Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net 1 Setup and Maintenance of Pseudo- Wires Using RSVP-TE Draft-raggarwa-rsvpte-pw-01.txt Rahul Aggarwal (Juniper) Kireeti Kompella (Juniper) Arthi Ayyangar (Juniper) Dimitri Papadimitriou (Alcatel) Peter Busschbach (Lucent) Nurit Sprecher (Siemens)
2 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Agenda Why RSVP-TE ? RSVP-TE for Traffic Engineered Multi-Segment PWs - Overview Traffic Engineered Multi-Segment PWs and RSVP- TE Discussion
3 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Why RSVP-TE ? Inter-Domain Traffic Engineered Pseudo-wires (PWs) Intra-domain PSN tunnels are RSVP-TE LSPs Look at the entire picture with all the pieces Multi-Segment (MS) PWs and PW TE and PW resiliency RSVP-TE provides existing mechanisms to address all of the above RSVP-TE (RFC 3209) and LSP-Hierarchy (draft-ietf-mpls-lsp- hierarchy) Same tools as those used for inter-domain RSVP-TE PSN Tunnels
4 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Inter-Domain TE PW Signaling using RSVP-TE Overview Instantiate a multi-segment PW as a bi-directional RSVP-TE LSP This “PW LSP” is nested in intra-domain PSN RSVP-TE LSPs between PW segment end-points Targeted RSVP-TE signaling messages between PW segment end-points QoS signaling using TSPEC etc PW Explicit/Record routing using ERO/RRO Single sided signaling Resiliency using Fast-Reroute - draft-ietf-mpls-rsvp-te-fast- reroute
5 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PW TE using RSVP-TE Example CE2 AS1 AS2 PE1 PE3 ASBR1 ASBR2 P P ASBR3 ASBR4 PE2 Nesting over pre-provisioned intra-region TE PSN LSP MS-PW partial path computation to next ASBR Dynamic setup of intra-region TE PSN LSP Forward MS-PW setup request to next ASBR PATH RESV MS-PW with TE from PE1 to PE2 CE1
6 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net RSVP-TE and Traffic Engineered MS-PWs Recap RSVP-TE for PW signaling presented at IETF 60. Traffic Engineered Multi-segment PWs were targeted as a primary motivation Lead to the MS-PW requirements effort MS-PW TE Motivation / Requirements – RSVP-TE applicability analysis Based on MS-PW Requirements effort - draft-martini- pwe3-mh-pw-requirements-01.txt
7 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PW TE and RSVP-TE Motivations Inter-Domain PWs RSVP-TE already supports inter-domain signaling draft-ietf-ccamp-inter-domain-framework-01.txt and draft-ietf- ccamp-inter-domain-rsvp-te-00.txt Not always desirable to setup a direct signaling adjacency between U- PEs Avoid a full mesh of signaling adjacencies between the U-PEs Avoid a full mesh of end-to-end PSN tunnels Instead a U-PE maintains a single adjacency with the neighboring S- PE U-PE/S-PE can establish a RSVP-TE targeted adjacency with the S- PE of the next PSN domain and explicitly route the MS-PW to the destination U-PE
8 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PW TE and RSVP-TE Requirements U-PE signaling the MS-PW must have the ability to select the S-PEs on the MS-PW path RSVP-TE Explicit routing - RFC 3209 Dynamic re-routing around failure points RSVP-TE Fast-reroute - draft-ietf-mpls-rsvp-lsp- fast-reroute
9 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PWs and RSVP-TE Requirements - Resiliency End-to-end backup MS-PW RSVP-TE shared style reservations – RFC 3209 RSVP-TE allows primary and backup PWs to be associated with each other and share resources on common segments Ability to traverse different S-PEs i.e. avoid fate sharing RSVP-TE Explicit routing Mechanisms to perform a fast switchover from a primary PW to a backup PW upon failure detection RSVP-TE global repair mechanisms S-PEs can also use RSVP-TE fast reroute Mechanisms to propagate PW segment failure to other MS-PW segments RSVP-TE PathErr/ResvErr/Notify – Regular procedures
10 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PW TE and RSVP-TE Requirements - QoS End-to-end MS-PW bandwidth reservations RSVP-TE QoS signaling – RFC3209 RSVP-TE can support for diverse QoS models RSVP-TE support for diffserv, traffic priorities RSVP-TE Crankback support - draft-ietf-ccamp- crankback-04.txt Resource/policy admission control into RSVP-TE PSN Tunnels at U-PE and S-PE Based on hierarchical RSVP-TE a la draft-ietf-mpls-lsp- hierarchy
11 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net MS-PW TE Potential Protocols Use PWE3 encaps/forwarding All the machinery for MS- PW TE exists PW endpoint identifier and control word bit are a missing piece Use PWE3 encaps/forwarding SS-PW Signaling exists TE is a missing piece Explicit Routing QoS Signaling Make-before-break Fast-reroute… RSVP-TE LDP
12 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Misconceptions RSVP-TE doesn’t support targeted signaling It does – Look at LSP-Hierarchy RSVP-TE doesn’t have reliability support No. Look at RSVP reliable messaging in RFC 2961 RSVP-TE is not scalable Compare targeted RSVP-TE signaling with targeted LDP sessions PW signaling with either protocol requires the same information to be signaled, and the same amount of state to be maintained Scalability is determined by the state required to setup a MS-PW and the overhead required to maintain the state. So let us focus on the relevant question – Are there really valid reasons to not use RSVP-TE for MS-PW TE signaling?
13 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Discussion Assertion – LDP and L2TPv3 are the only protocols supported by PWE3 and hence MS-PWs must be setup using only these True today, doesn’t have to be always the case Requirements for MS-PW are different from SS-PWs, specifically for MS-PW TE [Hence the MS-PW requirements effort] So why can’t there be potentially different solutions for MS-PWs – specifically for MS-PW TE ? Requirements/Solution Evolution CCC SS-PWs LDP SS-PWs L2TPv3->(MS-PW, MS-PW TE) RSVP-TE MS-PWs use existing PWE3 encapsulation/data plane architecture
14 Copyright © 2004 Juniper Networks, Inc. Proprietary and Confidentialwww.juniper.net Discussion… There are SPs with SS-PWs who see a reason to deploy a different technology for MS-PW TE – namely RSVP-TE There are multiple vendors who want to implement it There are no substantive technical issues with it SPs that deploy RSVP-TE for FRR and/or QoS will want the same features for MS-PWs Operational ease is a bonus PWE3 must look at the big picture and address all elements of MS-PW TE MS-PWs and PW TE and PW Resiliency A piece meal approach would be short-sighted