherMACIn LFB MACInStatsType EtherClassifier EtherClassifier LFB abstracts the process to decapsulate Ethernet packets and then classifies them into various network layer packets according to information in the Ethernet headers. It is expected the LFB classifies packets by packet types like IPv4, IPv6, MPLS, ARP, ND, etc. 1.0 EtherPktsIn Input port of Ethernet packets. A PHYPortID metadata is associated and a LogicalPortID metadata is optionally associated with every packet. EthernetAll PHYPortID Wang, et al. Expires September 1, 2012 [Page 77] Internet-Draft ForCES LFB Library February 2012 LogicalPortID ClassifyOut A group port for output of Ethernet classifying results. Arbitrary PHYPortID SrcMAC DstMAC EtherType VlanID VlanPriority ExceptionOut A single port for output of all Ethernet packets that fail the classifying process. An ExceptionID metadata indicates the failure reason. Arbitrary ExceptionID EtherDispatchTable An EtherDispatchTable array component is defined in Wang, et al. Expires September 1, 2012 [Page 78] Internet-Draft ForCES LFB Library February 2012 the LFB to dispatch every Ethernet packet to output group according to logical port ID assigned by the VlanInputTable and Ethernet type in the Ethernet packet header. EtherDispatchTableType VlanInputTable A VlanInputTable array component is defined in the LFB to classify VLAN Ethernet packets. Every input packet is assigned with a new LogicalPortID according to the packet incoming port ID and the VLAN ID. VlanInputTableType EtherClassifyStats A table records statistics on the Ethernet classifying process in the LFB. EtherClassifyStatsTableType EtherEncap This LFB abstracts the process of encapsulating Ethernet headers onto received packets. The encapsulation is based on passed metadata. 1.0 EncapIn A port inputs IPv4 and/or IPv6 packets for encapsulation. A MediaEncapInfoIndex metadata is expected and a VLAN priority metadata is optionally expected with every input packet. IPv4 IPv6 Wang, et al. Expires September 1, 2012 [Page 79] Internet-Draft ForCES LFB Library February 2012 MediaEncapInfoIndex VlanPriority SuccessOut Output port for packets which have found Ethernet L2 information and have been successfully encapsulated into an Ethernet packet. An L2portID metadata is produced for every packet. IPv4 IPv6 L2PortID ExceptionOut Output port for all packets that fail encapsulation in the LFB. An ExceptionID metadata indicates failure reason. IPv4 IPv6 ExceptionID MediaEncapInfoIndex VlanPriority Wang, et al. Expires September 1, 2012 [Page 80] Internet-Draft ForCES LFB Library February 2012 EncapTable An array for Ethernet encapsulation information lookup.Each row of the array contains destination MAC address, source MAC address, VLAN ID, and output logical L2 port ID. EncapTableType EtherMACOut EtherMACOut LFB abstracts an Ethernet port at MAC data link layer. It specifically describes Ethernet packet process for output to physical port. A downstream LFB is usually an Ethernet physical LFB like EtherPHYcop LFB.Ethernet output functions are closely related to Ethernet input functions, therefore some components defined in this LFB are as alias of EtherMACIn LFB. 1.0 EtherPktsIn The input port of the EtherMACOut LFB. It expects any type of Ethernet frame. EthernetAll PHYPortID EtherPktsOut A port to output all Ethernet packets,each with a metadata indicating the physical port ID the packet Wang, et al. Expires September 1, 2012 [Page 81] Internet-Draft ForCES LFB Library February 2012 is to go through. EthernetAll PHYPortID AdminStatus The LFB status administratively requested, which has the same data type with a port status. It is defined as alias of AdminStatus component in EtherMACIn LFB. PortStatusType MTU Maximum transmission unit (MTU) uint32 TxFlowControl A flag indicating whether transmit flow control is applied, defined as alias of TxFlowControl component in EtherMACIn LFB. boolean RxFlowControl A flag indicating whether receive flow control is applied, defined as alias of RxFlowControl component in EtherMACIn LFB. boolean MACOutStats Wang, et al. Expires September 1, 2012 [Page 82] Internet-Draft ForCES LFB Library February 2012 The statistics of the EtherMACOut LFB MACOutStatsType IPv4Validator The IPv4Validator LFB performs IPv4 validation according to [RFC5812]. The IPv4 packet will be output to the corresponding port regarding of the validation result, whether the packet is unicast, multicast or whether an exception has occurred or the validation failed. 1.0 ValidatePktsIn Input port for data packets to be validated Arbitrary IPv4UnicastOut Output port for validated IPv4 unicast packets IPv4Unicast IPv4MulticastOut Output port for validated IPv4 multicast packets Wang, et al. Expires September 1, 2012 [Page 83] Internet-Draft ForCES LFB Library February 2012 IPv4Multicast ExceptionOut Output port for all packets with exceptional cases when validating. An ExceptionID metadata indicates the exception case type. IPv4 ExceptionID FailOut Output port for packets failed validating process. A ValidateErrorID metadata indicates the error type or failure reason. IPv4 ValidateErrorID IPv4ValidatorStats The statistics information for validating process in the LFB. IPv4ValidatorStatsType Wang, et al. Expires September 1, 2012 [Page 84] Internet-Draft ForCES LFB Library February 2012 IPv6Validator The IPv6Validator LFB performs IPv6 validation according to [RFC2460]. The IPv6 packet will be output to the corresponding port regarding of the validation result, whether the packet is a unicast or a multicast one, an exception has occurred or the validation failed. 1.0 ValidatePktsIn Input port for data packets to be validated Arbitrary IPv6UnicastOut Output port for validated IPv6 unicast packets IPv6Unicast IPv6MulticastOut Output port for validated IPv6 multicast packets IPv6Multicast ExceptionOut Wang, et al. Expires September 1, 2012 [Page 85] Internet-Draft ForCES LFB Library February 2012 Output port for packets with exceptional cases when validating. An ExceptionID metadata indicates the exception case type. IPv6 ExceptionID FailOut Output port for packets failed validating process. A ValidateErrorID metadata indicates the error type or failure reason. IPv6 ValidateErrorID IPv6ValidatorStats The statistics information for validating process in the LFB. IPv6ValidatorStatsType IPv4UcastLPM The IPv4UcastLPM LFB abstracts the IPv4 unicast Longest Prefix Match (LPM) process. This LFB also provides facilities to support users to implement equal-cost Wang, et al. Expires September 1, 2012 [Page 86] Internet-Draft ForCES LFB Library February 2012 multi-path routing (ECMP) or reverse path forwarding (RPF). However, this LFB itself does not provide ECMP or RPF. 1.0 PktsIn A port for input of packets to be processed. IPv4 unicast packets are expected. IPv4Unicast NormalOut A normal output port outputs IPv4 unicast packets that succeed the LPM lookup. A HopSelector metadata is produced for every packet for downstream LFB to do next hop action. IPv4Unicast HopSelector ECMPOut The port outputs packets that need further ECMP processing. An ECMP processing LFB is usually followed the output. If ECMP is not required, no downstream LFB may be connected to the port. IPv4Unicast Wang, et al. Expires September 1, 2012 [Page 87] Internet-Draft ForCES LFB Library February 2012 HopSelector ExceptionOut The port outputs all packets with exceptional cases when doing LPM process. An ExceptionID metadata associated indicates what caused the exception. IPv4Unicast ExceptionID IPv4PrefixTable A table for IPv4 longest prefix match. The destination IPv4 address of every input packet is used as a search key to look up the table to find out a next hop selector. IPv4PrefixTableType IPv4UcastLPMStats The statistics information for IPv4 unicast longest prefix match process in the LFB. IPv4UcastLPMStatsType IPv6UcastLPM The IPv6UcastLPM LFB abstracts the IPv6 unicast Longest Prefix Match (LPM) process. This LFB also provides Wang, et al. Expires September 1, 2012 [Page 88] Internet-Draft ForCES LFB Library February 2012 facilities to support users to implement equal-cost multi-path routing (ECMP) or reverse path forwarding (RPF). However, this LFB itself does not provide ECMP or RPF. 1.0 PktsIn A port for input of packets to be processed. IPv6 unicast packets are expected. IPv6Unicast NormalOut A normal output port outputs IPv6 unicast packets that succeed the LPM lookup. A HopSelector metadata is produced for every packet for downstream LFB to do next hop action. IPv6Unicast HopSelector ECMPOut The port outputs packets that need further ECMP processing. An ECMP processing LFB is usually followed the output. If ECMP is not required, no downstream LFB may be connected to the port. IPv6Unicast Wang, et al. Expires September 1, 2012 [Page 89] Internet-Draft ForCES LFB Library February 2012 HopSelector ExceptionOut The port outputs all packets with exceptional cases when doing LPM process. An ExceptionID metadata associated indicates what caused the exception. IPv6Unicast ExceptionID IPv6PrefixTable A table for IPv6 longest prefix match. The destination IPv6 address of every input packet is used as a search key to look up the table to find out a next hop selector. IPv6PrefixTableType IPv6UcastLPMStats The statistics information for IPv6 unicast longest prefix match process in the LFB. IPv6UcastLPMStatsType IPv4NextHop The LFB abstracts the process of next hop information Wang, et al. Expires September 1, 2012 [Page 90] Internet-Draft ForCES LFB Library February 2012 application to IPv4 packets. It receives an IPv4 packet with an associated next hop identifier (HopSelector), and uses the identifier as a table index to look up a next hop table to find an appropriate LFB output port. The data processing also involves the forwarding TTL decrement and IP checksum recalculation. 1.0 PktsIn A port for input of unicast IPv4 packets, along with a HopSelector metadata which is used as a table index to lookup the next hop table in the LFB. IPv4Unicast HopSelector SuccessOut The group output port for packets successfully found next hop information. The group output port index for every packet is decided by the LFBOutputSelectIndex value assigned in the next hop table entry. The packet is sent to a downstream LFB along with an L3PortID, a NextHopIPv4Addr, and optionally a MediaEncapInfoIndex metadata. IPv4Unicast L3PortID NextHopIPv4Addr MediaEncapInfoIndex Wang, et al. Expires September 1, 2012 [Page 91] Internet-Draft ForCES LFB Library February 2012 ExceptionOut The output port for packets with exceptional or failure cases when doing next hop action. An ExceptionID metadata indicates what caused the case. IPv4Unicast ExceptionID IPv4NextHopTable The IPv4NextHopTable is defined as an array. A HopSelector is used to match the array index of the table to find out a row of the table as the next hop information result. Each row of the array is a struct containing the L3PortID, MTU, NextHopIPAddr(IPv4 type), MediaEncapInfoIndex, and LFBOutputSelectIndex. IPv4NextHopTableType IPv6NextHop The LFB abstracts the process of next hop information application to IPv6 packets. It receives an IPv6 packet with an associated next hop identifier (HopSelector), and uses the identifier as a table index to look up a next hop table to find an appropriate LFB output port. 1.0 PktsIn Wang, et al. Expires September 1, 2012 [Page 92] Internet-Draft ForCES LFB Library February 2012 A port for input of unicast IPv6 packets, along with a HopSelector metadata which is used as a table index to lookup the next hop table in the LFB. IPv6Unicast HopSelector SuccessOut The group output port for packets successfully found next hop information. The group output port index for every packet is decided by the LFBOutputSelectIndex value assigned in the next hop table entry. The packet is sent to a downstream LFB along with an L3PortID, a NextHopIPv6Addr, and optionally a MediaEncapInfoIndex metadata. IPv6Unicast L3PortID NextHopIPv6Addr MediaEncapInfoIndex ExceptionOut The output port for packets with exceptional or failure cases when doing next hop action. An ExceptionID metadata indicates what caused the case. IPv6Unicast Wang, et al. Expires September 1, 2012 [Page 93] Internet-Draft ForCES LFB Library February 2012 ExceptionID IPv6NextHopTable The IPv6NextHopTable is defined as an array. A HopSelector is used to match the array index of the table to find out a row of the table as the next hop information result. Each row of the array is a struct containing the L3PortID, MTU, NextHopIPAddr(IPv6 type), MediaEncapInfoIndex, and LFBOutputSelectIndex. IPv6NextHopTableType RedirectIn A RedirectIn LFB abstracts the process for the ForCES CE to inject data packets into the ForCES FE LFB topology so as to input data packets into FE data paths. 1.0 PktsOut The output port of RedirectIn LFB is defined as a group output type. Packets produced by this output will have arbitrary frame types decided by the CE which generated the packets. From LFB topology point of view, the RedirectIn LFB acts as a source point for data packets coming from CE, therefore RedirectIn LFB is defined with a single output LFB port (and no input LFB port). The CE may associate some metadata to indicate the frame types and may also associate other metadata to indicate information on the packets. Among them, there must exist a 'RedirectIndex' metadata, which is an integer acting as an index. When the CE transmits the metadata along with the packet to a RedirectIn LFB, the LFB will read the RedirectIndex Wang, et al. Expires September 1, 2012 [Page 94] Internet-Draft ForCES LFB Library February 2012 metadata and output the packet to one of its group output port instance, whose port index is indicated by this metadata. Any other metadata, in addition to 'RedirectIndex', will be passed untouched along the packet delivered by the CE to downstream LFB. This means the 'RedirectIndex' metadata from CE will be "consumed" by the RedirectIn LFB and will not be passed to downstream LFB. Note that, a packet from CE without a 'RedirectIndex' metadata associated will be dropped by the LFB. Arbitrary RedirectOut A RedirectOut LFB abstracts the process for LFBs in the ForCES FE to deliver data packets to the ForCES CE. 1.0 PktsIn The input port for the RedirectOut LFB. From the LFB's topology point of view, the RedirectOut LFB acts as a sink point for data packets going to the CE, therefore RedirectOut LFB is defined with a single input LFB port (and no output LFB port). The port expects all types of packet frames and metadata. All associated metadata produced (but not consumed) by previous processed LFBs should be delivered to the CE. Arbitrary Wang, et al. Expires September 1, 2012 [Page 95] Internet-Draft ForCES LFB Library February 2012 BasicMetadataDispatch The BasicMetadataDispatch LFB is defined to abstract the process in which a packet is dispatched to some output path based on its associated metadata value. Current version of the LFB only allows the metadata value be 32-bits integer. 1.0 PktsIn The packet input port for dispatching. Every input packet should be associated with a metadata that will be used by the LFB to do the dispatch. Arbitrary Arbitrary PktsOut The group output port outputs dispatching results. A packet with its associated metadata having found an OutputIndex by successfully looking up the dispatch table will be output to the group port instance with the corresponding index. Arbitrary ExceptionOut The output port outputs packets for which the data processing failed, along with an additional ExceptionID metadata to indicate what caused the Wang, et al. Expires September 1, 2012 [Page 96] Internet-Draft ForCES LFB Library February 2012 exception. Arbitrary ExceptionID MetadataID The metadata ID specifies which metadata is to be used for dispatching packets. It is configured by the CE. uint32 MetadataDispatchTable The MetadataDispatchTable contains entries of a Metadata value and an OutputIndex, specifying that packet with the metadata value must go out from the LFB group output port instance with the OutputIndex. Note that in current version, the metadata value is only allowed to be 32-bits integer. The metadata value is also defined as a content key for the table. MetadataDispatchTableType GenericScheduler This is a preliminary generic scheduler LFB for abstracting a simple scheduling process. Users may use this LFB as a basic scheduler LFB to further construct more complex scheduler LFBs by means of inheritance as described in RFC5812. 1.0 Wang, et al. Expires September 1, 2012 [Page 97] Internet-Draft ForCES LFB Library February 2012 PktsIn A group input port. Packets of any arbitrary frame type are received via the group input with no additional metadata expected. Inside the LFB, it is abstracted that each input port instance is connected to a queue, and the queue is marked with a queue ID whose value is exactly the same as the index of corresponding group input port instance. Scheduling disciplines are applied to all queues and also all packets in the queues.The group input port property provides means for the CE to query the capability of total queue numbers the scheduler supports. Arbitrary PktsOut An output port scheduled packets are output from with no must metadata associated. Arbitrary SchedulingDiscipline The SchedulingDiscipline component is for the CE to specify a scheduling discipline to the LFB. SchdDisciplineType 1 QueueStats Wang, et al. Expires September 1, 2012 [Page 98] Internet-Draft ForCES LFB Library February 2012 The QueueStats component is defined to allow the CE to query every queue statistics in the scheduler. QueueStatsTableType QueueLenLimit Allowed maximium length of each queue. The length unit is in bytes. uint32 Wang, et al. Expires September 1, 2012 [Page 99] Internet-Draft ForCES LFB Library February 2012 7. LFB Class Use Cases This section demonstrates examples on how the LFB classes defined by the Base LFB library in Section 6 can be applied to achieve some typical router functions. The functions demonstrated are: o IPv4 forwarding o ARP processing It is assumed the LFB topology on the FE described has already been established by the CE and maps to the use cases illustrated in this section. The use cases demonstrated in this section are mere examples and by no means should be treated as the only way one would construct router functionality from LFBs; based on the capability of the FE(s), a CE should be able to express different NE applications. 7.1. IPv4 Forwarding Figure 1 (Section 3.2.3) shows a typical IPv4 forwarding processing path by use of the base LFB classes. A number of EtherPHYCop LFB(Section 5.1.1) instances are used to describe physical layer functions of the ports. PHYPortID metadata is generated by EtherPHYCop LFB and is used by all the subsequent downstream LFBs. An EtherMACIn LFB(Section 5.1.2), which describe the MAC layer processing, follows every EtherPHYCop LFB. The EtherMACIn LFB may do a locality check of MAC addresses if the CE configures the appropriate EtherMACIn LFB component. Ethernet packets out of the EtherMACIn LFB are sent to an EtherClassifier LFB (Section 5.1.3) to be decapsulated and classified into network layer types like IPv4, IPv6, ARP, etc. In the example use case, every physical Ethernet interface is associated with one Classifier instance; although not illustrated, it is also feasible that all physical interfaces are associated with only one Ethernet Classifier instance. EtherClassifier uses the PHYPortID metadata, the Ethernet type of the input packet, and VlanID (if present in the input Ethernet packets), to decide the packet network layer type and the LFB output port to the downstream LFB. The EtherClassifier LFB also assigns a new logical port ID metadata to the packet for later use. The EtherClassifier may also generate some new metadata for every packet like EtherType, SrcMAC, DstMAC, LogicPortID, etc for consumption by downstream LFBs. Wang, et al. Expires September 1, 2012 [Page 100] Internet-Draft ForCES LFB Library February 2012 If a packet is classified as an IPv4 packet, it is sent downstream to an IPv4Validator LFB (Section 5.2.1) to validate the IPv4 packet. In the validator LFB, IPv4 packets are validated and are additionally classified into either IPv4 unicast packets or multicast packets. IPv4 unicast packets are sent to downstream to the IPv4UcastLPM LFB (Section 5.3.1). The IPv4UcastLPM LFB is where the longest prefix match decision is made, and a next hop selection is selected. The next hop ID metadata is generated by the IPv4UcastLPM LFB to be consumed downstream by the IPv4NextHop LFB (Section 5.3.2). The IPv4NextHop LFB uses the next hop ID metadata to do derive where the packet is to go next and the media encapsulation type for the port, etc. The IPv4NextHop LFB generates the L3PortID metadata used to identify a next hop output physical/logical port. In the example use case, the next hop output port is an Ethernet type; as a result, the packet and its L3 port ID metadata are sent downstream to an EtherEncap LFB (Section 5.1.4). The EtherEncap LFB encapsulates the incoming packet into an Ethernet frame. A BasicMetadataDispatch LFB (Section 5.5.1) follows the EtherEncap LFB. The BasicMetadataDispatch LFB is where packets are finally dispatched to different output physical/logical ports based on the L3PortID metadata sent to the LFB. 7.2. ARP processing Figure 2 shows the processing path for ARP protocol in the case the CE implements the ARP processing function. By no means is this the only way ARP processing could be achieved; as an example ARP processing could happen at the FE - but that discussion is out of scope for this use case. Wang, et al. Expires September 1, 2012 [Page 101] Internet-Draft ForCES LFB Library February 2012 +---+ +---+ | | ARP packets | | | |-------------->---------+--->| | To CE ...-->| | . | | | | | . | +---+ | | . | RedirectOut +---+ ^ Ether EtherEncap | IPv4 packets lack Classifier +---+ | address resolution information | | | Packets need | |--------->---+ ...--------->| | L2 Encapsulation| | +---+ | | +------+ | | +-->| |--+ +---+ |Ether | | | | +---+ | | |--------->|MACOut|-->... From CE| |--+ +-->| | . +------+ | |ARP Packets | | . | |from CE | | . +------+ | | | |--------> |Ether |-->... +---+ +---+ |MACOut| RedirectIn BasicMetadata +------+ Dispatch Figure 2: LFB use case for ARP There are two ways ARP processing could be triggered in the CE as illustrated in Figure 2: o ARP packets arriving from outside of the NE. o IPV4 packets failing to resolve within the FE. ARP packets from network interfaces are filtered out by EtherClassifier LFB. The classified ARP packets and associated metadata are then sent downstream to the RedirectOut LFB (Section 5.4.2) to be transported to CE. The EtherEncap LFB, as described earlier, receives packets that need Ethernet L2 encapsulating. When the EtherEncap LFB fails to find the necessary L2 Ethernet information to encapsulate the packet with, it outputs the packet to its ExceptionOut LFB port. Downstream to EtherEncap LFB's ExceptionOut LFB port is the RedirectOut LFB which transports the packet to the CE (Section 5.1.4 on EtherEncap LFB for details). To achieve its goal, the CE needs to generate ARP request and response packets and send them to external (to the NE) networks. ARP Wang, et al. Expires September 1, 2012 [Page 102] Internet-Draft ForCES LFB Library February 2012 request and response packets from the CE are redirected to an FE via a RedirectIn LFB (Section 5.4.1). As was the case with forwarded IPv4 packets, outgoing ARP packets are also encapsulated to Ethernet format by the EtherEncap LFB, and then dispatched to different interfaces via a BasicMetadataDispatch LFB. The BasicMetadataDispatch LFB dispatches the packets according to the L3PortID metadata included in every ARP packet sent from CE. Wang, et al. Expires September 1, 2012 [Page 103] Internet-Draft ForCES LFB Library February 2012 8. Contributors The authors would like to thank Jamal Hadi Salim, Ligang Dong, and Fenggen Jia who made major contributions to the development of this document. Jamal Hadi Salim Mojatatu Networks Ottawa, Ontario Canada Email: hadi@mojatatu.com Ligang Dong Zhejiang Gongshang University 149 Jiaogong Road Hangzhou 310035 P.R.China Phone: +86-571-28877751 EMail: donglg@mail.zjgsu.edu.cn Fenggen Jia National Digital Switching Center(NDSC) Jianxue Road Zhengzhou 452000 P.R.China EMail: jfg@mail.ndsc.com.cn Wang, et al. Expires September 1, 2012 [Page 104] Internet-Draft ForCES LFB Library February 2012 9. Acknowledgements This document is based on earlier documents from Joel Halpern, Ligang Dong, Fenggen Jia and Weiming Wang. Wang, et al. Expires September 1, 2012 [Page 105] Internet-Draft ForCES LFB Library February 2012 10. IANA Considerations IANA has created a registry of ForCES LFB Class Names and the corresponding ForCES LFB Class Identifiers, with the location of the definition of the ForCES LFB Class, in accordance with the rules to use the namespace. The LFB library in this document needs for unique class names and numeric class identifiers of all LFBs. Besides, this document also needs to define the following namespaces: o Metadata ID, defined in Section 4.3 and Section 4.4 o Exception ID, defined in Section 4.4 o Validate Error ID, defined in Section 4.4 10.1. LFB Class Names and LFB Class Identifiers LFB classes defined by this document belongs to IETF defined LFBs by Standard Track RFCs. According to IANA, the identifier namespace for these LFB classes is from 3 to 65535. The assignment of LFB class names and LFB class identifiers is as in the following table. +-----------+---------------+------------------------+--------------+ | LFB Class | LFB Class Name| Description | Reference | | Identifier| | | | +-----------+---------------+------------------------+--------------+ | 3 | EtherPHYCop | Define an Ethernet port| RFC????(this| | | | abstracted at physical | document) | | | | layer. | Section 5.1.1| | | | | | | 4 | EtherMACIn | Define an Ethernet | RFC???? | | | | input port at MAC data | Section 5.1.2| | | | link layer. | | | | | | | | 5 |EtherClassifier| Define the process to | RFC???? | | | | decapsulate Ethernet | Section 5.1.3| | | | packets and classify | | | | | the packets. | | | | | | | | 6 | EtherEncap | Define the process to | RFC???? | | | | encapsulate IP packets | Section 5.1.4| | | | to Ethernet packets. | | | | | | | Wang, et al. Expires September 1, 2012 [Page 106] Internet-Draft ForCES LFB Library February 2012 | 7 | EtherMACOut | Define an Ethernet | RFC ???? | | | | output port at MAC | Section 5.1.5| | | | data link layer. | | | | | | | | 8 | IPv4Validator | Perform IPv4 packets | RFC ???? | | | | validation. | Section 5.2.1| | | | | | | 9 | IPv6Validator | Perform IPv6 packets | RFC ???? | | | | validation. | Section 5.2.2| | | | | | | 10 | IPv4UcastLPM | Perform IPv4 Longest | RFC ???? | | | | Prefix Match Lookup. | Section 5.3.1| | | | | | | 11 | IPv6UcastLPM | Perform IPv6 Longest | RFC ???? | | | | Prefix Match Lookup. | Section 5.3.3| | | | | | | 12 | IPv4NextHop | Define the process of | RFC ??? | | | | selecting Ipv4 next hop| Section 5.3.2| | | | action. | | | | | | | | 13 | IPv6NextHop | Define the process of | RFC ??? | | | | selecting Ipv6 next hop| Section 5.3.4| | | | action. | | | | | | | | 14 | RedirectIn | Define the process for | RFC ??? | | | | CE to inject data | Section 5.4.1| | | | packets into FE LFB | | | | | topology. | | | | | | | | 15 | RedirectOut | Define the process for | RFC ??? | | | | LFBs in FE to deliver | Section 5.4.2| | | | data packets to CE. | | | | | | | | 16 | BasicMetadata | Dispatch input packets | RFC ??? | | | Dispatch | to a group output | Section 5.5.1| | | | according to a metadata| | | | | | | | 17 | Generic | Define a preliminary | RFC ???? | | | Scheduler | generic scheduling | Section 5.5.2| | | | process. | | +-----------+---------------+------------------------+--------------+ Table 1 Wang, et al. Expires September 1, 2012 [Page 107] Internet-Draft ForCES LFB Library February 2012 10.2. Metadata ID The Metadata ID namespace is 32 bits long. The following is the guideline for managing the namespace. Metadata ID 0x00000000-0x7FFFFFFF Metadata with IDs in this range are Specification Required [RFC5226]. A metadata ID using this range MUST be documented in an RFC or other permanent and readily available references. Values assigned by this specification: +--------------+-------------------------+--------------------------+ | Value | Name | Definition | +--------------+-------------------------+--------------------------+ | 0x00000001 | PHYPortID | See Section 4.4 | | 0x00000002 | SrcMAC | See Section 4.4 | | 0x00000003 | DstMAC | See Section 4.4 | | 0x00000004 | LogicalPortID | See Section 4.4 | | 0x00000005 | EtherType | See Section 4.4 | | 0x00000006 | VlanID | See Section 4.4 | | 0x00000007 | VlanPriority | See Section 4.4 | | 0x00000008 | NextHopIPv4Addr | See Section 4.4 | | 0x00000009 | NextHopIPv6Addr | See Section 4.4 | | 0x0000000A | HopSelector | See Section 4.4 | | 0x0000000B | ExceptionID | See Section 4.4 | | 0x0000000C | ValidateErrorID | See Section 4.4 | | 0x0000000D | L3PortID | See Section 4.4 | | 0x0000000E | RedirectIndex | See Section 4.4 | | 0x0000000F | MediaEncapInfoIndex | See Section 4.4 | +--------------+-------------------------+--------------------------+ Table 2 Metadata ID 0x80000000-0xFFFFFFFF Metadata IDs in this range are reserved for vendor private extensions and are the responsibility of individuals. 10.3. Exception ID The Exception ID namespace is 32 bits long. The following is the guideline for managing the namespace. Wang, et al. Expires September 1, 2012 [Page 108] Internet-Draft ForCES LFB Library February 2012 Exception ID 0x00000000-0x7FFFFFFF Exception IDs in this range are Specification Required [RFC5226]. An exception ID using this range MUST be documented in an RFC or other permanent and readily available references. Values assigned by this specification: +--------------+---------------------------------+------------------+ | Value | Name | Definition | +--------------+---------------------------------+------------------+ | 0x00000000 | AnyUnrecognizedExceptionCase | See Section 4.4 | | 0x00000001 | ClassifyNoMatching | See Section 4.4 | | 0x00000002 | MediaEncapInfoIndexInvalid | See Section 4.4 | | 0x00000003 | EncapTableLookupFailed | See Section 4.4 | | 0x00000004 | BadTTL | See Section 4.4 | | 0x00000005 | IPv4HeaderLengthMismatch | See Section 4.4 | | 0x00000006 | RouterAlertOptions | See Section 4.4 | | 0x00000007 | IPv6HopLimitZero | See Section 4.4 | | 0x00000008 | IPv6NextHeaderHBH | See Section 4.4 | | 0x00000009 | SrcAddressExecption | See Section 4.4 | | 0x0000000A | DstAddressExecption | See Section 4.4 | | 0x0000000B | LPMLookupFailed | See Section 4.4 | | 0x0000000C | HopSelectorInvalid | See Section 4.4 | | 0x0000000D | NextHopLookupFailed | See Section 4.4 | | 0x0000000E | FragRequired | See Section 4.4 | | 0x0000000F | MetadataNoMatching | See Section 4.4 | +--------------+---------------------------------+------------------+ Table 3 Exception ID 0x80000000-0xFFFFFFFF Exception IDs in this range are reserved for vendor private extensions and are the responsibility of individuals. 10.4. Validate Error ID The Validate Error ID namespace is 32 bits long. The following is the guideline for managing the namespace. Validate Error ID 0x00000000-0x7FFFFFFF Validate Error IDs in this range are Specification Required [RFC5226]. A Validate Error ID using this range MUST be documented in an RFC or other permanent and readily available references. Wang, et al. Expires September 1, 2012 [Page 109] Internet-Draft ForCES LFB Library February 2012 Values assigned by this specification: +--------------+---------------------------------+------------------+ | Value | Name | Definition | +--------------+---------------------------------+------------------+ | 0x00000000 | AnyUnrecognizedValidateErrorCase| See Section 4.4 | | 0x00000001 | InvalidIPv4PacketSize | See Section 4.4 | | 0x00000002 | NotIPv4Packet | See Section 4.4 | | 0x00000003 | InvalidIPv4HeaderLengthSize | See Section 4.4 | | 0x00000004 | InvalidIPv4LengthFieldSize | See Section 4.4 | | 0x00000005 | InvalidIPv4Checksum | See Section 4.4 | | 0x00000006 | InvalidIPv4SrcAddr | See Section 4.4 | | 0x00000007 | InvalidIPv4DstAddr | See Section 4.4 | | 0x00000008 | InvalidIPv6PakcetSize | See Section 4.4 | | 0x00000009 | NotIPv6Packet | See Section 4.4 | | 0x0000000A | InvalidIPv6SrcAddr | See Section 4.4 | | 0x0000000B | InvalidIPv6DstAddr | See Section 4.4 | +--------------+---------------------------------+------------------+ Table 4 Validate Error ID 0x80000000-0xFFFFFFFF Validate Error IDs in this range are reserved for vendor private extensions and are the responsibility of individuals. Wang, et al. Expires September 1, 2012 [Page 110] Internet-Draft ForCES LFB Library February 2012 11. Security Considerations The ForCES framework document [RFC3746] provides a comprehensive security analysis for the overall ForCES architecture. For example, the ForCES protocol entities must be authenticated per the ForCES requirements before they can access the information elements described in this document via ForCES. Access to the information contained in this document is accomplished via the ForCES protocol[RFC5810], which is defined in separate documents, and thus the security issues will be addressed there. Wang, et al. Expires September 1, 2012 [Page 111] Internet-Draft ForCES LFB Library February 2012 12. References 12.1. Normative References [RFC5810] Doria, A., Hadi Salim, J., Haas, R., Khosravi, H., Wang, W., Dong, L., Gopal, R., and J. Halpern, "Forwarding and Control Element Separation (ForCES) Protocol Specification", RFC 5810, March 2010. [RFC5812] Halpern, J. and J. Hadi Salim, "Forwarding and Control Element Separation (ForCES) Forwarding Element Model", RFC 5812, March 2010. 12.2. Informative References [RFC1122] Braden, R., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, October 1989. [RFC1812] Baker, F., "Requirements for IP Version 4 Routers", RFC 1812, June 1995. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC Text on Security Considerations", BCP 72, RFC 3552, July 2003. [RFC3654] Khosravi, H. and T. Anderson, "Requirements for Separation of IP Control and Forwarding", RFC 3654, November 2003. [RFC3746] Yang, L., Dantu, R., Anderson, T., and R. Gopal, "Forwarding and Control Element Separation (ForCES) Framework", RFC 3746, April 2004. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. Wang, et al. Expires September 1, 2012 [Page 112] Internet-Draft ForCES LFB Library February 2012 Authors' Addresses Weiming Wang Zhejiang Gongshang University 18 Xuezheng Str., Xiasha University Town Hangzhou, 310018 P.R.China Phone: +86 571 28877721 Email: wmwang@zjsu.edu.cn Evangelos Haleplidis University of Patras Patras, Greece Email: ehalep@ece.upatras.gr Kentaro Ogawa NTT Corporation Tokyo, Japan Email: ogawa.kentaro@lab.ntt.co.jp Chuanhuang Li Hangzhou H3C Tech. Co., Ltd. 310 Liuhe Road, Zhijiang Science Park Hangzhou, 310053 P.R.China Phone: +86 571 86760000 Email: chuanhuang_li@zjsu.edu.cn Halpern Joel Ericsson P.O. Box 6049 Leesburg, 20178 VA Phone: +1 703 371 3043 Email: joel.halpern@ericsson.com Wang, et al. Expires September 1, 2012 [Page 113]