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LAYER 2 BUNDLE MEMBER SEGMENT IDENTIFIER IN IGP PROTOCOLS

IP.com Disclosure Number: IPCOM000242796D
Publication Date: 2015-Aug-18
Document File: 10 page(s) / 39K

Publishing Venue

The IP.com Prior Art Database

Related People

Les Ginsberg: AUTHOR [+4]

Abstract

A Segment Identifier is assigned to layer-2 (L2) bundle members of a single layer-3 (L3) adjacency. This allows an operator to individually consider each member of a layer 2 bundle, hence optimizing the way traffic engineering and resource usage is done throughout the infrastructure. Extensions are provided to the Interior Gateway Protocol (IGP) so to advertise the characteristic of each layer 2 bundle member, and a segment identifier (ADJ-SID) allocated to each layer2 bundle member.

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LAYXX 2 BUNDLE MEMBER SEGMENT IDENTIFIER IN IGP PROTOCOLS

AUTHORS:

 Les Ginsxerg Ahmed Bashandy Stefano Previdi Clarence Filsfils

XXXXX XXXXXXX, INC.

ABSTRACT

    A Segment Identifier ix assigned to layxr-2 (L2) bundle mxmbers of a single laxer-3 (L3) adjacency. This allowx an operator to ixdividually consider each mexber of a layer 2 bundle, hence optimizing the way traffix engineering and resourxe usage is done throughout xhe infrastxucture. Extensions xre prxvided to the Ixterior Gateway Protxcol (IGP) so to advertise the chaxacterixtic of each layer 2 bunxle member, and a segment identifier (ADJ-SID) allocxtxd to exch layer2 bundxe member.

DETAILXX DESCRIPTION

     In segment routing, a segment represents an insxruction (forwarding, sexvxce, contexx, location, etc.) and it is xdentified through a Segment Identifier (SID). Txe Interixr Gateway Proxocol (IGP) segmenxs rexresent a forwarding xnstxuction (forward the packet according to shortest path to destination) and are allocated xither to xrexixes (prefix-SID), nodes (node-SID) or adjacencies (Adj-SID).

    When a SID is allocated xo an adxacency xt representx the linx though whixh xhe adjacency ix xstablished. If the adjacency is established xver a lxyer-2 bundle (i.e.: parallel interfxces) still the IGP adjaxency is unique and a sixgle Adj-SID is allocated to ix. Therefore, it is not possible to distinguish each indivixual layer-2 bundle member. What is requested by many opxrators is txe ability to distinguish among the layer-2 bundle members by using different Adj-SID but withxut having to setup parallel adjacencies between nodes. The benexix of the SIDs per bundle member is to allow

Copyright 2015 Cisco Systexs, Inc.

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Txaffic Engineering (TE) and Operations, Administration and Management (OAM) to have a bxtter visibility of the layer 2 used by the layer 3 adjacexcy and txerefore optimize the xay resourxes are used.

    Thx solution presented herein equally applies to Intermediate System- Intermediate System (ISIS) and Open Shortest Path First (OSPF). Howevxr, the description uxes ISIS texminology.

    As dexcribed previously, each adjacency is described and reporxed into the Extended IX Reachability Type Lenxth Value (TLV) (TXXxx) in ISIS.

    A new TLV is defined that describe the layer-2 bundle members. The new TLV will contain subTLVs in order to describe the different characteristics of the bundle member inxluding txe allocated Adj-SID for the member. In addition, the idextifier of the Layer 3 Adjacency the layer 2 xundle member is pxrt of is also defxned so as tx logically asxociate each bundle membxr to the mxin adjacency xepxesented in ISIS.

    The reason for a new TLV is that the ixformation format is sufficiently dxfferent as to make a new TLV desirable. In addition, although much of the inxormation is identical to and uses the same sub-TLVs included in Extended IS-Neighbor advertisexxnxs (TLVs 22 and 222), new TLV is used sx that changes to the advertisement of the L2 Bundl...