Internet Engineering Task Force W. Wang Internet-Draft Zhejiang Gongshang University Intended status: Standards Track E. Haleplidis Expires: December 4, 2011 University of Patras K. Ogawa NTT Corporation C. Li Hangzhou BAUD Networks J. Halpern Ericsson June 2, 2011 ForCES Logical Function Block (LFB) Library draft-ietf-forces-lfb-lib-04 Abstract This document defines basic classes of Logical Function Blocks (LFBs) used in the Forwarding and Control Element Separation (ForCES). It is defined according to ForCES FE model [RFC5812] and ForCES protocol [RFC5810] specifications. These basic LFB classes are scoped to meet requirements of typical router functions and considered as the basic LFB library for ForCES. Descriptions of individual LFBs are presented and detailed XML definitions are included in the library. Several use cases of the defined LFB classes are also proposed. 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 December 4, 2011. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. Wang, et al. Expires December 4, 2011 [Page 1] Internet-Draft ForCES LFB Library June 2011 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 . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1. Scope of the Library . . . . . . . . . . . . . . . . . . . 7 3.2. Overview of LFB Classes in the Library . . . . . . . . . . 9 3.2.1. LFB Design Choices . . . . . . . . . . . . . . . . . . 9 3.2.2. LFB Class Groupings . . . . . . . . . . . . . . . . . 9 3.2.3. Sample LFB Class Application . . . . . . . . . . . . . 11 3.3. Document Structure . . . . . . . . . . . . . . . . . . . . 12 4. Base Types . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.1. Data . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.2. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.3. MetaData . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.4. XML for Base Type Library . . . . . . . . . . . . . . . . 15 5. LFB Class Description . . . . . . . . . . . . . . . . . . . . 36 5.1. Ethernet Processing LFBs . . . . . . . . . . . . . . . . . 36 5.1.1. EtherPHYCop . . . . . . . . . . . . . . . . . . . . . 36 5.1.1.1. Data Handling . . . . . . . . . . . . . . . . . . 36 5.1.1.2. Components . . . . . . . . . . . . . . . . . . . . 37 5.1.1.3. Capabilities . . . . . . . . . . . . . . . . . . . 38 5.1.1.4. Events . . . . . . . . . . . . . . . . . . . . . . 38 5.1.2. EtherMACIn . . . . . . . . . . . . . . . . . . . . . . 38 5.1.2.1. Data Handling . . . . . . . . . . . . . . . . . . 38 5.1.2.2. Components . . . . . . . . . . . . . . . . . . . . 39 5.1.2.3. Capabilities . . . . . . . . . . . . . . . . . . . 40 5.1.2.4. Events . . . . . . . . . . . . . . . . . . . . . . 40 5.1.3. EtherClassifier . . . . . . . . . . . . . . . . . . . 40 5.1.4. EtherEncapsulator . . . . . . . . . . . . . . . . . . 42 5.1.5. EtherMACOut . . . . . . . . . . . . . . . . . . . . . 45 5.1.5.1. Data Handling . . . . . . . . . . . . . . . . . . 45 5.1.5.2. Components . . . . . . . . . . . . . . . . . . . . 45 5.1.5.3. Capabilities . . . . . . . . . . . . . . . . . . . 46 5.1.5.4. Events . . . . . . . . . . . . . . . . . . . . . . 46 5.2. IP Packet Validation LFBs . . . . . . . . . . . . . . . . 46 Wang, et al. Expires December 4, 2011 [Page 2] Internet-Draft ForCES LFB Library June 2011 5.2.1. IPv4Validator . . . . . . . . . . . . . . . . . . . . 46 5.2.1.1. Data Handling . . . . . . . . . . . . . . . . . . 46 5.2.1.2. Components . . . . . . . . . . . . . . . . . . . . 48 5.2.1.3. Capabilities . . . . . . . . . . . . . . . . . . . 48 5.2.1.4. Events . . . . . . . . . . . . . . . . . . . . . . 48 5.2.2. IPv6Validator . . . . . . . . . . . . . . . . . . . . 48 5.2.2.1. Data Handling . . . . . . . . . . . . . . . . . . 48 5.2.2.2. Components . . . . . . . . . . . . . . . . . . . . 50 5.2.2.3. Capabilities . . . . . . . . . . . . . . . . . . . 50 5.2.2.4. Events . . . . . . . . . . . . . . . . . . . . . . 50 5.3. IP Forwarding LFBs . . . . . . . . . . . . . . . . . . . . 50 5.3.1. IPv4UcastLPM . . . . . . . . . . . . . . . . . . . . . 51 5.3.2. IPv4NextHop . . . . . . . . . . . . . . . . . . . . . 52 5.3.3. IPv6UcastLPM . . . . . . . . . . . . . . . . . . . . . 54 5.3.4. IPv6NextHop . . . . . . . . . . . . . . . . . . . . . 54 5.4. Redirect LFBs . . . . . . . . . . . . . . . . . . . . . . 54 5.4.1. RedirectIn . . . . . . . . . . . . . . . . . . . . . . 54 5.4.2. RedirectOut . . . . . . . . . . . . . . . . . . . . . 55 5.5. General Purpose LFBs . . . . . . . . . . . . . . . . . . . 55 5.5.1. BasicMetadataDispatch . . . . . . . . . . . . . . . . 56 5.5.2. GenericScheduler . . . . . . . . . . . . . . . . . . . 56 6. XML for LFB Library . . . . . . . . . . . . . . . . . . . . . 58 7. LFB Class Use Cases . . . . . . . . . . . . . . . . . . . . . 80 7.1. IP Forwarding . . . . . . . . . . . . . . . . . . . . . . 80 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 81 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 82 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 83 11. Security Considerations . . . . . . . . . . . . . . . . . . . 84 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 85 12.1. Normative References . . . . . . . . . . . . . . . . . . . 85 12.2. Informative References . . . . . . . . . . . . . . . . . . 85 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 86 Wang, et al. Expires December 4, 2011 [Page 3] Internet-Draft ForCES LFB Library June 2011 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 December 4, 2011 [Page 4] Internet-Draft ForCES LFB Library June 2011 2. Definitions This document follows the terminology defined by the ForCES Requirements in [RFC3654]and by the ForCES framework in [RFC3746]. 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 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). 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 Wang, et al. Expires December 4, 2011 [Page 5] Internet-Draft ForCES LFB Library June 2011 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. 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. Wang, et al. Expires December 4, 2011 [Page 6] Internet-Draft ForCES LFB Library June 2011 3. Introduction RFC 3746 [RFC3746] 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. RFC 5810 [RFC5810] specifies the ForCES protocol. RFC 5812 [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. RFC 1812 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: o Encapsulating and decapsulating the IP datagrams with the connected network framing (e.g., an Ethernet header and checksum), o 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, o Translating the IP destination address into an appropriate network-level address for the connected network (e.g., an Ethernet hardware address), if needed, and o Responding to network flow control and error indications, if any. Wang, et al. Expires December 4, 2011 [Page 7] Internet-Draft ForCES LFB Library June 2011 (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 forwards Internet datagrams. Important issues in this process are buffer management, congestion control, and fairness. o Recognizes error conditions and generates ICMP error and information messages as required. o Drops datagrams whose time-to-live fields have reached zero. o 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 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 way 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 deal with Ethernet physical media. Other future documents may deal with other types 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. Wang, et al. Expires December 4, 2011 [Page 8] Internet-Draft ForCES LFB Library June 2011 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: (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 types like POS or ATM may be incorporated in the library in future version of the document or in a future separate Wang, et al. Expires December 4, 2011 [Page 9] Internet-Draft ForCES LFB Library June 2011 document. The following LFBs are defined for Ethernet processing: EtherPHYCop (section 5.1.1) EtherMACIn (section 5.1.2) EtherClassifier (section 5.1.3) EtherEncapsulator (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 5.3.4) 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 5.5.1) RedirectOut (section 5.5.2) (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: Wang, et al. Expires December 4, 2011 [Page 10] Internet-Draft ForCES LFB Library June 2011 BasicMetadataDispatch (section 5.6.1) GenericScheduler (section 5.6.2) 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 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 missed. Section 7.1 will describe the LFB topology in more details. Wang, et al. Expires December 4, 2011 [Page 11] Internet-Draft ForCES LFB Library June 2011 +-----+ +------+ | | | | | |<---------------|Ether |<----------------------------+ | | |MACOut| | | | | | | |Ether| +------+ | |PHY | | |Cop | +---+ | |#1 | +-----+ | |----->IPv6 Packets | | | | | | | +----+ | | | |Ether| | | | | | | |->|MACIn|-->| |IPv4| | | +-----+ | | | |-+->| | +---+ | +-----+ +--+ | | |unicast +-----+ | | | Ether | | |------->| | | | | . Classifier| | |packet |IPv4 | | | | . | | | |Ucast|->| |--+ | . | | | |LPM | | | | | +---+ | +----+ +-----+ | | | | +-----+ | | | IPv4 +---+ | | | | | | | Validator IPv4 | | +-----+ |Ether| | |-+ NextHop | | | |->|MACIn|-->| |IPv4 | | | | | | | |----->IPv6 Packets | | |Ether| +-----+ +---+ +----+ | | |PHY | Ether | | | | |Cop | Classifier | | +-------+ | | |#n | | | | | | | | | +------+ | |<--| Ether |<-+ | | | | |<------| | | Encap | | | |<---------------|Ether | ...| | +-------+ | | | |MACOut| +---| | | | | | | | +----+ | +-----+ +------+ | BasicMetadataDispatch | +-------------------------+ Figure 1: AIPv4 Forwarding Case 3.3. Document Structure Base type definitions, including data types, packet frame types, and etadata types are presented in advance for definitions of various LFB classes. Section 4 (Base Types Section) provide a description on the base types used by this LFB library. In order for an extensive use of these base types for other LFB class definitions, the base type definitions are provided by an xml file in a way as a library which is separate from the LFB definition library. Wang, et al. Expires December 4, 2011 [Page 12] Internet-Draft ForCES LFB Library June 2011 Within every group of LFB classes, a set of LFBs are defined for individual function purposes. Section 5 (LFB Class Descriptions Section) makes 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) provide 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 December 4, 2011 [Page 13] Internet-Draft ForCES LFB Library June 2011 4. Base Types TThe FE model [RFC5812] has specified the following data types as predefined (built-in) atomic data-types: char, uchar, int16, uint16, int32, uint32, int64, uint64, string[N], string, byte[N], boolean, octetstring[N], float16, float32, float64. Based on these 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 further be defined. To define a base LFB library for typical router functions, a base data types, frame types, and metadata types MUST be defined. This section provides a description of these types and detailed XML definitions for the base types. In order for extensive use of the base type definitions for LFB definitions other than this base LFB library, the base type definitions are provided with a separate xml library file labeled with "BaseTypeLibrary". Users can refer to this library by the statement: 4.1. Data The following data types are currently defined and put in the base type library: (TBD) 4.2. Frame According to FE model [RFC5812], frame types are used in LFB definitions to define the types of frames the LFB expects at its input port(s) and emits at its output port(s). The element in the FE model is used to define a new frame type. The following frame types are currently defined and put in the base type library as base frame types for the LFB library: (TBD) Wang, et al. Expires December 4, 2011 [Page 14] Internet-Draft ForCES LFB Library June 2011 4.3. MetaData 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 and put in the base type library as base metadata types for the LFB library definitions: (TBD) 4.4. XML for Base Type Library EthernetAll An kinds of Ethernet frame 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 Wang, et al. Expires December 4, 2011 [Page 15] Internet-Draft ForCES LFB Library June 2011 IPv6Unicast An IPv6 unicast packet IPv6Multicast An IPv6 multicast packet Arbitrary Any kinds of frames IPv4Addr IPv4 address byte[4] IPv6Addr IPv6 address byte[16] IEEEMAC IEEE mac. byte[6] LANSpeedType Network speed values uint32 LAN_SPEED_10M 10M Ethernet LAN_SPEED_100M 100M Ethernet LAN_SPEED_1G 1000M Ethernet Wang, et al. Expires December 4, 2011 [Page 16] Internet-Draft ForCES LFB Library June 2011 LAN_SPEED_10G 10G Ethernet LAN_SPEED_AUTO LAN speed auto DuplexType Duplex types uint32 Auto Auto negotitation. Half-duplex port negotitation half duplex Full-duplex port negotitation full duplex PortStatusValues The possible values of status. Used for both administrative and operation status. uchar Disabled the port is operatively disabled. UP the port is up. Wang, et al. Expires December 4, 2011 [Page 17] Internet-Draft ForCES LFB Library June 2011 Down The port is down. MACInStatsType The content of statistic for EtherMACIn. NumPacketsReceived The number of packets received. uint64 NumPacketsDropped The number of packets dropped. uint64 MACOutStatsType The content of statistic for EtherMACOut. NumPacketsTransmitted The number of packets transmitted. uint64 NumPacketsDropped The number of packets dropped. uint64 EtherDispatchEntryType the type of EtherDispatch table entry. LogicalPortID Logical port ID. uint32 Wang, et al. Expires December 4, 2011 [Page 18] Internet-Draft ForCES LFB Library June 2011 EtherType The EtherType value in the Ether head. uint32 OutputIndex Group output port index. uint32 EtherDispatchTableType the type of EtherDispatch table. EtherDispatchEntryType VlanInputTableEntryType Vlan input table entry type. IncomingPortID The incoming port ID. uint32 VlanID Vlan ID. uint32 LogicalPortID logical port ID. uint32 VlanInputTableType Vlan input table type. VlanInputTableEntryType Wang, et al. Expires December 4, 2011 [Page 19] Internet-Draft ForCES LFB Library June 2011 EtherClassifyStatsType Ether classify statistic information. EtherType The EtherType value uint32 PacketsNum Packets number uint64 EtherClassifyStatsTableType Ether classify statistic information table type. EtherClassifyStatsType IPv4ValidatorStatisticsType Statistics type in IPv4validator. badHeaderPkts Number of bad header packets. uint64 badTotalLengthPkts Number of bad total length packets. uint64 badTTLPkts Number of bad TTL packets. uint64 badChecksumPkts Number of bad checksum packets. uint64 Wang, et al. Expires December 4, 2011 [Page 20] Internet-Draft ForCES LFB Library June 2011 IPv6ValidatorStatisticsType Statistics type in IPv6validator. badHeaderPkts Number of bad header packets. uint64 badTotalLengthPkts Number of bad total length packets. uint64 badHopLimitPkts Number of bad Hop limit packets. uint64 IPv4PrefixInfoType IPv4 Prefix information,entry type for IPv4 prefix table. IPv4Address An IPv4 Address IPv4Addr Prefixlen The prefix length uchar HopSelector HopSelector is the nexthop ID which points to the nexthop table Wang, et al. Expires December 4, 2011 [Page 21] Internet-Draft ForCES LFB Library June 2011 uint32 ECMPFlag An ECMP Flag for this route boolean False This route does not have multiple nexthops. True This route has multiple nexthops. DefaultRouteFlag A Default Route Flag for supporting loose RPF. boolean False This is not a default route. True This route is a default route. for supporting the loose RPF. IPv4PrefixTableType IPv4 prefix table type. IPv4PrefixInfoType Wang, et al. Expires December 4, 2011 [Page 22] Internet-Draft ForCES LFB Library June 2011 IPv4UcastLPMStatsType Statistics type in IPv4Unicast. InRcvdPkts The total number of input packets received uint64 FwdPkts IPv4 packets forwarded by this LFB uint64 NoRoutePkts The number of IP datagrams discarded because no route could be found. uint64 IPv6PrefixInfoType IPv6 Prefix information,entry type for IPv6 prefix table IPv6Address An IPv6 Address IPv6Addr Prefixlen The prefix length uchar HopSelector HopSelector is the nexthop ID which points Wang, et al. Expires December 4, 2011 [Page 23] Internet-Draft ForCES LFB Library June 2011 to the nexthop table uint32 ECMPFlag An ECMP Flag for this route boolean False This route does not have multiple nexthops. True This route has multiple nexthops. DefaultRouteFlag A Default Route Flag. boolean False This is not a default route. True This route is a default route. IPv6PrefixTableType IPv6 prefix table type. IPv6PrefixInfoType Wang, et al. Expires December 4, 2011 [Page 24] Internet-Draft ForCES LFB Library June 2011 IPv6UcastLPMStatsType Statistics type in IPv6Unicast. InRcvdPkts The total number of input packets received uint64 FwdPkts IPv6 packets forwarded by this LFB uint64 NoRoutePkts The number of IP datagrams discarded because no route could be found. uint64 IPv4NextHopInfoType IPv4 next hop information. Entry type for the IPv4 next hop table. L3PortID The ID of the Logical/physical Output Port that we pass onto the neighboring LFB instance. This ID indicates what port to the neighbor is as defined by L3. uint32 MTU Maximum Transmission Unit for out going port. It is for desciding whether the packet need fragmentation uint32 NextHopIPAddr Next Hop IPv4 Address Wang, et al. Expires December 4, 2011 [Page 25] Internet-Draft ForCES LFB Library June 2011 IPv4Addr MediaEncapInfoIndex The index we pass onto the neighboring LFB instance. This index is used to lookup a table (typically media encapsulatation related) further downstream. uint32 LFBOutputSelectIndex LFB Group output port index to select downstream LFB port. Some possibilities of downstream LFB instances are: a) EtherEncapsulator b) Other type of media LFB c) A metadata Dispatcher d) A redirect LFB e) etc Note: LFBOutputSelectIndex is the FromPortIndex for the port group "successout" in the table LFBTopology (of FEObject LFB) as defined for the NH LFB. uint32 IPv4NextHopTableType IPv4 next hop table type IPv4NextHopInfoType IPv6NextHopInfoType IPv6 next hop information. Entry type for the IPv6NextHopTable. L3PortID The ID of the Logical/physical Output Port that we pass onto the neighboring LFB instance. This ID indicates what port to the neighbor is as defined by L3. uint32 Wang, et al. Expires December 4, 2011 [Page 26] Internet-Draft ForCES LFB Library June 2011 MTU Maximum Transmission Unit for out going port. It is for desciding whether the packet need fragmentation. uint32 NextHopIPAddr Next Hop IPv6 Address IPv6Addr MediaEncapInfoIndex The index we pass onto the neighboring LFB instance. This index is used to lookup a table (typically media encapsulatation related) further downstream. uint32 LFBOutputSelectIndex LFB Group output port index to select downstream LFB port. Some possibilities of downstream LFB instances are: a) EtherEncapsulator b) Other type of media LFB c) A metadata Dispatcher d) A redirect LFB e) etc Note: LFBOutputSelectIndex is the FromPortIndex for the port group "successout" in the table LFBTopology (of FEObject LFB) as defined for the NH LFB. uint32 IPv6NextHopTableType IPv6 next hop table type IPv6NextHopInfoType EncapTableEntryType Ethernet encapsulation table entry type. Wang, et al. Expires December 4, 2011 [Page 27] Internet-Draft ForCES LFB Library June 2011 DstMac Ethernet Mac of the Neighbor IEEEMAC SrcMac Source MAC used in encapsulation IEEEMAC VlanID VLAN ID. uint32 L2PortID Output logical L2 port ID. uint32 EncapTableType Ethernet encapsulation table type EncapTableEntryType MetadataDispatchType The entry type for Metadata dispatch table. MetadataID metadata ID uint32 MetadataValue metadata value. uint32 OutputIndex group output port index. Wang, et al. Expires December 4, 2011 [Page 28] Internet-Draft ForCES LFB Library June 2011 uint32 MetadataDispatchTableType Metadata dispatch table type. MetadataDispatchType SchdDisciplineType scheduling discipline type. uint32 FIFO First In First Out scheduler. RR Round Robin. QueueDepthType the entry type for queue depth table. QueueID Queue ID uint32 QueueDepthInPackets the Queue Depth when the depth units are packets. uint32 QueueDepthInBytes the Queue Depth when the depth units are bytes. Wang, et al. Expires December 4, 2011 [Page 29] Internet-Draft ForCES LFB Library June 2011 uint32 QueueDepthTableType the Depth of Queue table type. QueueDepthType PHYPortID The physical port ID that a packet has entered. 1 uint32 SrcMAC Source MAC Address 2 IEEEMAC DstMAC Destination MAC Address 3 IEEEMAC LogicalPortID ID of logical port. 4 uint32 EtherType The value of EtherType. 5 uint32 VlanID Vlan ID. 6 Wang, et al. Expires December 4, 2011 [Page 30] Internet-Draft ForCES LFB Library June 2011 uint32 VlanPriority The priority of Vlan. 7 uint32 NexthopIPv4Addr Nexthop IP address. 8 IPv4Addr NexthopIPv6Addr Nexthop IP address. 9 IPv6Addr HopSelector HopSelector is the nexthop ID which points to the nexthop table 10 uint32 ExceptionID Exception Types 11 uint32 Other Any other exception. BroadCastPacket Packet with destination address equal to 255.255.255.255 BadTTL The packet can't be forwarded as the TTL has expired. Wang, et al. Expires December 4, 2011 [Page 31] Internet-Draft ForCES LFB Library June 2011 IPv4HeaderLengthMismatch IPv4 Packet's header length is less than 5. LengthMismatch The packet length reported by link layer is less than the total length field. RouterAlertOptions Packet IP head include Router Alert options. RouteInTableNotFound There is no route in the route table corresponding to the packet destination address NextHopInvalid The NexthopID is invalid FragRequired The MTU for outgoing interface is less than the packet size. LocalDelivery The packet is for a local interface. GenerateICMP ICMP packet needs to be generated. PrefixIndexInvalid The prefixIndex is wrong. IPv6HopLimitZero Packet with Hop Limit zero Wang, et al. Expires December 4, 2011 [Page 32] Internet-Draft ForCES LFB Library June 2011 IPv6NextHeaderHBH Packet with next header set to Hop-by-Hop ValidateErrorID Validate Error Types 12 uint32 Other Any other validation error. InvalidIPv4PacketSize Packet size reported is less than 20 bytes. NotIPv4Packet Packet is not IP version 4. InvalidIPv4HeaderLengthSize Packet's header length is less than 5. InvalidIPv4Checksum Packet with invalid checksum. InvalidIPv4SrcAddr1 Packet with source address equal to 255.255.255.255. InvalidIPv4SrcAddr2 Packet with source address 0. InvalidIPv4SrcAddr3 Wang, et al. Expires December 4, 2011 [Page 33] Internet-Draft ForCES LFB Library June 2011 Packet with source address of form 127.any. InvalidIPv4SrcAddr4 Packet with source address in Class E domain. InvalidIPv6PakcetSize Packet size reported is less than 40 bytes. NotIPv6Packet Packet is not IP version 6. InvalidIPv6SrcAddr1 Packet with multicast source address (the MSB of the source address is 0xFF). InvalidIPv6SrcAddr2 Packet with source address set to loopback(::1). InvalidIPv6DstAddr1 Packet with destination set to 0 or ::1. L3PortID ID of L3 port. 13 uint32 RedirectIndex Redirect Output port index. 14 uint32 Wang, et al. Expires December 4, 2011 [Page 34] Internet-Draft ForCES LFB Library June 2011 MediaEncapInfoIndex The index for media encap table in Media encap LFB. 15 uint32 Wang, et al. Expires December 4, 2011 [Page 35] Internet-Draft ForCES LFB Library June 2011 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 RFC 5810 has already defined an 'FE Protocol LFB' which is as a logical entity in each FE to control the ForCES protocol. RFC 5812 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 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. 5.1. Ethernet Processing LFBs As the most popular physical and data link layer protocols, Ethernets are widely deployed. It becomes a basic requirement for a router to be able to process various Ethernet data packets. Note that there exist different versions of Ethernet protocols, 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 start work, 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 Wang, et al. Expires December 4, 2011 [Page 36] Internet-Draft ForCES LFB Library June 2011 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' metadatum, 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 EtherMacOut 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 adminstratively 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 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' metadatum at the LFB output and to associate it to every Ethernet packet this LFB receives. The metadatum 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 Wang, et al. Expires December 4, 2011 [Page 37] Internet-Draft ForCES LFB Library June 2011 specifies whether the port is linked with an operational connector. 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 This LFB is defined to be able to generate several events in which the CE may be interested. 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 negotiated duplex mode. 5.1.2. EtherMACIn EtherMACIn LFB abstracts an Ethernet port at MAC data link layer. It specifically describes Ethernet processing functions like MAC address locality check, deciding if the Ethernet packets should be bridged, provide 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 "EtherMACIn", which are usually output from some Ethernet physical layer LFB, like an EtherPHYCop LFB, alongside with a metadatum indicating the physical port ID that the packet comes. The LFB is defined with two separate singleton outputs. All Output packets are in Ethernet format, as received from the physical layer LFB and cover all types of Ethernet packets. The first singleton output is known as "NormalPathOut". It usually outputs Ethernet packets to some LFB like an EtherClassifier LFB for Wang, et al. Expires December 4, 2011 [Page 38] Internet-Draft ForCES LFB Library June 2011 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 can perform Ethernet layer flow control. This is usually implemented cooperatively by the EtherMACIn LFB and the EtherMACOut LFB. The flow control is further distinguished by Tx flow control and Rx flow control, separately for sending process and receiving process flow controls. 5.1.2.2. 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'. 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 Wang, et al. Expires December 4, 2011 [Page 39] Internet-Draft ForCES LFB Library June 2011 flow control on sending packets. The default value for is 'false' The RxFlowControl component defines whether the LFB is performing flow contron 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 classify the data packets into various network layer data packets according to information included in the Ethernet packets headers. Input of the LFB expects all types of Ethernet packets, including VLAN Ethernet types. The input is a singleton input which may connect to an upstream LFB like EtherMACIn LFB. The 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. Input of this LFB is capable of handling this case. Usually, every input Ethernet packet is expected to be associated with a PHYPortID metadatum, indicating the physical port the packet comes from. In some cases, for instance, like in an MACinMAC case, a LogicalPortID metadatum 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. A VLANInputTable component is defined in the LFB to classify VLAN Ethernet packets. 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. Therefore the table actually applies to every input packet of the LFB. The table assigns every input packet with a new Wang, et al. Expires December 4, 2011 [Page 40] Internet-Draft ForCES LFB Library June 2011 LogicalPortID according to the packet incoming port ID and the VLAN ID. A packet incoming port ID is defined as a physical port ID if there is no logical port ID associated with the packet, or a logical port ID if there is a logical port ID associated with the packet. The VLAN ID is exactly the Vlan ID in the packet if it is a VLAN packet, or 0 if it is not a VLAN packet. Note that a logical port ID of a packet may be rewritten with a new one by the VLANInputTable processing. An EtherDispatchTable component is defined to dispatch every Ethernet packet to a group of outputs according to the logical port ID assigned by VLANInputTable to the packet and the Ethernet type in the Ethernet packet header. By CE configuring the dispatch table, the LFB can be expected to classify various network layer protocol type packets and make them output at different output port. It is then easily expected that the LFB classify packets according to protocols like IPv4, IPv6, MPLS, ARP, ND, etc. Output of the LFB is hence defined as a group output. Because there may be various types of protocol packets at the output ports, the frameproduced is defined as arbitrary for the purpose of wide extensibility in the future. In order for downstream LFBs to use, a bunch of metadata is produced to associate with every output packet. The medatdata contain normal information like PHYPortID. It also contains information on Ethernet type, source MAC address, and destination MAC address of its original Ethernet packet. Moreover, it contains information of logical port ID assigned by this LFB. This metadata may be used by downstream LFBs for packet processing. Lastly, it may conditionally contain information like VlanID and VlanPriority with the condition that the packet is a VLAN packet. A MaxOutPutPorts is defined as the capability of the LFB to indicate how many classification output ports the LFB is capable. /*discussion*/ Note that logical port ID and physical port ID mentioned above are all originally configured by CE, and are globally effective within an 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. /*discussion */ There are also some other components, capabilities, events defined in the LFB for various purposes. See section 6 for detailed XML definitions of the LFB. Wang, et al. Expires December 4, 2011 [Page 41] Internet-Draft ForCES LFB Library June 2011 5.1.4. EtherEncapsulator EtherEncapsulator LFB abstracts the process to encapsulate IP packets to Ethernet packets. Input of the LFB expects types of IP packets, including IPv4 and IPv6 types. The input is a singleton one which may connect to an upstream LFB like an IPv4NextHop, an IPv6NextHop, or any LFB which requires to output packets for Ethernet encapsulation. The input is capable of multiplexing to allow for multiple upstream LFBs being connected. For instance, an IPv4NextHop or an IPv6NextHop may concurrently exist, and some L2 bridging LFBs may also output packets to this LFB simultaneously. Input of this LFB is capable of handling this case. Usually, every input Ethernet packet is expected to be associated with an output logical port ID and a next hop IP address as its metadata. In the case when L2 bridging function is implemented, an input packet may also optionally receive a VLAN priority as its metadata. In this case, default value for this metadata is set to 0. There are several outputs for this LFB. One singleton output is for normal success packet output. Packets which have found Ethernet L2 information and have been successfully encapsulated to an Ethernet packet will output from this port to downstream LFB. Note that this LFB specifies to use Ethernet II as its Ethernet encapsulation type. Success output also produces an output logical port ID as metadatum of every output packet for a downstream LFB to decide which logical port the packet should go out. The downstream LFB usually dispatches the packets based on its associated output logical port ID. Hence, a generic dispatch LFB as defined in Section 5.6.1 may be adopted for dispatching packets based on output logical port ID. Note that in some implementations of LFBs topology, the processing to dispatch packets based on an output logical port ID may also take place before an Ethernet encapsulation,i.e., packets coming into the encapsulator LFB have already been switched to individual logical output port paths. In this case, the EtherEncap LFB success output may be directly connected to a downstream LFB like an EtherMACOut LFB. Another singleton output is for IPv4 packets that are unfortunately unable to find Ethernet L2 encapsulation information by ARP table in the LFB. In this case, a copy of the packets may need to be redirected to an ARP LFB in the FE, or to CE if ARP function is implemented by CE. More importantly, a next hop IP address metadata should be associated with every packet output here. When an ARP LFB or CE receives these packets and associated next hop IP address metadata, it may be expected to generate ARP protocol messages based on these packets next hop IP addresses to try to get L2 information Wang, et al. Expires December 4, 2011 [Page 42] Internet-Draft ForCES LFB Library June 2011 for these packets. Refreshed L2 information is then able to be added in ARP table in this encapsulator LFB by ARP LFB or by CE. As a result, these packets are then able to successfully find L2 information and be encapsulated to Ethernet packets, and output via the normal success output to downstream LFB. (Editorial note1: may need discussion on what more metadata this output packets need? Note that the packets may be redirected to CE and CE should know what the purpose of the packets for. A metadata may need to indicate this. Editorial note2: we may adopt another way to address the case of packets unable to do ARP. The packets may be redirected to ARP LFB or CE without keeping a copy of them in this encapsulator LFB. We expect that after ARP LFB or CE have processed ARP requests based on the packets, the packets will be redirected back from ARP LFB or CE to this encapsulator LFB for Ethernet encapsulation. At this time, it is hoped the ARP table has been refreshed with new L2 information that will make these packets able to find) A more singleton output is for IPv6 packets that are unfortunately unable to find Ethernet L2 encapsulation information by Neighbor table in the LFB. In this case, a copy of the packets may need to be redirected to an ND LFB in the FE, or to CE if IPv6 Neighbor discovery function is implemented by CE. More importantly, a next hop IP address metadata should be associated with every packet output here. When the ND LFB or CE receives these packets and associated next hop IP address metadata, it may be expected to generate neighbor discovery protocol messages based on these packets next hop IP addresses to try to get L2 information for these packets. Refreshed L2 information is then able to be added in neighbor table in this LFB by ND LFB or by CE. As a result, these packets are then able to successfully find L2 information and be encapsulated to Ethernet packets, and output via the normal success output to downstream LFB.(Editorial note: may need discussion on what more metadata this output packets need? Note that the packets may be redirected to CE and CE should know what the purpose of the packets for. A metadata may need to indicate this) A singleton output is specifically defined for exception packets output. All packets that are abnormal during the operations in this LFB are output via this port. Currently, only one abnormal case is defined, that is, packets can not find proper information in a VLAN output table. The VLAN output table is defined as the component of the LFB. The table uses a logical port ID as an index to find a VLAN ID and a new output logical port ID. In reality, the logical port ID applied here is the output logical port ID received from every input packet in its associated metadata. According to IEEE VLAN specifications, all Ethernet packets can be recognized as VLAN types by defining that if Wang, et al. Expires December 4, 2011 [Page 43] Internet-Draft ForCES LFB Library June 2011 there is no VLAN encapsulation in a packet, a case with VLAN tag 0 is considered. Therefore, every input IP packet actually has to look up the VLAN output table to find out a VLAN ID and a new output logical port ID according to its original logical port ID.. The ARP table in the LFB is defined as a component of the LFB. The table is for IPv4 packet to find its next hop Ethernet layer MAC addresses. Input IPv4 packet will use an output logical port ID which is got by looking up the VLAN output table, and a next hop IPv4 address which is got by upstream next hop applicator LFB, to look up the ARP table to find the Ethernet L2 information, i.e., the source MAC address and destination MAC address. The neighbor table is defined as another component of the LFB. The table is for IPv6 packet to find its next hop Ethernet layer MAC addresses. Like the ARP table, input IPv6 packet will use its output logical port ID got from looking up the VLAN output table, and the packet next hop IPv4 address got by upstream next hop applicator LFB, to look up the neighbor table to find the Ethernet source MAC address and destination MAC address. As will be described in the address resolution LFBs section (section 5.4), Layer 2 address resolution protocols may be implemented with two choices. One is by FE with specific address resolution LFB, like an ARP LFB or an ND LFB. The other is to redirect address resolution protocol messages to CE for CE to implement the function. As described in section 5.4, the ARP LFB defines the ARP table in this encapsulator LFB as its alias, and the ND LFB defines the neighbor table as its alias. This means that the ARP table or the neighbor table will be maintained or refreshed by the ARP LFB or the ND LFB when the LFBs are used. Note that the ARP table and the neighbor table defined in this LFB are all with property of read-write. CE can also configure the tables by ForCES protocol [RFC5810]. This makes possible that IPv4 ARP protocol or IPv6 Neighbor Discovery protocol may be implemented at CE side,i.e., after CE manages an ARP or Neighbor discovery protocol and gets address resolution results, CE can configure them to an ARP or neighbor table in FE. With all the information got from VLAN table and ARP or Neighbor table, input IPv4 or IPv6 packets are then able to be encapsulated to Ethernet layer packets. Note that according to IEEE 802.1Q, if input packets are with non-zero VLAN priority metadata, the packets will always be encapsulated with a VLAN tag, no matter the value of VLAN ID is zero or not. If the VLAN priority and the VLAN ID are all zero, the packets will be encapsulated without a VLAN tag. Wang, et al. Expires December 4, 2011 [Page 44] Internet-Draft ForCES LFB Library June 2011 Successfully encapsulated packets are then output via success output port. There are also some other components, capabilities, events defined in the LFB for various purposes. See section 6 for detailed XML definitions of the LFB. 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 metadatum indicating the physical port ID that the packet will go through(editorial note: need more discussion on the port ID being physical layer or L2 layer). The LFB is defined with a singleton output. All Output packets are in Ethernet format, possibly with various Ethernet types, alongside with a metadatum 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 can perform Ethernet layer flow control. This is usually implemented cooperatively by the EtherMACIn LFB and the EtherMACOut LFB. The flow control is further distinguished by Tx flow control and Rx flow control, separately for sending process and receiving process flow control. 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 Wang, et al. Expires December 4, 2011 [Page 45] Internet-Draft ForCES LFB Library June 2011 LFB, both of which share the same administrative status management by CE. Alias properties as defined in the ForCES FE model (RFC 5812) will be used by CE to declare the target component this alias refers, which include the target LFB class and instance IDs as well as the path to the target component. Whereas, these properties are set by CE only when a system runs, which are outside the XML definitions of this LFB. 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 RFC 1812. 5.2.1.1. Data Handling This LFB performs IPv4 validation according to RFC 1812. Then the IPv4 packet will be output to the corresponding port regarding of the validation result, whether the packet is a unicast or a multicast Wang, et al. Expires December 4, 2011 [Page 46] Internet-Draft ForCES LFB Library June 2011 one, 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. Note that, as a default provision of RFC 5812, 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 this LFB, even there is no specific metadata expected, metadata like PHYPortID produced by some upstream physical layer LFBs will always pass through this LFB. In some cases, if some component in the LFB may use the metadata, it actually still can use it regardless of whether the metadata has been expected or not. Four output ports are defined to output various validation results. 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. There is no metadata specifically required to produce at these output ports. A singleton port known as "ExceptionOut" is defined to output packets which have been validated as exception packets. An exception ID metadatum is produced to indicate what has caused the exception. Currently defined exception types include: o Packet with destination address equal to 255.255.255.255 o Packet with expired TTL o Packet with header length more than 5 words o Packet IP head including Router Alert options Note that, although TTL is checked in this LFB for validity, operations to TTL like TTL decreasing will be made only in a followed forwarding LFB. The final singleton port known as "FailOut" is defined for all packets which have failed the validation process. A validate error ID is associated to every failed packet to indicate the reason. Currently defined reasons include: Wang, et al. Expires December 4, 2011 [Page 47] Internet-Draft ForCES LFB Library June 2011 o Packet size reported is less than 20 bytes o Packet with version is not IPv4 o Packet with header length < 5 o Packet with total length field < 20 o Packet with invalid checksum o Packet with source address equal to 255.255.255.255 o Packet with source address 0 o Packet with source address of form {127, } o Packet with source address in Class E domain 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 RFC 2460. 5.2.2.1. Data Handling This LFB performs IPv6 validation according to RFC 2460. 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. Wang, et al. Expires December 4, 2011 [Page 48] Internet-Draft ForCES LFB Library June 2011 There is no specific metadata expected by the input of the LFB. Similar to the IPv4validator LFB, IPv6Validator has also defined four output ports to output packets for 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 specifically required to produce at these output ports. 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 caused the exception. Currently defined exception types include: o Packet with hop limit to zero o Packet with a link-local destination address o Packet with a link-local source address o Packet with destination all-routers o Packet with destination all-nodes o Packet with next header set to Hop-by-Hop The final singleton port known as "FailOut" is defined for all packets which have failed the validation process. A validate error ID is associated to every failed packet to indicate the reason. Currently defined reasons include: o Packet size reported is less than 40 bytes o Packet with version is not IPv6 o Packet with multicast source address (the MSB of the source address is 0xFF) o Packet with destination address set to 0 or ::1 o Packet with source address set to loopback (::1). 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. Wang, et al. Expires December 4, 2011 [Page 49] Internet-Draft ForCES LFB Library June 2011 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 document restricts its LFB definition scope for IP forwarding jobs only to IP unicast forwarding. LFBs for jobs like IP multicast may be defined in future versions of the document. A typical IP unicast forwarding job is usually realized by looking up some forwarding information table to find some next hop information, and then based on the next hop information, forwarding packets to specific 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 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 FE to translate attributes defined by this document into real attributes the implementation has actually applied. 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. Wang, et al. Expires December 4, 2011 [Page 50] Internet-Draft ForCES LFB Library June 2011 5.3.1. IPv4UcastLPM The LFB abstracts the process for IPv4 unicast LPM table looking up. Input of the LFB always expects to receive IPv4 unicast packets. An IPv4 prefix table is defined as a component for the LFB to provide forwarding information for every input packet. The destination IPv4 address of every packet is as the index to look up the table with the rule of longest prefix matching(LPM). A hop selector is the matching result, which will be output to downstream LFBs as an index for next hop information. Normal output of the LFB is a singleton output, which will output IPv4 unicast packet that has passed the LPM lookup and got a hop selector as the lookup result. The hop selector is associated with the packet as a metadatum. Followed the normal output of the LPM LFB is usually a next hop applicator LFB. The LFB receives packets with their next hop IDs and based on the next hop IDs to forward the packets. A hop selector associated with every packet from the normal output will directly act as a next hop ID for a next hop applicator LFB.. The LFB is defined to provide some 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 implement ECMP or RPF, additional specific LFBs, like a specific ECMP LFB, will have to be defined. This work may be done in the future version of the document. For the LFB to support ECMP, an ECMP flag is defined in the prefix table entries. When the flag is set to true, it indicates this table entry is for ECMP only. In this case, the hop selector in this table entry will be used as an index for a downstream specific ECMP LFB to find its correspondent next hop IDs. When ECMP is applied, it will usually get multiple next hops information. To distinguish normal output from ECMP case output, a specific ECMP output is defined. A packet, which has passed through prefix table entry lookup with true ECMP flag, will always output from this port, with the hop selector being its lookup result. The output will usually directly go to a downstream ECMP processing LFB. In the ECMP LFB, based on the hop selector, multiple next hop IDs may be found, and more ECMP algorithms may be applied to optimize the route. As the result of the ECMP LFB, it will output optimized one or multiple next hop IDs to its downstream LFB that is usually a next hop applicator LFB. For the LFB to support RPF, a default route flag is defined in the Wang, et al. Expires December 4, 2011 [Page 51] Internet-Draft ForCES LFB Library June 2011 prefix table entry. When set true, the prefix entry is identified as a default route, and also as a forbidden route for RPF. To implement various RPF, one or more specific LFBs have to be defined. This job may be done for the future version of the library. An exception output is defined to allow some exceptional packets to output here. Exceptions include cases like packets can not find any routes by the prefix table. There are also some other components defined in the LFB for various purposes. See section 6 for detailed XML definitions of the LFB. 5.3.2. IPv4NextHop This LFB abstracts the process of next hop information application to IPv4 packets. The LFB receives an IPv4 packet with an associated next hop ID, and uses the ID to look up a next hop table to find an appropriate output port from the LFB. Simultaneously, the LFB also implements TTL operation and checksum recalculation of every IPv4 packet received. Input of the LFB is a singleton one which expects to receive IPv4 unicast packets and hop selector metadata from an upstream LFB. Usually, the upstream LFB is directly an IPv4UnicastLPM LFB_while it is possible some other upstream LFB may be applied. For instance, when ECMP is supported, the upstream LFB may be some specific ECMP LFB. The next hop ID in hop selector metadata of a packet is then used as an index to look up a next hop table defined in the LFB. Via this table and the next hop index, important information for forwarding the packet is found. Every next hop table entry includes the following information: output logical port ID, which will be used by downstream LFBs to find proper output port. next hop option, which decides if packets with next hop of this table entry are destinated to locally attached hosts or not. Locally attached hosts are hosts in the same subnet with this router. Next hop option is marked as 'forwarded to locally attached host' if the next hop entry is for locally attached hosts delivery. All other next hop entry will be marked with 'normal forwarding'. If a data packet passes through next hop entries with its next hop option marked with forwarded to locally attached host, the next hop IP address metadata associated with the data packet when output from the LFB will be forced to set to the Wang, et al. Expires December 4, 2011 [Page 52] Internet-Draft ForCES LFB Library June 2011 destination IP address of the data packet. If a data packet passes through a next hop entry with its option being normal forwarding, the next hop IP address metadata at output will be set to the next hop IP address as indicated by this next hop entry. Advantage to define this next hop option for locally attached hosts is, in this way, the next hop entry number may be greatly reduced in the case there are a vast number of locally attached hosts. next hop IP address, which will be used by downstream LFB to find proper output port IP address for this packet. Note that when next hop option is set to 'forwarded to locally attached host', this entry field becomes invalid. In this case the next hop IP address is assigned directly by destination IP address of the data packet pass through this entry check. encapsulation output index, which is used by data packet to find proper output of this LFB. Usually, this index can be used to indicate which encapsulation followed the LFB may be applied to data packets pass through this next hop entry check and to classify the packets to different instance of a group output port. Moreover, this index can also be used to purely indicate output port instance to act as a classifier based on next hop IDs. For instance, a next hop table entry can be defined with its encapsulation output index being directed to an output port which is followed with LFBs that will redirect data packets to Control Element(CE). A next hop entry can also be defined for some data packets that need special local processing of the Forwarding Element(FE). In this case it is not really acting as an encapsulation index, rather a pure output index. As a result, the LFB is defined with two output ports. One is for success output and another is for exception output. Success output is a group output, with an index to indicate which output instance in the group is adopted. The index is exactly the encapsulation output index described above. Downstream LFBs connected to the success output group may be various LFBs for encapsulation like LFBs for Ethernet encapsulation and for PPP encapsulation, various LFBs for local processing, and LFBs for redirecting packets to CE for processing. Next hop table uses the encapsulation output index to indicate which port instance in the output group a packet should go. Every port instance of the success output group will produce metadata of output logical port ID and next hop IP address for every output packet. These metadata will be used by downstream LFBs to further implementing forwarding or local processing. Note that for next hop option marked as local host processing, the next hop IP address metadata for the packet is exactly substituted with the destination Wang, et al. Expires December 4, 2011 [Page 53] Internet-Draft ForCES LFB Library June 2011 IP address of the packet. The exception output of the LFB is a singleton output. It outputs packets with exceptional cases. An exception ID further indicates the exception reasons. Exception may happen when a hop selector is found invalid, or ICMP packets need to be generated (Editorial note: more discussions here), etc. The exception ID is also produced as a metadata by the output to be transmitted to a downstream LFB. There are also some other components defined in the LFB for various purposes. See section 6 for detailed XML definitions of the LFB. 5.3.3. IPv6UcastLPM The LFB abstracts the process for IPv6 unicast LPM table looking up. Definitions of this IPv6UcastLPM LFB is very identical to IPv4UcastLPM LFB except that all IP addresses related are changed from IPv4 addresses to IPv6 addresses. See section 6 for detailed XML definitions of this LFB. 5.3.4. IPv6NextHop This LFB abstracts the process of next hop information application to IPv6 packets. Definitions of this IPv6NextHop LFB is very identical to IPv4NextHop LFB except that all IP addresses related are changed from IPv4 addresses to IPv6 addresses. See section 6 for detailed XML definitions of this LFB. 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 RFC 5810 [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 A RedirectIn LFB abstracts the process for CE to inject data packets into FE LFB topology so as to input data packets into FE data paths. Wang, et al. Expires December 4, 2011 [Page 54] Internet-Draft ForCES LFB Library June 2011 From LFB topology point of view, the RedirectIn LFB acts as a source point for data packets coming from CE, therefore the RedirectIn LFB is defined with only one output, while without any input. Output of the RedirectIn LFB is defined as a group output. Packets produced by the output will have arbitrary frame types decided by CE which generates the packets. Possible frames may include IPv4, IPv6, or ARP protocol packets. CE may associate some metadata to indicate the frame types. CE may also associate other metadata to data packets to indicate various information on the packets. Among them, there MUST exist a 'RedirectIndex' metadata, which is an integer acting as an index. When CE transmits the metadata and a binging packet to a RedirectIn LFB, the LFB will read the metadata and output the packet to one of its group output port instance, whose port index is just as indicated by the metadata. Detailed XML definition of the metadata is in the XML for base type library as in Section 4.4. All metadata from CE other than the 'RedirectIndex' metadata will output from the RedirectIn LFB along with their binding packets. Note that, a packet without a 'RedirectIndex' metadata associated will be dropped by the LFB. There is no component defined for current version of RedirectIn LFB. Detailed XML definitions of the LFB can be found in Section 6. 5.4.2. RedirectOut A RedirectOut LFB abstracts the process for LFBs in FE to deliver data packets to CE. From LFB topology point of view, the RedirectOut LFB acts as a sink point for data packets going to CE, therefore the RedirectOut LFB is defined with only one input, while without any output. Input of the RedirectOut LFB is defined as a singleton input, but it is capable of receiving packets from multiple LFBs by multiplexing the singleton input. Packets expected by the input will have arbitrary frame types. All metadata associated with the input packets will be delivered to CE via a ForCES protocol redirect message [RFC5810]. The input will expect all types of metadata. There is no component defined for current version of RedirectOut LFB. Detailed XML definitions of the LFB can be found in Section 6. 5.5. General Purpose LFBs Wang, et al. Expires December 4, 2011 [Page 55] Internet-Draft ForCES LFB Library June 2011 5.5.1. BasicMetadataDispatch A basic medatata dispatch LFB is defined to abstract a process in which a packet is dispatched to some path based on its associated metadata value. The LFB is with a singleton input. Packets of arbitrary frame types can input into the LFB. Whereas, every input packet is required to be associated with a metadata that will be used by the LFB to do dispatch. If a packet is not associated with such metadata, the packet will be dropped inside the LFB. A group of output is defined to output packets according to a MetaDispatchTable as defined a component in the LFB. The table contains the fields of a metadata ID, a metadata value, and an output port index. A packet, if it is associated with a metadata with the metadata ID, will be output to the group port instance with the index corresponding to the metadata value in the table. The metadata value ussed by the table is required with an interger data type. This means this LFB currently only allow a metadata with an interger value to be used for dispatch. Moreover, the LFB is defined with only one metadata adopted for dispatch, i.e., the metadata ID in the dispatch table is always the same for all table rows. A more complex metadata dispatch LFB may be defined in future version of the library. In that LFB, multiple tuples of metadata may be adopted to dispatch packets. 5.5.2. GenericScheduler 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. The generic scheduler LFB is the one. Users may use this LFB as a basic scheduler LFB to further construct more complex scheduler LFBs by means of inheritance as described in RFC 5812 [RFC5812]. The LFB describes scheduling process in the following model: o It is with a group input and expects packets with arbitrary frame types to arrive for scheduling. The group input is capable of multiple input port instances. Each port instance may be connected to different upstream LFB output. No metadata is expected for each input packet. Wang, et al. Expires December 4, 2011 [Page 56] Internet-Draft ForCES LFB Library June 2011 o Multiple queues reside at the input side, with every input port instance connected to one queue. o Every queue is marked with a queue ID, and the queue ID is exactly the same as the index of corresponding input port instance. o Scheduling disciplines are applied to all queues and also all packets in the queues. o Scheduled packets are output from a singleton output port of the LFB. Two LFB components are defined to further describe above model. A scheduling discipline component is defined for CE to specify a scheduling discipline to the LFB. Currently defined scheduling disciplines only include FIFO and round robin(RR). For FIFO, we limit above model that when a FIFO discipline is applied, it is require that there is only one input port instance for the group input. If user accidentally defines multiple input port instances for FIFO scheduling, only packets in the input port with lowest port index will be scheduled to output port, and all packets in other input port instances will just ignored. We specify that if the generic scheduler LFB is defined only one input port instance, the default scheduling discipline is FIFO. If the LFB is defined with more than one input port instances, the default scheduling discipline is round robin (RR). A current queue depth component is defined to allow CE to query every queue status of the scheduler. Using the queue ID as the index, CE can query every queue for its used length in unit of packets or bytes. Several capabilities are defined for the LFB. A queue number limit is defined which limits the scheduler maximum supported queue number, which is also the maximum number of input port instances. Capability of disciplines supported provides scheduling discipline types supported by the FE to CE. Queue length limit provides the capability of storage ability for every queue. More complex scheduler LFB may be defined with more complex scheduling discipline by succeeding this LFB. For instance, a priority scheduler LFB may be defined only by inheriting this LFB and define a component to indicate priorities for all input queues. See Section 6 for detailed XML definition for this LFB. Wang, et al. Expires December 4, 2011 [Page 57] Internet-Draft ForCES LFB Library June 2011 6. XML for LFB Library EtherPHYCop The LFB describes an Ethernet port abstracted at physical layer.It limits its physical media to copper. Multiple virtual PHYs isn't supported in this LFB version. 1.0 EtherPHYIn The input port of the EtherPHYCop LFB. It expects any kind of Ethernet frame. EthernetAll EtherPHYOut The output port of the EtherPHYCop LFB. It can produce any kind of Ethernet frame and along with the frame passes the ID of the Physical Port as metadata to be used by the next LFBs. EthernetAll PHYPortID PHYPortID The ID of the physical port that this LFB Wang, et al. Expires December 4, 2011 [Page 58] Internet-Draft ForCES LFB Library June 2011 handles. uint32 AdminStatus Admin status of the LFB PortStatusValues 2 OperStatus Operational status of the LFB. PortStatusValues AdminLinkSpeed The link speed that the admin has requested. LANSpeedType 0x00000005 OperLinkSpeed The actual operational link speed. LANSpeedType AdminDuplexMode The duplex mode that the admin has requested. DuplexType 0x00000001 OperDuplexMode The actual duplex mode. DuplexType CarrierStatus The status of the Carrier. Whether the port is linked with an operational connector. boolean false Wang, et al. Expires December 4, 2011 [Page 59] Internet-Draft ForCES LFB Library June 2011 SupportedLinkSpeed Supported Link Speeds LANSpeedType SupportedDuplexMode Supported Duplex Modes DuplexType PHYPortStatusChanged When the status of the Physical port is changed,the LFB sends the new status. OperStatus OperStatus LinkSpeedChanged When the operational speed of the link is changed, the LFB sends the new operational link speed. OperLinkSpeed OperLinkSpeed DuplexModeChanged When the operational duplex mode is changed, the LFB sends the new operational mode. Wang, et al. Expires December 4, 2011 [Page 60] Internet-Draft ForCES LFB Library June 2011 OperDuplexMode OperDuplexMode EtherMACIn An LFB abstracts an Ethernet port at MAC data link layer. It specifically describes Ethernet processing functions like MAC address locality check, deciding if the Ethernet packets should be bridged, provide Ethernet layer flow control, etc.Multiple virtual MACs isn't supported in this LFB version. 1.0 EtherMACIn The input port of the EtherMACIn. It expects any kind of Ethernet frame. EthernetAll PHYPortID NormalPathOut The normal output port of the EtherMACIn. It can produce any kind of Ethernet frame and along with the frame passes the ID of the Physical Port as metadata to be used by the next LFBs. EthernetAll Wang, et al. Expires December 4, 2011 [Page 61] Internet-Draft ForCES LFB Library June 2011 PHYPortID L2BridgingPathOut The Bridging Output Port of the EtherMACIn. It can produce any kind of Ethernet frame and along with the frame passes the ID of the Physical Port as metadata to be used by the next LFBs. EthernetAll PHYPortID AdminStatus Admin status of the port PortStatusValues 2 LocalMACAddresses Local Mac addresses IEEEMAC L2BridgingPathEnable Is the LFB doing L2 Bridging? boolean false PromiscuousMode Is the LFB in Promiscuous Mode? boolean false Wang, et al. Expires December 4, 2011 [Page 62] Internet-Draft ForCES LFB Library June 2011 TxFlowControl Transmit flow control boolean false RxFlowControl Receive flow control boolean false MACInStats MACIn statistics MACInStatsType EtherClassifier This LFB abstracts the process to decapsulate Ethernet packets and classify the data packets into various network layer data packets according to information included in the Ethernet packets headers. 1.0 EtherPktsIn Input port for data packet. EthernetAll PHYPortID LogicalPortID ClassifyOut Output port for classification. Arbitrary Wang, et al. Expires December 4, 2011 [Page 63] Internet-Draft ForCES LFB Library June 2011 PHYPortID SrcMAC DstMAC EtherType VlanID VlanPriority EtherDispatchTable Ether classify dispatch table EtherDispatchTableType VlanInputTable Vlan input table VlanInputTableType EtherClassifyStats Ether classify statistic table EtherClassifyStatsTableType EtherEncapsulator This LFB abstracts the process to encapsulate IP packets to Ethernet packets according to the L2 information. 1.0 EncapIn A Single Packet Input IPv4 IPv6 MediaEncapInfoIndex Wang, et al. Expires December 4, 2011 [Page 64] Internet-Draft ForCES LFB Library June 2011 VlanPriority SuccessOut Output port for Packets which have found Ethernet L2 information and have been successfully encapsulated to an Ethernet packet. IPv4 IPv6 L2PortID ExceptionOut All packets that fail with the other operations in this LFB are output via this port. IPv4 IPv6 ExceptionID MediaEncapInfoIndex VlanPriority EncapTable Ethernet Encapsulation table. EncapTableType Wang, et al. Expires December 4, 2011 [Page 65] Internet-Draft ForCES LFB Library June 2011 EtherMACOut EtherMACOut LFB abstracts an Ethernet port at MAC data link layer. It specifically describes Ethernet packet output process. Ethernet output functions are closely related to Ethernet input functions, therefore some components defined in this LFB are actually alias of EtherMACIn LFB. 1.0 EtherPktsIn The Input Port of the EtherMACIn. It expects any kind of Ethernet frame. EthernetAll PHYPortID EtherMACOut The Normal Output Port of the EtherMACOut. It can produce any kind of Ethernet frame and along with the frame passes the ID of the Physical Port as metadata to be used by the next LFBs. EthernetAll PHYPortID AdminStatus Admin status of the port. It is the alias of "AdminStatus" component defined in EtherMACIn. PortStatusValues Wang, et al. Expires December 4, 2011 [Page 66] Internet-Draft ForCES LFB Library June 2011 MTU Maximum transmission unit. uint32 TxFlowControl Transmit flow control. It is the alias of "TxFlowControl" component defined in EtherMACIn. boolean RxFlowControl Receive flow control. It is the alias of "RxFlowControl" component defined in EtherMACIn. boolean MACOutStats MACOut statistics MACOutStatsType IPv4Validator An LFB that performs IPv4 packets validation according to RFC1812. At the same time, ipv4 unicast and multicast are classified in this LFB. 1.0 ValidatePktsIn Input port for data packet. Arbitrary IPv4UnicastOut Output for IPv4 unicast packet. Wang, et al. Expires December 4, 2011 [Page 67] Internet-Draft ForCES LFB Library June 2011 IPv4Unicast IPv4MulticastOut Output for IPv4 multicast packet. IPv4Multicast ExceptionOut Output for exception packet. IPv4 ExceptionID FailOut Output for failed validation packet. IPv4 ValidateErrorID IPv4ValidatorStats IPv4 validator statistics information. IPv4ValidatorStatisticsType Wang, et al. Expires December 4, 2011 [Page 68] Internet-Draft ForCES LFB Library June 2011 IPv6Validator An LFB that performs IPv6 packets validation according to RFC2460. At the same time, ipv6 unicast and multicast are classified in this LFB. 1.0 ValidatePktsIn Input port for data packet. Arbitrary IPv6UnicastOut Output for IPv6 unicast packet. IPv6Unicast IPv6MulticastOut Output for IPv6 multicast packet. IPv6Multicast ExceptionOut Output for exception packet. IPv6 ExceptionID Wang, et al. Expires December 4, 2011 [Page 69] Internet-Draft ForCES LFB Library June 2011 FailOut Output for failed validation packet. IPv6 ValidateErrorID IPv6ValidatorStats IPv6 validator statistics information. IPv6ValidatorStatisticsType IPv4UcastLPM An LFB that performs IPv4 Longest Prefix Match Lookup.It is defined to provide some facilities to support users to implement equal-cost multi-path routing(ECMP) or reverse path forwarding (RPF). 1.0 PktsIn A Single Packet Input IPv4Unicast NormalOut This output port is connected with IPv4NextHop LFB Wang, et al. Expires December 4, 2011 [Page 70] Internet-Draft ForCES LFB Library June 2011 IPv4Unicast HopSelector ECMPOut This output port is connected with ECMP LFB, if there is ECMP LFB in the FE. IPv4Unicast HopSelector ExceptionOut The output for the packet if an exception occurs IPv4Unicast ExceptionID IPv4PrefixTable The IPv4 prefix table. IPv4PrefixTableType IPv4UcastLPMStats Statistics for IPv4 Unicast Longest Prefix Match IPv4UcastLPMStatsType Wang, et al. Expires December 4, 2011 [Page 71] Internet-Draft ForCES LFB Library June 2011 IPv6UcastLPM An LFB that performs IPv6 Longest Prefix Match Lookup.It is defined to provide some facilities to support users to implement equal-cost multi-path routing(ECMP) or reverse path forwarding (RPF). 1.0 PktsIn A Single Packet Input IPv6Unicast NormalOut This output port is connected with IPv6NextHop LFB IPv6Unicast HopSelector ECMPOut This output port is connected with ECMP LFB, if there is ECMP LFB in the FE. IPv6Unicast HopSelector ExceptionOut Wang, et al. Expires December 4, 2011 [Page 72] Internet-Draft ForCES LFB Library June 2011 The output for the packet if an exception occurs IPv6Unicast ExceptionID IPv6PrefixTable The IPv6 prefix table. IPv6PrefixTableType IPv6UcastLPMStats Statistics for IPv6 Unicast Longest Prefix Match IPv6UcastLPMStatsType IPv4NextHop This LFB abstracts the process of selecting ipv4 next hop action. It receives an IPv4 packet with an associated next hop ID, and uses the ID to look up a next hop table to find an appropriate output port from the LFB. 1.0 PktsIn A Single Packet Input IPv4Unicast HopSelector Wang, et al. Expires December 4, 2011 [Page 73] Internet-Draft ForCES LFB Library June 2011 SuccessOut The output for the packet if it is valid to be forwarded IPv4Unicast OutputLogicalPortID NextHopIPv4Addr ExceptionOut The output for the packet if an exception occurs IPv4Unicast ExceptionID IPv4NextHopTable The next hop table. IPv4NextHopTableType IPv6NextHop The LFB abstracts the process of next hop information application to IPv6 packets. It receives an IPv4 packet with an associated next hop ID, and uses the ID to look up a next hop table to find an appropriate output port from the LFB.. 1.0 PktsIn Wang, et al. Expires December 4, 2011 [Page 74] Internet-Draft ForCES LFB Library June 2011 A single packet input. IPv6Unicast HopSelector SuccessOut The output for the packet if it is valid to be forwarded IPv6Unicast OutputLogicalPortID NextHopIPv6Addr ExceptionOut The output for the packet if an exception occurs IPv6Unicast ExceptionID IPv6NextHopTable The next hop table. IPv6NextHopTableType Wang, et al. Expires December 4, 2011 [Page 75] Internet-Draft ForCES LFB Library June 2011 RedirectIn The RedirectIn LFB abstracts the process for CE to inject data packets into FE LFB topology, so as to input data packets into FE data paths. CE may associate some metadata to data packets to indicate various information on the packets. Among them, there MUST exist a 'RedirectIndex' metadata, which is an integer acting as an output port index. 1.0 PktsOut This output group sends the redirected packet in the data path. Arbitrary RedirectOut The LFB abstracts the process for LFBs in FE to deliver data packets to CE. All metadata associated with the input packets will be delivered to CE via the redirect message of ForCES protocol [RFC5810]. 1.0 PktsIn This input receives packets to send to the CE. Arbitrary BasicMetadataDispatch This LFB provides the function to dispatch input packets to a group output according to a metadata and a Wang, et al. Expires December 4, 2011 [Page 76] Internet-Draft ForCES LFB Library June 2011 dispatch table.This LFB currently only allow a metadata with an interger value to be used for dispatch. 1.0 PktsIn Input port for data packet. Arbitrary Arbitrary PktsOut Data packet output Arbitrary MetadataDispatchTable Metadata dispatch 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 RFC 5812. 1.0 PktsIn Input port for data packet. Wang, et al. Expires December 4, 2011 [Page 77] Internet-Draft ForCES LFB Library June 2011 Arbitrary PktsOut Data packet output. Arbitrary QueueCount The number of queues to be scheduled. uint32 SchedulingDiscipline the Scheduler discipline. SchdDisciplineType CurrentQueueDepth Current Depth of all queues QueueDepthTableType QueueLenLimit Maximum length of each queue,the unit is byte. uint32 QueueScheduledLimit Max number of queues that can be scheduled by this scheduluer. uint32 Wang, et al. Expires December 4, 2011 [Page 78] Internet-Draft ForCES LFB Library June 2011 DisciplinesSupported the scheduling disciplines supported. SchdDisciplineType Wang, et al. Expires December 4, 2011 [Page 79] Internet-Draft ForCES LFB Library June 2011 7. LFB Class Use Cases This section demonstrates examples on how the LFB classes defined by the Base LFB library in Section 6 are applied to achieve typical router functions. As mentioned in the overview section, typical router functions can be categorized in short into the following functions: o IP forwarding o address resolution o ICMP o network management o running routing protocol To achieve the functions, processing paths organized by the LFB classes with their interconnections should be established in FE. In general, CE controls and manages the processing paths by use of the ForCES protocol. Note that LFB class use cases shown in this section are only as examples to demonstrate how typical router functions can be implemented with the defined base LFB library. Users and implementers should not be limited by the examples. 7.1. IP Forwarding TBD Wang, et al. Expires December 4, 2011 [Page 80] Internet-Draft ForCES LFB Library June 2011 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 December 4, 2011 [Page 81] Internet-Draft ForCES LFB Library June 2011 9. Acknowledgements This document is based on earlier documents from Joel Halpern, Ligang Dong, Fenggen Jia and Weiming Wang. Wang, et al. Expires December 4, 2011 [Page 82] Internet-Draft ForCES LFB Library June 2011 10. IANA Considerations (TBD) Wang, et al. Expires December 4, 2011 [Page 83] Internet-Draft ForCES LFB Library June 2011 11. Security Considerations These definitions if used by an FE to support ForCES create manipulable entities on the FE. Manipulation of such objects can produce almost unlimited effects on the FE. FEs should ensure that only properly authenticated ForCES protocol participants are performing such manipulations. Thus the security issues with this protocol are defined in the ForCES protocol [RFC5810]. Wang, et al. Expires December 4, 2011 [Page 84] Internet-Draft ForCES LFB Library June 2011 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 [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. [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 December 4, 2011 [Page 85] Internet-Draft ForCES LFB Library June 2011 Authors' Addresses Weiming Wang Zhejiang Gongshang University 18 Xuezheng Str., Xiasha University Town Hangzhou, 310018 P.R.China Phone: +86-571-28877721 Email: wmwang@zjgsu.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 BAUD Networks 408 Wen-San Road Hangzhou, 310012 P.R.China Phone: +86-571-28877751 Email: chuanhuang_li@zjgsu.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 December 4, 2011 [Page 86]