Internet Engineering Task Force W. Wang Internet-Draft Zhejiang Gongshang University Intended status: Informational E. Haleplidis Expires: September 4, 2010 University of Patras K. Ogawa NTT Corporation F. Jia National Digital Switching Center(NDSC) J. Halpern Ericsson March 3, 2010 ForCES LFB Library draft-ietf-forces-lfb-lib-01 Abstract The forwarding and Control Element Separation (ForCES) protocol defines a standard communication and control mechanism through which a Control Element (CE) can control the behavior of a Forwarding Element (FE). That control is accomplished through manipulating components of Logical Function Blocks (LFBs), whose structure is defined in a model RFC produced by the working group.In order to build an actual solution using this protocol, there needs to be a set of Logical Function Block definitions that can be instantiated by FEs and controlled by CEs. This document provides a sample space of such definitions. It is anticipated that additional defining documents will be produced over time. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. Wang, et al. Expires September 4, 2010 [Page 1] Internet-Draft ForCES LFB Library March 2010 The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on September 4, 2010. Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. 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 BSD License. Wang, et al. Expires September 4, 2010 [Page 2] Internet-Draft ForCES LFB Library March 2010 Table of Contents 1. Terminology and Conventions . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Base Types . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.1. Data Types . . . . . . . . . . . . . . . . . . . . . . . . 11 5.2. Frame Types . . . . . . . . . . . . . . . . . . . . . . . 13 5.3. MetaData Types . . . . . . . . . . . . . . . . . . . . . . 14 5.4. XML Definition for Base Type Library . . . . . . . . . . . 15 6. LFB Classes Description . . . . . . . . . . . . . . . . . . . 39 6.1. Core LFBs . . . . . . . . . . . . . . . . . . . . . . . . 39 6.1.1. FE Protocol LFB . . . . . . . . . . . . . . . . . . . 39 6.1.2. FE Object LFB . . . . . . . . . . . . . . . . . . . . 39 6.2. Port LFBs . . . . . . . . . . . . . . . . . . . . . . . . 40 6.2.1. Generic Connectivity LFB . . . . . . . . . . . . . . . 40 6.2.2. Ethernet Port LFBs . . . . . . . . . . . . . . . . . . 41 6.2.3. POS Port LFBs . . . . . . . . . . . . . . . . . . . . 41 6.2.4. ATM Port LFBs . . . . . . . . . . . . . . . . . . . . 41 6.3. Address Resolution LFBs . . . . . . . . . . . . . . . . . 41 6.4. ICMP LFBs . . . . . . . . . . . . . . . . . . . . . . . . 42 6.5. IP Packet Validation LFBs . . . . . . . . . . . . . . . . 42 6.6. Classifier LFBs . . . . . . . . . . . . . . . . . . . . . 42 6.7. Forwarding LFBs . . . . . . . . . . . . . . . . . . . . . 43 6.7.1. Unicast Longest Prefix Match LFBs . . . . . . . . . . 43 6.7.2. Nexthop Applicator LFBs . . . . . . . . . . . . . . . 43 6.8. QoS Control LFBs . . . . . . . . . . . . . . . . . . . . . 43 6.8.1. Scheduler LFBs . . . . . . . . . . . . . . . . . . . . 44 6.8.2. Queue LFBs . . . . . . . . . . . . . . . . . . . . . . 45 6.9. Miscellaneous Packet Manipulation LFBs . . . . . . . . . . 45 6.10. Redirect LFB . . . . . . . . . . . . . . . . . . . . . . . 45 7. XML Definition for Base LFB Library . . . . . . . . . . . . . 46 8. Base LFB Library Use Case for Typical Router Functions . . . . 75 8.1. IP Forwardings . . . . . . . . . . . . . . . . . . . . . . 75 8.2. Address Resolution . . . . . . . . . . . . . . . . . . . . 76 8.3. ICMP . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 8.4. Running Routing Protocol . . . . . . . . . . . . . . . . . 76 8.5. Network Management . . . . . . . . . . . . . . . . . . . . 76 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 77 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 78 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 79 12. Security Considerations . . . . . . . . . . . . . . . . . . . 80 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 81 13.1. Normative References . . . . . . . . . . . . . . . . . . . 81 13.2. Informative References . . . . . . . . . . . . . . . . . . 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 82 Wang, et al. Expires September 4, 2010 [Page 3] Internet-Draft ForCES LFB Library March 2010 1. Terminology and Conventions 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Wang, et al. Expires September 4, 2010 [Page 4] Internet-Draft ForCES LFB Library March 2010 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 below 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 September 4, 2010 [Page 5] Internet-Draft ForCES LFB Library March 2010 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 September 4, 2010 [Page 6] Internet-Draft ForCES LFB Library March 2010 3. Introduction Forwarding and Control Element Separation (ForCES) defines an architectural framework and associated protocols to standardize information exchange between the control plane and the forwarding plane in a ForCES Network Element (ForCES NE). [RFC3654]has defined the ForCES requirements, and [RFC3746] has defined the ForCES framework. The ForCES protocol Protocol FE-protocol FE-protocol [I-D.ietf-forces-protocol] defines a protocol for communications between Control Elements (CEs) Forwarding Elements (FEs) and for Control Elements to manipulate resources in Forwarding Elements. Resources in Forwarding Elements are described by classes of Logical Function Blocks (LFBs). The FE model documentFE-MODEL [I-D.ietf-forces-model]. specifies the structure and abstract semantics of LFBs, and provides XML schema for the definitions of LFBs. This document comforts to the specifications of the FE modelFE-MODEL [I-D.ietf-forces-model] and specifies definitions of classes of LFBs which can be combined to provide functions of a typical router. It basically provides functions to implement IP forwarding. More definitions of LFB classes with more functions may be developed in future time and documented by IETF, and users may also develop individual LFB classes for purposes of their specific functions according to the FE modelFE-MODEL [I-D.ietf-forces-model]. Wang, et al. Expires September 4, 2010 [Page 7] Internet-Draft ForCES LFB Library March 2010 4. Overview The LFB classes described in this document are designed to provide the functions of a typical router [RFC1812] . They are expected to provide functions for a typical router to: o Interface to packet networks and implement the functions required by that network. These functions typically include: * Encapsulating and decapsulating the IP datagrams with the connected network framing (e.g., an Ethernet header and checksum), * Sending and receiving IP datagrams up to the maximum size supported by that network, this size is the network's Maximum Transmission Unit or MTU, * Translating the IP destination address into an appropriate network-level address for the connected network (e.g., an Ethernet hardware address), if needed, and. * Responding to network flow control and error indications, if any. o Conform to specific Internet protocols including the Internet Protocol (IPv4 and/or IPv6), Internet Control Message Protocol (ICMP), and others as necessary. o Receive and forwards Internet datagrams. Important issues in this process are buffer management, congestion control, and fairness. * Recognizes error conditions and generates ICMP error and information messages as required. * Drops datagrams whose time-to-live fields have reached zero. * Fragments datagrams when necessary to fit into the MTU of the next network. o Choose a next-hop destination for each IP datagram, based on the information in its routing database. o 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. Wang, et al. Expires September 4, 2010 [Page 8] Internet-Draft ForCES LFB Library March 2010 o Provide network management and system support facilities, including loading, debugging, status reporting, exception reporting and control. According to ForCES architecture, all above typical router functions should be implemented upon the concept of Logical Functional Blocks (LFBs). It is critical to classify above functional requirements into various classes of LFBs and construct a typical but also flexible enough base LFB library for various IP forwarding equipments. In the process, some principles may be applied: o if a function can be designed by either one LFB or two or more LFBs with the same cost, it will be designed by 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 as much as possible independence and leave least couples with other LFBs. The couples may be from LFB attributes definitions as well as physical implementations. o unless there is a difference in actual functionality, it should not represent the same thing in two different fashions. Or else, it may add extra burden on implementation. The document intends to meet the above typical router function requirements by defining groups of LFB classes like Core LFBs,Port LFBs,etc. For every group of LFB classes, a set of LFBs are defined for individual function purposes. Section 6(LFB Descriptions Section) describes individual LFBs in every group of LFBs in details. Based on the classes of LFBs, the typical organization of the processing path and their interconnections can be established by the CE using the ForCES protocol, so as to achieve typical router functions. Taking a typical forwarding function as an example, Port LFBs receive packets and decapsulate the IP datagrams to form IP level packets. Different port media have different manipulating requirements from CE, therefore various port LFBs for various media may have to be defined. IP packets from port LFBs are then validated before being further forwarded. A kind of valildation LFBs like IPv4 validator and/or IPv6 valildator are applied for the purpose. After validation, some packets for control purpose will be specifically processed, like ARP packets will be processed by an Address resolution LFB and ICMP packets by an ICMP LFB. To separate the control packets, a metadata classifier LFB is applied in the process. After validation process, Forwarding LFBs can then be applied. In the Forwarding LFBs, a Longest Prefix Match LFB is used to look up Wang, et al. Expires September 4, 2010 [Page 9] Internet-Draft ForCES LFB Library March 2010 the destination information in a packet, and select the next hop index to be used for sending the packet onward. A next hop applicator LFB uses the next hop index metadata to apply the proper headers to the IP packets, and direct them to the proper egress. Section 8 provides more detailed descriptions on how various typical router functions are implemented based on the defined base LFB classes. To define various LFB classes, a set of base type definitions with the data types, packet frame types, and metadata types have to be specified in advance. Section 5 (Base Types Section) provide a description on the base types used by this LFB library. In order to provide an extensive use of these base types for other LFB definitions, the base type definitions are provided by a specific xml file as a base type library which is separate from the LFB definition library. LFB classes are finally defined by XML with specifications and schema from the ForCES FE modelFE-MODEL [I-D.ietf-forces-model]. Section 6 (LFB Definitions Section) provide the complete XML definitions of the base LFB classes library. Wang, et al. Expires September 4, 2010 [Page 10] Internet-Draft ForCES LFB Library March 2010 5. Base Types The FE modelFE-MODEL [I-D.ietf-forces-model] 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 a detailed XML definitions of the base types. In order for extensive use of the base type definitions for other LFB definitions 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: 5.1. Data Types The following data types are currently defined and put in the base type library: 1. ifIndex - A Port Identifier. 2. IEEEMAC - IEEE MAC Address. 3. NetSpeedType - Network speed values. 4. IEEENegotiationType - IEEENegotiation types. 5. PortStatsType - Port statistics. 6. PortStatusValues - The possible values of status Used for both administrative and operation status. 7. LocalIpAddrType - Local IP address belonging to FE. 8. LocalIpv6AddrType - The device local IPv6 address infomation. 9. IPv4Addr - IPv4 address. Wang, et al. Expires September 4, 2010 [Page 11] Internet-Draft ForCES LFB Library March 2010 10. IPv6Addr - IPv6 address. 11. IPv4Prefix - IPv4 prefix defined by an address and a prefix length. 12. IPv4NextHopInfoType - IPv4 nexthop information,include nexthop ip address,output FE and interface etc. 13. IPv4FibEntryType - IPv4 forwarding table entry. 14. IPv4PrefixTableEntry - IPv4 prefix table entry. 15. IPv4UcastLPMStatisticsType - Statistics of IPv4UcastLPM LFB. 16. IPv4ValidatorStatisticsType - IPv4 validator LFB statistics type. 17. IPv6Prefix - IPv6 prefix defined by an address and a prefix length. 18. IPv6NextHopInfoType - IPv6 next hop information, include next hop ip address,output FE and interfac eetc. 19. IPv6PrefixTableEntry - IPv6 prefix table entry. 20. IPv6LPMClassiferStatisticsType - Statistics of IPv6 LPM ClassifierLFB. 21. IPv6ValidatorStatisticsType - IPv6 validator LFB statistics type. 22. NextHopFlagsType - Flags used to define different next hop behaviors. 23. WeightTableEntryType - Weight table for queues. 24. NbrState - IPv6 neighbour entry resolution state. 25. ArpTableEntryType - Arp Entry. 26. NbrTableEntryType - IPv6 neighbour table entry. 27. DCHostTableEntryTypev4 - Direct connected ARP table entry for IPv4. 28. DCHostTableEntryTypev6 - Direct connected ARP table entry for IPv6. Wang, et al. Expires September 4, 2010 [Page 12] Internet-Draft ForCES LFB Library March 2010 29. IPPacketType - The packet type code. 30. IPDispatchTableType - The dispatch table type. 31. MetaType - Metadata type definition. 32. MetadataClassTableType - The meta data classifying table. 33. LinkEncapType - Encapsulation type. 34. IPAddress - IP layer address. 35. ArpStateType - The arp entry state. 36. MatchTargetType - Indicator for the kind of field to be matched by this entry in a classifier. 37. MatchTargetIdentifier - Identify the specific target of a match condition. 38. MatchBitString - A bit string for use in a match condition. 39. MatchCondition - Structure for a single condition to be applied. 40. MatchConditiontType - Indicator for the kind of match condition to be applied. 41. MatchMetaDataAction - An action to set a metadata item to either a specific value or a field from the incoming meta data or packet. 42. NextHopIndex - An index used by the next hop table Typically stored in and generated as metadata by the longest-prefix-match LFB. 5.2. Frame Types According to FE modelFE-MODEL [I-D.ietf-forces-model], 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: Wang, et al. Expires September 4, 2010 [Page 13] Internet-Draft ForCES LFB Library March 2010 1. EthernetII - An Ethernet II frame type. 2. Ethernet802.3 - An Ethernet 802.3 frame type. 3. Ethernet802.2 - An Ethernet 802.2 frame type. 4. Ethernet802.2SNAP - An Ethernet 802.2 with SNAP frame. 5. IPv4Frame - An IPv4 packet. 6. IPv6Frame - An IPv6 packet. 7. TaggedFrame - A frame of any type with associated metadata. 8. MetadataFrame - Frame only contains meta data. 9. Arbitrary - Any kind of frame except Metadata Frame. 5.3. MetaData Types LFB Metadata is used to communicate per-packet state from one LFB to another. The element in the FE model is used to define a new metadata type. The following metadata types are currently defined and put in the base type library as base metadata types for the LFB library definitions: 1. NextHopID - An index into a Next Hop entry in Nexthop table. 2. ExceptionID - Exception Types. 3. IngressPort - At which interface the packet arrive. 4. EgressPort - The interface out which the packet will emmit. 5. NextHopIP - Nexthop IPv4 address. 6. NexthopIPv6 - Nexthop IPv6 address. 7. PacketLength - The length of the packet in octets. 8. IPPacketType - Type of the packet. 9. QueueID - The queue ID. 10. QueueOperationCmd - The type of operation on the queue,there are two types defined here: enqueue and dequeue. Wang, et al. Expires September 4, 2010 [Page 14] Internet-Draft ForCES LFB Library March 2010 11. SrcFEID - Source FE ID. 12. DstFEID - Destination FE ID. 13. NexthopIndex - Next hop index into the link layer address resolution table. 14. NHEncapMethod - How should the following LFBs do to encapsulate the packets. 15. ErrorId - Error Type. 5.4. XML Definition for Base Type Library This library provides base types definitions for LFB library. EthernetII an Ethernet II frame type Ethernet802.3 An Ethernet 802.3 frame type Ethernet802.2 An Ethernet 802.2 frame type Ethernet802.2SNAP An Ethernet 802.2 with SNAP frame IPv4 An IPv4 packet IPv6 An IPv6 packet Wang, et al. Expires September 4, 2010 [Page 15] Internet-Draft ForCES LFB Library March 2010 MetadataFrame Frame only contains meta data Arbitrary Any kind of frame except Metadata Frame. IEEEMAC IEEE mac. byte[6] LANSpeedType LAN speed values uint32 LAN_SPEED_10M 10M Ethernet LAN_SPEED_100M 100M Ethernet LAN_SPEED_1G 1000M Ethernet LAN_SPEED_10G 10G Ethernet LAN_SPEED_AUTO LAN speed auto NegotiationType Negotiation types Wang, et al. Expires September 4, 2010 [Page 16] Internet-Draft ForCES LFB Library March 2010 uint32 Auto Auto negotitation. Half-duplex port negotitation half duplex Full-duplex port negotitation full duplex PortStatsType port statistics InUcastPkts Number of unicast packets received uint64 InMulticastPkts Number of multicast packets received uint64 InBroadcastPkts Number of broadcast packets received uint64 InOctets number of octets received uint64 OutUcastPkts Number of unicast packets transmitted uint64 Wang, et al. Expires September 4, 2010 [Page 17] Internet-Draft ForCES LFB Library March 2010 OutMulticastPkts Number of multicast packets transmitted uint64 OutBroadcastPkts Number of broadcast packets transmitted uint64 OutOcetes Number of octets transmitted uint64 InErrorPkts Number of input error packets uint64 OutErrorPkts Number of output error packets uint64 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. Down The port is down. Wang, et al. Expires September 4, 2010 [Page 18] Internet-Draft ForCES LFB Library March 2010 IPAddr IPv4 address uint32 MacFilterTableEntryType MAC filter table entry IEEEMAC LocalIpAddrType The device local IP address infomation FEID The FE on which the port ip resides uint32 IfIndex port index on the specified FE uint32 IPaddr IP address of the port IPAddr netmask netmask of this ip address IPAddr BcastAddr The associated Broadcast address of the ip address IPAddr LocalIpv6AddrType Wang, et al. Expires September 4, 2010 [Page 19] Internet-Draft ForCES LFB Library March 2010 The device local IPv6 address infomation FEID The FE on which the port ip resides uint32 IfIndex port index on the specified FE uint32 IPv6addr IP address of the port IPv6Addr prefixlen prefix length of this ip address uint32 IPv4Addr IPv4 address uint32 IPv6Addr IPv6 address byte[16] IPv4Prefix prefix defined by an address and a prefix length address Address part IPv4addr prefixlen Prefix length part Wang, et al. Expires September 4, 2010 [Page 20] Internet-Draft ForCES LFB Library March 2010 uchar IPv4NextHopInfoType IPv4 nexthop information,include nexthop ip address, output FE and interface etc. NexthopID nexthop id uint32 FEID output FE id uint32 OutputPortID output port index uint32 MTU The maximum transmition unit of the nexthop link. uint32 Flags Associated flags of the nexthop,such as local delivery,multicast etc. NextHopFlagsType NexthopIPaddr IP address of the nexthop IPv4Addr L2Index Wang, et al. Expires September 4, 2010 [Page 21] Internet-Draft ForCES LFB Library March 2010 index into the L2 link layer table,such as IPv4 ARP table or IPv6 NBR table. uint32 EncapNeeded The type of encapsulation needed on the packet. EncapType IPv4FibEntryType IPv4 forwarding table entry. prefix IPv4 prefix. IPv4Prefix FEID output FE id uint32 OutputPortID output port index uint32 MTU The maximum transmition unit of the nexthop link. uint32 Flags Associated flags of the nexthop,such as local delivery,multicast etc. NextHopFlagsType NexthopIPaddr IP address of the nexthop IPv4Addr Wang, et al. Expires September 4, 2010 [Page 22] Internet-Draft ForCES LFB Library March 2010 L2Index index into the L2 link layer table,such as IPv4 ARP table or IPv6 NBR table. uint32 EncapNeeded The type of encapsulation needed on the packet. EncapType IPv4PrefixTableEntry IPv4 prefix table entry Prefix IPv4 address prefix IPv4Prefix NexthopID Index into the nexthop table. uint32 IPv4UcastLPMStatisticsType statistics of IPv4UcastLPM LFB InRcvdPkts The total number of input packets received from interfaces, including those received in error uint64 FwdPkts IPv4 packet forwarded by this LFB uint64 NoRoutePkts The number of IP datagrams discarded because no Wang, et al. Expires September 4, 2010 [Page 23] Internet-Draft ForCES LFB Library March 2010 route could be found to transmit them to their destination. uint64 InDeliverPkts The total number of input datagrams successfully delivered to IP user-protocols (including ICMP). uint64 IPv4ValidatorStatisticsType IPv4 validator LFB statistics type badHeaderPkts The total number of input datagrams with bad ip header uint64 badTotalLengthPkts The total number of input datagrams with bab length uint64 badTTLPkts The total number of input datagrams with bad TTL uint64 badChecksum The total number of input datagrams with bad checksum uint64 IPv6Prefix IPv6 prefix Wang, et al. Expires September 4, 2010 [Page 24] Internet-Draft ForCES LFB Library March 2010 IPv6addr address part of the prefix IPv6Addr prefixlen length of the prefix uint32 IPv6NextHopInfoType IPv4 nexthop information,include nexthop ip address, output FE and interface etc. NexthopID nexthop id uint32 FEID output FE id uint32 OutputPortID output port index uint32 MTU The maximum transmition unit of the nexthop link. uint32 Flags Associated flags of the nexthop,such as local delivery,multicast etc. NextHopFlagsType NexthopIPv6addr IP address of the nexthop IPv6Addr Wang, et al. Expires September 4, 2010 [Page 25] Internet-Draft ForCES LFB Library March 2010 L2Index index into the L2 table uint32 EncapNeeded The type of encapsulation needed on the packet. EncapType IPv6PrefixTableEntry IPv6 prefix table entry Prefix IPv6 address prefix IPv6Prefix NexthopID index to the nexthop table. uint32 IPv6LPMClassiferStatisticsType statistics of IPv6LPMClassifier LFB InRcvdPkts The total number of input packets received from interfaces,including those received in error uint64 FwdPkts IPv4 packet forwarded by this LFB uint64 NoRoutePkts The number of IP datagrams discarded because no Wang, et al. Expires September 4, 2010 [Page 26] Internet-Draft ForCES LFB Library March 2010 route could be found to transmit them to their destination. uint64 InDeliverPkts The total number of input datagrams successfully delivered to IP user-protocols (including ICMP). uint64 IPv6ValidatorStatisticsType IPv6 validator LFB statistics type badHeaderPkts The total number of input datagrams with bad ip header uint64 badTotalLengthPkts The total number of input datagrams with bab length uint64 badTTLPkts The total number of input datagrams with bad TTL uint64 badChecksum The total number of input datagrams with bad checksum uint64 NextHopFlagsType Flags used to define different nexthop behaviors Wang, et al. Expires September 4, 2010 [Page 27] Internet-Draft ForCES LFB Library March 2010 uint32 local Packets match the nexthop entry with this flag are delivered to the higher level protocols. drop Packets match the nexthop entry with this flag are to be dropped. broadcast The route associated with this nexthop is a broadcast. multicast The route associated with this nexthop is multicast. WeightTableEntryType Weight table for queues. QueueID queue id uint32 weight weight of the queue. uint32 NbrState IPv6 neighbour entry resolution state. uchar Wang, et al. Expires September 4, 2010 [Page 28] Internet-Draft ForCES LFB Library March 2010 INCOMPLETE Address resolution is being performed on the entry.Specifically, a Neighbor Solicitation has been sent to the solicited-node multicast address of the target,but the corresponding Neighbor Advertisement has not yet been received. REACHABLE Positive confirmation was received within the last ReachableTime milliseconds that the forward path to the neighbor was functioning properly. While REACHABLE,no special action takes place as packets are sent. STALE More than ReachableTime milliseconds have elapsed since the last positive confirmation was received that the forward path was functioning properly. While stale, no action takes place until a packet is sent.The STALE state is entered upon receiving an unsolicited Neighbor Discovery message that updates the cached link-layer address. Receipt of such a message does not confirm reachability, and entering the STALE state insures reachability is verified quickly if the entry is actually being used. However,reachability is not actually verified until the entry is actually used. DELAY More than ReachableTime milliseconds have elapsed since the last positive confirmation was received that the forward path was functioning properly,and a packet was sent within the last DELAY_FIRST_PROBE_TIME seconds. If no reachability confirmation is received within DELAY_FIRST_PROBE_TIME seconds of entering the DELAY state, send a Neighbor Solicitation and change the state to PROBE. PROBE A reachability confirmation is actively sought by retransmitting Neighbor Solicitations every RetransTimer milliseconds until a reachability Wang, et al. Expires September 4, 2010 [Page 29] Internet-Draft ForCES LFB Library March 2010 confirmation is received. ArpTableEntryType Arp entry. Index Index of the arp table. uint32 NeighborIP IP address of the neighbour. IPv4Addr SrcMac Source MAC. IEEEMAC NeighborMac Mac of the Neighbor. IEEEMAC State The state of the address resolution progress. ArpStateType NbrTableEntryType IPv6 neighbour table entry. Index Index of the arp table. uint32 NeighborIPv6 Wang, et al. Expires September 4, 2010 [Page 30] Internet-Draft ForCES LFB Library March 2010 IP address of the neighbour. IPv6Addr SrcMac Source MAC. IEEEMAC NeighborMac Mac of the Neighbor. IEEEMAC State The state of the entry's resolution progress. NbrState DCHostTableEntryTypev4 Direct connected arp table entry for IPv4. NeighbourIP IP address of the neighbour. IPv4Addr SrcMac Source MAC. IEEEMAC NeighborMac Mac of the Neighbor. IEEEMAC DCHostTableEntryTypev6 Direct connected arp table entry for IPv4. NeighbourIPv6 Wang, et al. Expires September 4, 2010 [Page 31] Internet-Draft ForCES LFB Library March 2010 IP address of the neighbour. IPv4Addr SrcMac Source MAC. IEEEMAC NeighborMac Mac of the Neighbor. IEEEMAC PacketType The packet type code. uchar IPv4Ucast IPv4 unicast packet. IPv4Mcast IPv4 multicast packet. IPv6Ucast IPv6 unicast packet. IPv6Mcast IPv6 multicast packet. DispatchTableType The dispatch table type. PacketType The type of the packet.IPv4Uncast,IPv6Ucast, IPv4Mulcast,IPv6Mulcast etc. Wang, et al. Expires September 4, 2010 [Page 32] Internet-Draft ForCES LFB Library March 2010 PacketType index The index of the output group to output the packets. uint32 MetaType Metadata type definition. MetadataID The ID of the metadata,the value is standardalized in the corresponding LFB definition RFCs. uint32 MetadataName The name of the metadata. String MetadataClassyTableType The meta data classifying table. value Value of the meta data. uint32 index The index of the port in the output group to use for outputing the packets. uint32 EncapType Encapsulation type. Wang, et al. Expires September 4, 2010 [Page 33] Internet-Draft ForCES LFB Library March 2010 uchar Link Link layer encapsulation such as Ethernet and PPP. InterFE Inter FE communication encapsulation. Tunnel Tunnel encapsulation such as IP-in-IP. IPAddress IP layer address. Ipv4 IPv4 address. IPv4Addr Ipv6 IPv6 address. IPv6Addr ArpStateType The arp entry state. uchar Mannul The entry is mannully set. Wang, et al. Expires September 4, 2010 [Page 34] Internet-Draft ForCES LFB Library March 2010 InSolicit The peer's level 2 address is still in requesting. Vaild The address resolution have been completed successfully,it now can be used in the data packets forwarding. NextHopID An index into a Next Hop entry in Nexthop table 1 int32 ExceptionID Exception Types 2 uint32 Options Packets with options,for IPv6 Packet with next-header set to hop-by-hop header(0). LengthMismatch The packet length reported by link layer is less than the total length field. BadTTL The packet can't be forwarded as the TTL has expired. Multicast The packet received is a multicast packet. Wang, et al. Expires September 4, 2010 [Page 35] Internet-Draft ForCES LFB Library March 2010 FragRequired The MTU for outgoing interface is less than the packet size. Redirect The outgoing port is same as the one on which the packet is received. LocalDelivery The packet is for a local interface. LimitedBroadcast The packet received as limited broadcast. InputPortID At which interface the packet arrive. 3 uint32 OutputPortID The interface out which the packet will emmit. 4 uint32 NextHopIP Nexthop IPv4 address. 5 IP4Addr NexthopIPv6 Nexthop IPv6 address 6 IPv6Addr Wang, et al. Expires September 4, 2010 [Page 36] Internet-Draft ForCES LFB Library March 2010 PacketLength The length of the packet in octets. 7 uint32 PacketType Type of the packet 8 uint32 IPv4 IPv4 packet IPv6 IPv6 packet TaggedFrame packet with metadata MetaDataFrame meta data only QueueID The queue ID 9 uint32 QueueOperationCmd The type of operation on the queue,there are two types defined here: enqueue and dequeue. 10 uchar Enqueue Wang, et al. Expires September 4, 2010 [Page 37] Internet-Draft ForCES LFB Library March 2010 Enqueue command. Dequeue Dequeue command. SrcFEID Source blade ID. 11 uchar DstFEID Destination blade ID. 12 uchar NexthopIndex Nexthop index into the link layer address resolution table. 13 uint EncapMethod how should the following LFBs do to encapsulate the packets,such as link encapsulation which means the packets need to encapsulate link layer header before sending to media;inter FE communication encapsulation which means the packets need to first encapsulate inter FE communication header before transimiting to other FEs;tunnel encapsulation which means the packet need do extra tunnel encapsulation before sending out to media. 14 EncapType Wang, et al. Expires September 4, 2010 [Page 38] Internet-Draft ForCES LFB Library March 2010 6. LFB Classes 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 relate to packet processing in the data path. LFB classes are the basic building blocks of the FE model. Only for better understanding purposes, LFB classes defined in this document are further categorized into groups of LFBs, including Core LFBs, Port LFBs, etc. The following sections describe the LFB classes according to the groups. 6.1. Core LFBs The core LFBs provide basic ForCES functionality for FE in a ForCES system. Two core LFBs are defined: the FE Protocol LFB and the FE Object LFB. 6.1.1. FE Protocol LFB The FE Protocol LFB is defined as a logical entity in each FE that is used to control the ForCES protocol. It repsesents FE Protocol attributes like supportable ForCES protocol versions, current running version, FE restart policy, CE failover policy, etc. The ForCES protocol specification document FE-MODEL [I-D.ietf-forces-model] defines the LFB in details and specifes that every FE must have one FE Protocol LFB. The definition of the LFB is included in this base LFB library by using "load" element: 6.1.2. FE Object LFB The FE Object LFB is defined to make the FE information easily accessible. Information like the FE Name, FE ID, FE State, LFB Topology in the FE are represented in the class of LFB. The FE model documentFE-MODEL [I-D.ietf-forces-model] defines the LFB in details and specifies that every FE must have one FE Object LFB. The definition of the LFB is included in this base LFB library by Wang, et al. Expires September 4, 2010 [Page 39] Internet-Draft ForCES LFB Library March 2010 using "load" element: 6.2. Port LFBs Classes of Port LFBs are LFBs that are related to the operation of FE media interfaces linked to outer networks or other FEs in the same ForCES system. According to different media types, different media port LFBs may have to be defined. For every type of media port, it usually needs to implement encapsulating and decapsulating the IP datagrams with the connected network framing. For the sake of the flexibility, the function of encapsulating and decapsulating are usually categorized in LFB classes as separate LFBs. Even if ports with different media may have different logical abstracts for the attributes, a general description for different ports still exist. A Generic Connectivity LFB is defined for this sake. By use of an FE model XML schema element, specific media port LFBs are then defined in a easier way. 6.2.1. Generic Connectivity LFB This LFB Class provides a generic basis for representing connectivity between the FE and the outside world. The LFB has one or more ports for packets that the FE processing logic is forwrding for transmission by this Connectivity LFB. It has one or more ports for packets that the Connectivity LFB has received and is handing to the FE processing logic. Multiple ports for handline packets are supported so that protocol specific encapsulation and demultiplexing can be provided by this LFB. This LFB also has ports for sending packets to lower layer Connectivity LFBs and receiving packets from such lower layer Connectivity LFBs. This enables support for the processing components of interface stacks, such as PPP over Ethernet or Ethernet over MPLS. For packets arriving from Media or lower layer connectivity, this LFB will perform appropriate media validation, then remove media specific headers, and place the relevant information in meta-data. For ethernet, the Source MAC would be in meta-data. For Frame Relay or ATM, a circuit identifier would be in meta-data. For Ethernet with VLANs, this meta-data would indicate which VLAN the packet came from. For packets to be transmitted, meta-data indicating the destination (destination MAC or outgoing circuit, etc.) is required. This LFB will also include statistical components such as the number of octets and packets sent and received, the number of various input and output errors, etc. Wang, et al. Expires September 4, 2010 [Page 40] Internet-Draft ForCES LFB Library March 2010 6.2.2. Ethernet Port LFBs (TBD) 1. EtherPort LFB LFB for Ethernet ports 2. EtherDecap LFB An LFB class for definition of Ethernet decapsulation and Ethernet filtering functions. 3. EtherEncap LFB An LFB classifier definition for completes ethernet encapsulation fuctions. 6.2.3. POS Port LFBs (TBD) 6.2.4. ATM Port LFBs (TBD) 6.3. Address Resolution LFBs (TBD) This LFB class provides the function of address resolution for IPv4/ IPv6 nodes. 1. ARP This LFB class provides the function of address resolution for IPv4 node. 2. IPv6 Address Resolution This LFB class provides the function of IPv6 address resolution part of neighbor discovery protocol.It provides an offload of ND protocol processing to FE.It process the following ND messages: neighbour solicitation and neighbour advertisement. Wang, et al. Expires September 4, 2010 [Page 41] Internet-Draft ForCES LFB Library March 2010 6.4. ICMP LFBs (TBD) 1. ICMP Geneartor This LFB class provide some basic ICMP function. It only generate the following ICMP messages: ICMP destination unreachable and time excceeded. 2. ICMPv6 Generator This LFB class provide some basic ICMPv6 function, it only generate the following ICMP messages for the packets that need some basic ICMP processing: destination not reachable and time excceeded. 6.5. IP Packet Validation LFBs (TBD) 1. IPv4 Validator An LFB Class definition for validates the IPv4 packet. This LFB validates the IP version and header length fields, including verifying that the packet length is at least as long as the header indicates. 2. IPv6 Validator An LFB Class definition for validates the IPv6 packet. This LFB validates the IP version and header length fields, including verifying that the packet length is at least as long as the header indicates. 6.6. Classifier LFBs (TBD) 1. Metadata Classifier LFB This LFB class provides the function of classify packets according to the meta data. Now it only works on one meta data. 2. Arbitrary Classifier LFB Wang, et al. Expires September 4, 2010 [Page 42] Internet-Draft ForCES LFB Library March 2010 This is a class definition for an Arbitrary Classifier LFB. The input is a port group, and the match conditions can include the port in their test. This allows the topology to carry some information if desired. The match conditions can select an output from the SuccessOuput output port group. If no condition matches, the packet will be sesnt to the FailOutput port. 6.7. Forwarding LFBs (TBD) Forwarding LFBs are specifically for implementing IP packet forwarding tasks. 6.7.1. Unicast Longest Prefix Match LFBs 1. IPv4UcastLPM IPv4 Longest Prefix Match Lookup LFB 2. IPv6UcastLPM An LFB class definition for IPv6 longest prefix lookup function. 6.7.2. Nexthop Applicator LFBs 1. IPv4 NextHop Applicator An LFB definition for applicating next hop action to IPv4 packets, the actions include:TTL operation,checksum recalculation. 2. IPv6UcastNexthopApplicator An LFB for applicating next hop action to IPv6 packets,actions mainly inlcude TTL incrementation and checksum recalculation. 6.8. QoS Control LFBs (TBD) To build an actual forwarder, one must include some limited for of queueing and scheduling. Queues are entities which store packets. Schedulers are entities which react to the state of queues and cause packets to be emitted from queues. The actual interaction between queues and schedulers (and their real world degree of separation) is quite complex. A very complex LFB Wang, et al. Expires September 4, 2010 [Page 43] Internet-Draft ForCES LFB Library March 2010 model would be required to represent all the complexity. Additionally, there is the issue of representing the relationship between the queue and the scheduler. A simple approach has been taken in these class definitions. A queue element consists of an input port (called InData) on which it receives data packets, and output port (called OutData) on which it will send packets when permitted by its definition or the scheduler. Its relationship to scheduluers is represented by a set of output ports (the group OutCountrol) and an input port (called InControl). These ports are defined to carry packets consisting only of meta- data. In fact, these ports are an abstraction, and what one might call a legal fiction. An element of the OutControl group represents the fact that a scheduler is aware of the state of that queue element. The InControl port represents the fact that one or more schedulers connected to that port are controlling that queue. There is no meta-data defined for actual exchange on these ports, as their real world realization is highly implementation dependent. To complete this picture, a schedule has a group of input ports (Watchers) representing the connectivity to queues it is aware of, and a group of output ports (Controllers) representing control over queues. This allows for the simple case of a controller who monitors and controls a single set of queues, and more interesting cases where the control of certain queues may depend upon the state of queues whihc are not under the control of the scheduler. The Queues and schedulers LFBs that are defined in this library are: 1. Scheduler 2. Queue 3. WRRSched 6.8.1. Scheduler LFBs 1. Generic Scheduler This defines a base LFB class for schedulers. Schedulers have an Input Port group called Watchers for representing the queues they watch, and an Output Port group called Controllers fro representing the queues they control. 2. WRRSched Weighted round robin scheduler. Wang, et al. Expires September 4, 2010 [Page 44] Internet-Draft ForCES LFB Library March 2010 6.8.2. Queue LFBs Queues have a packet input, a packet output, a control input, and a group of control outputs. The control ports represent the control relationships with scheduluers. 6.9. Miscellaneous Packet Manipulation LFBs (TBD) 1. Packet Trimmer LFB LFB removes data from the front of a packet. 2. Duplicator LFB An LFB Class definition for packet duplicator LFB. Any packet received on an input port is logically copied and sent to all output ports. 3. IPv4 Option Proccessing LFB This LFB class process the IPv4 packet with options, it can process on the following options: Router-alert option. 4. IPv6 Extend Header Processing LFB This LFB class process the IPv6 packet with extended header, For the moment, the packets to this LFB are redirect to RedirectSink LFB by default. 6.10. Redirect LFB (TBD) An LFB Class definition for exchanging data packets between the FE and the CE. This LFB represents a point of exchagne of data packets between the CE and the FE. Packets with meta-data are exchanged. It is expected that the output port of a RedirectLFB, if it is connected at all, will be connected to a meta-data redirector. Wang, et al. Expires September 4, 2010 [Page 45] Internet-Draft ForCES LFB Library March 2010 7. XML Definition for Base LFB Library This library provides base LFB class definitions. EtherPort LFB for Ethernet ports 1.0 PacketsFromProcessingUnit Ports for receiving packets from processing unit such as NP,that will be sent to media. EthernetII OutputPort PacketsFromMedia Ports for receiving packets from ethernet media. EthernetII Wang, et al. Expires September 4, 2010 [Page 46] Internet-Draft ForCES LFB Library March 2010 PacketsToProcessingUnit Ports for sending packets to processing unit such as NP for further processing. EthernetII InputPort PacketsToMedia Ports for sending packets to media. EthernetII IfIndex A unique value for each interface. Its value ranges between 1 and the value of total number of interfaces in the system. The value for each interface must remain constant at least from one re-initialization of the entity's network management system to the next re-initialization. uint32 IfName Name of this port string[16] LinkSpeed Speed of this port LANSpeedType MTU Maximum transmition unit uint32 Wang, et al. Expires September 4, 2010 [Page 47] Internet-Draft ForCES LFB Library March 2010 OperaStatus Operate state of this port. PortStatusValues "down" AdminStatus Administrator's state of this port PortStatusValues "down" PromiscuousMode Whether the interface is in promiscuous mode booleanType "no" CarrierStatus whether the port is linked with an connector. booleanType "no" OperMode The port operation mode,must be one of the following values:Auto,Half-duplex,Full-duplex NegotiationType "auto" SrcMACAddr source MAC IEEEMAC MacAliasTable A series of MACs that the port can receive frame on. IEEEMAC Wang, et al. Expires September 4, 2010 [Page 48] Internet-Draft ForCES LFB Library March 2010 StatsEnable whether enable the statistics in this LFB. booleanType "no" PortStats port statistics. PortStatsType Ipaddr IP layer Address. IPAddress PortStatusChanged Port status has changed since last time reporting. OperaStatus OperaStatus EtherDecap An LFB class for definition of Ethernet decapsulation and Ethernet filtering functions 1.0 PacketsIn Packets from other LFB. EthernetII Wang, et al. Expires September 4, 2010 [Page 49] Internet-Draft ForCES LFB Library March 2010 DecapOut Ethernet decapsulation output. Arbitrary DispatchTable This table is used for selecting output in the ouput group for the incoming packet stream. DispatchTableType IPv4Validor An LFB Class definition for validates the IPv4 packets. 1.0 ValidatePktsIn Port used to receive IPv4 packet for validation. IPv4 SuccessOut Out port for the packets passing the validation. Wang, et al. Expires September 4, 2010 [Page 50] Internet-Draft ForCES LFB Library March 2010 IPv4 ExceptionOut Output port for the packets needed to be dealt by higher level protcol stacks.The following packets are identified as exception packets:1 Packet with header length>5;2 Packet with destination address equal to 255.255.255.255;3 Packet with expired TTL (checked after a forwarding decision is made);4 Packet length error. ExceptionID FailOutput Output for packets failed to pass the validation. IPv4 StatsEnable whether to gather statistics in this LFB. booleanType "no" IPv4ValidatorStats ipv4 validator LFB statistics IPv4ValidatorStatisticsType Detailed validation process please refer to RFC1812 and RFC2644. Wang, et al. Expires September 4, 2010 [Page 51] Internet-Draft ForCES LFB Library March 2010 IPv4UcastLPM IPv4 Longest Prefix Match Lookup LFB 1.0 PktIn The port to receive IPv4 packets from other LFBs IPv4 SuccessOut Successful output when all is fine. IPv4 NextHopID FEID OutputPortID MTU Flags NexthopIPAddr EncapMethod ExceptionOut Exception output IPv4 InputPortID ExceptionID Wang, et al. Expires September 4, 2010 [Page 52] Internet-Draft ForCES LFB Library March 2010 FailOutput Dropper IPv4 PrefixTable IPv4 prefix table IPv4PrefixTableEntry IPv4PrefixTableEntry.prefix Fib IPv4 unicast forwarding table. IPv4FibEntryType IPv4FibEntryType.prefix LocalIpAddrTable The table of interfaces's ip address infomation on the local device LocalIpAddrType IPv4Stats The IPv4 associated statistics IPv4UcastLPMStatisticsType Wang, et al. Expires September 4, 2010 [Page 53] Internet-Draft ForCES LFB Library March 2010 PrefixTableLimit maxium number of prefix supported by this LFB uint32 LocalIpAddrTableLimit maxium number of IP address entrys supported by this LFB uint32 This LFB represents the IPv4 longest prefix match lookup operation. IPv4NextHopApplicator An LFB definition for applicating next hop action to IPv4 packets,the actions include:TTL operation,checksum recalculation. 1.0 PktIn Port used to receive IPv4 packets from other LFBs IPv4 NextHopID FEID OutputPortID MTU Flags NexthopIPAddr EncapMethod Wang, et al. Expires September 4, 2010 [Page 54] Internet-Draft ForCES LFB Library March 2010 SuccessOut Output port for packet successfully fulfill the nexthop application. IPv4 DstFEID OutputPortID L2Index NextHopIP EncapMethod ExceptionOut Output for packets need deep dealt by higher level protocol stacks. IPv4 InputPortID ExceptionID FailOutput Output for packets failed the nexthop application operation. IPv4 Wang, et al. Expires September 4, 2010 [Page 55] Internet-Draft ForCES LFB Library March 2010 NextHopTable Nexthop table IPv4NextHopInfoType NextHopTableLimit Maxium number of nexthops this LFB supports uint32 IPv6Validator A LFB class definition for validating correctness of IPv6 packets 1.0 ValidateIn Input port for packets to be validated. IPv6 SuccessOut Output port for packets passing the validation. IPv6 ExceptionOut Output port for exception packet.The following Wang, et al. Expires September 4, 2010 [Page 56] Internet-Draft ForCES LFB Library March 2010 packets are identified as Exception packet:1 Packet with next header set to Hop-by-Hop.2 The packet length reported by link layer is less than the total length field.3 Packet with a link local destination address;4 The packet received as limited broadcast.5 Packet with multicast destination address (the MSB of the destination address is 0xFF); IPv6 ExceptionID FailOut Output port for packet failing the validation. IPv6 IPv6ValidatorStats IPv6 validator LFB statistics IPv6ValidatorStatisticsType Detailed validation process could refer to RFC2460 and RFC2373. IPv6UcastLPM An LFB class definition for IPv6 longest prefix lookup function. 1.0 PktIn The port to receive IPv6 packets needed to do IPv4 LPM. Wang, et al. Expires September 4, 2010 [Page 57] Internet-Draft ForCES LFB Library March 2010 IPv6 SuccessOut Output for packets that have find the correct route. IPv6 NextHopID FailOutput LPM failed. IPv6 PrefixTable IPv6 prefix table IPv6PrefixTableEntry IPv6PrefixTableEntry.prefix LocalIpv6AddrTable The table of interfaces's ip address infomation on the local device LocalIpv6AddrType Wang, et al. Expires September 4, 2010 [Page 58] Internet-Draft ForCES LFB Library March 2010 IPv6Stats The IPv6 associated statistics IPv6LPMClassiferStatisticsType PrefixTableLimit maxium number of prefix supported by this LFB uint32 LocalIpv6AddrTableLimit maxium number of IPv6 address entrys supported by this LFB uint32 IPv6UcastNexthopApplicator An LFB for applicating next hop action to IPv6 packets, actions mainly inlcude TTL incrementation and checksum recalculation. 1.0 PktIn Input port for packets to be applicate nexthop. IPv6 NextHopID SuccessOut Output port for packet successfully fulfill the Wang, et al. Expires September 4, 2010 [Page 59] Internet-Draft ForCES LFB Library March 2010 nexthop application. IPv6 FEID OutputPortID L2Index NextHopIPv6 EncapMethod ExceptionOut Output port for exception packet.The following packets are identified as Exception packet:1 Packet with Hop Limit zero.2 The MTU for outgoing interface is less than the packet size.3 The outgoing port is same as the one on which the packet is received.4 The packet is for a local interface. IPv6 InputPortID ExceptionID FailOutput Output for packets failed the nexthop application operation. IPv6 NextHopTable Nexthop table Wang, et al. Expires September 4, 2010 [Page 60] Internet-Draft ForCES LFB Library March 2010 IPv6NextHopInfoType NextHopTableLimit Maxium number of nexthops this LFB supports uint32 EtherEncap An LFB classifier definition for completes ethernet encapsulation fuctions 1.0 EncapIn Port for receiving packets needed to build Ethernet encapsulation. IPv4 IPv6 L2Index NextHopIP NextHopIPv6 PacketType SuccessOut EthernetII Wang, et al. Expires September 4, 2010 [Page 61] Internet-Draft ForCES LFB Library March 2010 ExceptionOut packet can't find the associated L2 information IPv4 IPv6 ArpTable Ethernet arp table. ArpTableEntryType NbrTable IPv6 neighbour table. NbrTableEntryType DCHostTablev4 Direct connected host arp table for IPv4. DCHostTableEntryTypev4 DCHostTablev6 Direct connected host arp table for IPv6. DCHostTableEntryTypev6 Wang, et al. Expires September 4, 2010 [Page 62] Internet-Draft ForCES LFB Library March 2010 ArpTableLimit Max number of arp entries in arp table. uint32 NbrTableLimit Max number of neighbours in neighbour table. uint32 DCHostTablev4Limit The limit on Direct connected host table for IPv4. uint32 DCHostTablev6Limit The limit on Direct connected host table for IPv6. uint32 Scheduler Base scheduler LFB. 1.0 Watcher Input for watching the queues to be scheduled. Queues to be scheduled can transmit packet enqueue and dequeue infomation to scheduler through these port. MetadataFrame QueueID PacketLength QueueOperationCmd Wang, et al. Expires September 4, 2010 [Page 63] Internet-Draft ForCES LFB Library March 2010 OutControl Control output,this output is used by scheduler to communicate commands to it's controlled queues such as dequeue a packet. MetadataFrame QueueOperationCmd QueueScheduledLimit Max number of queues that can be scheduled by this scheduler. uint32 Queue Queue LFB. 1.0 InControl Input from scheduler QueueOperationCmd InData Input port for data packet. Arbitrary Wang, et al. Expires September 4, 2010 [Page 64] Internet-Draft ForCES LFB Library March 2010 PacketLength OutToController Output to queue controller MetadataFrame QueueID PacketLength QueueOperationCmd OutData Data packet output Arbitrary CurLen Current length of the queue in number of packets. uint32 QueueLenLimit Maximum length of the queue in number of packets. uint32 Wang, et al. Expires September 4, 2010 [Page 65] Internet-Draft ForCES LFB Library March 2010 RedirectSink This class definition provides for the function of sinking data packets that needed to be sent to CE. 1.0 InFromOtherLFBs Packets input from other LFBs and needed to sent to CE. IPv4 IPv6 InputPortID PacketLength PacketType RedirectTap This class provides the function of sinking data packets that comes from CE and needed to be sent out by this FE. 1.0 OutputToOtherLFBs Packets input received from CE. IPv4 IPv6 PacketType OutputPortID PacketLength Wang, et al. Expires September 4, 2010 [Page 66] Internet-Draft ForCES LFB Library March 2010 DispatchTable The table to dispatch the packets to different LFB. DispatchTableType outGroupNumOfPorts The number of ports in output group. uint32 MaxNumOfoutGroupPorts The maxium number of ports in the output group. uint32 WRRSched Weighted round robin scheduler. 1.0 Scheduler WeightTable Weight table for queues to be scheduled. WeightTableEntryType IPv6AddrResolution This LFB class provides the function of IPv6 address resolution part of neighbor discovery protocol.It provides an offload of ND protocol processing to FE.It process the following ND messages:neighbour solicitation and neighbour advertisement. 1.0 AddrResDataPktIn The IPv6 data packet that need to do the address Wang, et al. Expires September 4, 2010 [Page 67] Internet-Draft ForCES LFB Library March 2010 resolution. IPv6 AddrResProtoPktIn The neighbour discovery packet related to addresolution. IPv6 AddrResDataPktOut The IPv6 packet that have encapsulated with the correct ethernet L2 info and need to be sent out to link. EthernetII AddrResProtoPktOut The IPv6 neighbour discovey packet wich has been encapsulation with the correct ethernet L2 info. EthernetII Nbrtable This table is an alias to the IPv6 neighbour table in the EtherEncap LFB. NbrTable Wang, et al. Expires September 4, 2010 [Page 68] Internet-Draft ForCES LFB Library March 2010 ICMPv6Generator This LFB class provide some basic ICMPv6 function,it only generate the following ICMP messages for the packets that need some basic icmp processing:destination not reachable and time excceeded. 1.0 PktIn The IPv6 packet that need icmp processing. IPv6 ExceptionID ICMPv6PktOut The output for the ICMPv6 packets generated according to the input IPv6 packet and the ExceptionID. IPv6 ExtendHeaderProc This LFB class process the IPv6 packet with extended header,For the moment,the packets to this LFB are redirect to RedirectSink LFB by default. 1.0 PktIn The IPv6 packet with extended header in. Wang, et al. Expires September 4, 2010 [Page 69] Internet-Draft ForCES LFB Library March 2010 IPv6 PktOut According to the Extended header type the packet may have different next proccesing LFB.Now by default we send all the packet with extended header to CE. IPv6 arp This LFB class provides the function of address resolution for IPv4 nodes. 1.0 AddrResDataPktIn The IPv4 data packet that need to do the address resolution. IPv4 ArpPktIn The neighbour discovery packet related to addresolution. IPv4 Wang, et al. Expires September 4, 2010 [Page 70] Internet-Draft ForCES LFB Library March 2010 AddrResDataPktOut The IPv4 packet that have been encapsulated with the correct ethernet L2 info and need to be sent out to link. EthernetII ArpOut The arp packet out. EthernetII Arptable This table is an alias of the arp table in the EtherEncap LFB. ArpTable ICMPGenerator This LFB class provide some basic ICMP function,it only generate the following ICMP messages:ICMP destination unreachable and time excceeded. 1.0 PktIn The IPv4 packet that need icmp processing. IPv4 ExceptionID Wang, et al. Expires September 4, 2010 [Page 71] Internet-Draft ForCES LFB Library March 2010 ICMPPktOut The output for the ICMP packets generated according to the input packet and the ExceptionID. IPv4 MetadataClassifier This LFB class provides the function of classify packets according to the meta data.Now it only works on one meta data. 1.0 PktIn Packets need to do the classification. Arbitrary Arbitrary ClassifiedOut The output group for the classified packets. Arbitrary Wang, et al. Expires September 4, 2010 [Page 72] Internet-Draft ForCES LFB Library March 2010 MetaDataID The metadata id that this classifier works on. uint32 MetaDataName The name of the meta data that this classifier works on. string MetadataClassifyTable The meta data classifying table. MetadataClassyTableType OutNumOfPorts The number of ports in the output group. uint32 MaxOutNumOfPorts Maxium number of ports in the output group. uint32 OptionProc This LFB class process the IPv4 packet with options, it can process on the following options:Router-alert option. 1.0 PktIn The IPv4 packet with options in. Wang, et al. Expires September 4, 2010 [Page 73] Internet-Draft ForCES LFB Library March 2010 IPv4 PktOut According to the Option type the packet may have different next proccesing LFB.Now by default we send all the packet with extended header to CE. IPv4 Wang, et al. Expires September 4, 2010 [Page 74] Internet-Draft ForCES LFB Library March 2010 8. Base LFB Library Use Case for Typical Router Functions This section demonstrates examples on how the LFB classes defined by the Base LFB library in Section 7 are applied to the achievements of 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 implementors of the base LFB library should not be limited by the examples. 8.1. IP Forwardings IP packets to be forwarded are from interfaces conneted via a kind of media to outer networks. A Port LFB receives link layer packets. CE may control the port LFB status by the LFB components defined in the library. Link layer packets are delivered to a decapsulation LFB to decapsulate to IP packets. The LFB also provides IP packet distinguishing by classifying IP packet according to its types like IPv4 or IPv6, unicast or multicast, and ARP packet. The packet type information is included in a IPPacketType metadata and the metadata is associated with every decapsulated IP packet. Followed decapsulation LFBs are usually IP validation LFBs which further validate IP packets according to IP protocol. The LFB also distinguishes if the IP packets are exceptional packets like ICMP packets other than IP packets to be further forwarded. The exceptional packets are then associated with metadata indicating the packet types and delivered to metadata classifier for specific Wang, et al. Expires September 4, 2010 [Page 75] Internet-Draft ForCES LFB Library March 2010 classification and further processing. Validated IP unicast packets for forwarding are delivered to unicast Longes Prifix Match(UcastLPM) LFB, which produce nexthop information for forwarding. The nexthop information is represented by a nexthopID metadata. IP packets with associated nexthop metadata are delivered to the NextHopApplicator LFB. The LFB decides output ports for the IP packets. Note that when IP packets need to traverse FEs for forwarding, the LFB may also only decides the local FE output port to the other FE and makes the packet to carry the nexthop information to that FE. IP packets with nexthop applied are then encapsulated by a link layer encapsulation LFB according to the egress media and put on to the appropriate output ports. In this process, address resolution LFBs may have to be applied to decide the link layer output addresses for the packets. Moreover, the queue management LFBs and scheduler LFBs may be applied in the process to achieve individual QoS requirements. Figure 1 shows the typical LFB processing path for the IPv4 unicast forwarding case. Figure 1. (TBD) Figure 2 shows the typical LFB processing path for the IPv6 unicast forwarding case. Figure 2. (TBD) 8.2. Address Resolution TBD 8.3. ICMP TBD 8.4. Running Routing Protocol TBD 8.5. Network Management TBD Wang, et al. Expires September 4, 2010 [Page 76] Internet-Draft ForCES LFB Library March 2010 9. Contributors The authors would like to thank Jamal Hadi Salim and Ligang Dong who made a major contribution 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 Wang, et al. Expires September 4, 2010 [Page 77] Internet-Draft ForCES LFB Library March 2010 10. Acknowledgements This document is based on earlier documents from Joel Halpern, Ligang Dong, Fenggen Jia and Weiming Wang. Wang, et al. Expires September 4, 2010 [Page 78] Internet-Draft ForCES LFB Library March 2010 11. IANA Considerations (TBD) Wang, et al. Expires September 4, 2010 [Page 79] Internet-Draft ForCES LFB Library March 2010 12. 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 FE-protocol [I-D.ietf-forces-protocol]. Wang, et al. Expires September 4, 2010 [Page 80] Internet-Draft ForCES LFB Library March 2010 13. References 13.1. Normative References [I-D.ietf-forces-model] Halpern, J. and J. Salim, "ForCES Forwarding Element Model", draft-ietf-forces-model-16 (work in progress), October 2008. [I-D.ietf-forces-protocol] Dong, L., Doria, A., Gopal, R., HAAS, R., Salim, J., Khosravi, H., and W. Wang, "ForCES Protocol Specification", draft-ietf-forces-protocol-22 (work in progress), March 2009. 13.2. 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 September 4, 2010 [Page 81] Internet-Draft ForCES LFB Library March 2010 Authors' Addresses Weiming Wang Zhejiang Gongshang University 18, Xuezheng Str., Xiasha University Town Hangzhou, 310018 P.R.China Phone: +86-571-28877721 Email: wmwang@mail.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 Fenggen Jia National Digital Switching Center(NDSC) Jianxue Road Zhengzhou, 452000 P.R.China Phone: +86-571-28877751 Email: jfg@mail.ndsc.com.cn,fgjia@mail.zjgsu.edu.cn Halpern Joel Ericsson P.O. Box 6049 Leesburg, 20178 VA Phone: +1 703 371 3043 Email: jhalpern@redback.com Wang, et al. Expires September 4, 2010 [Page 82]