PG 1 Multi-hop Pseudowire Setup and Maintenance using LDP draft-balus-mh-pw-control-protocol-00.txt David McDysan, MCI Florin Balus, Nortel

PG 2 U-PE MH PW Challenges & Solutions Inter-provider Use Case U-PE Metro Access Interconnection Use Case Backbone Service Provider 1Service Provider 2 Metro Access 1 Metro Access 2 U-PE Challenges LDP Session Scaling PSN Tunnel Scaling PSN Interoperability Control Interoperability Authentication Discovery TE & QoS Support S-PE Solutions Switching PE (S-PE) Limit Meshes to Hierarchical Level Convert/Authenticate at Hierarchical Boundaries BGP+ Distribution RADIUS+ Discovery & Authentication RSVP-TE+ & PW-LDP+

PG 3 MH PW Requirements Addressed >Dynamic creation of MH PW using IP addressing Encoding supports other address types (e.g., NSAP) >Automatic determination of intermediate S-PEs based upon IP routing S-PE_hop-by-S-PE_hop routing >Minimal OSS “touches” at only U-PE(s) Supports single (or double) sided provisioning >Supports OAM capability negotiation >Operational consistency with SH PW

PG 4 Solution Space >draft-martini-pwe3-pw-switching LDP based solution Provides generic solutions for different PSN types Provides solutions when signaling separation is required >draft-balus-mh-pw-control LDP based, complementary solution with draft-martini-pwe3-pw-switching Extends solution when signaling separation is not required to provide: 1.Dynamic MH-PW setup and maintenance 2.Single or Double sided end to end provisioning

PG 5 MH PW Requirements Not (Yet) Addressed >Quantity and Quality of Service signaling, admission control >MH PW Resiliency >Do we need specific procedures for handling explicit routing of intermediate S-PE in LDP? Need to agree/complete requirements E.g., is there a need for option to traverse same set of S-PEs in each direction?

PG 6 Operational Consistency – Service Management PWID Example P (LSR) (U-)PE1 S-PE2 (U-)PE2 S-PE3 U-PE1, PWID=40, U-PE2 Multi-Hop Pseudo-Wires Setup and Maintenance Defined in draft-balus-mh-pw-control-00.txt End to end service entity Same Service Identification with regular PWs Supports both PWID and Generalized ID FECs LDP Session Virtual Forwarder U-PE1, PWID=40, U-PE2 PW MH PW Pseudo-Wires Setup and Maintenance Defined in draft-ietf-pwe3-control-protocol

PG 7 MH-PW Setup & Maintenance - Provisioning Models U-PE1S-PE1S-PE2 AC 11 P AC U-PE2 Same Provisioning procedures, options: e.g. double, single sided provisioning 1b. U-PE2 is provisioned with PWID = 40 Remote PE IP = U-PE1 MH PW 1. U-PE1 is provisioned with PWID = 40 Remote PE IP = U-PE2 1b. U-PE2 is provisioned with PWID = 40 Remote PE IP =U-PE1 1. U-PE1 is provisioned with PWID = 40 Remote PE IP = U-PE2 40 PW

PG 8 New PW Signaling Element – MH PW TLV FEC TLV Label TLV Other Optional TLVs MH PW TLV Source U-PE Destination U-PE New TLV PWid & GID TLV inserted by the originating U-PE Prefix Format (L3FEC) proposed for all internal fields MH PW TLV Addresses the requirement for dynamic signaling of the MH PW Identifies the LDP message as a multi-hop PW Enables consistent usage of PWID FEC Source U-PE Field - Identifies the originating U-PE. U-PE Peer Discovery or Verification Destination U-PE field - Identifies the remote U-PE Controls propagation of the signaling messages Provisioned or Auto-discovered LDP Label Mapping Message

PG 9 MH PWs using End to End LDP Signaling – Operational Walkthrough Highlighting only the Steps Specific to MH PW P LDP On receipt of the LM: check Destination U-PE = itself. Verify Source Address against provisioned Destination U-PE. S-PE 1 U-PE 2 U-PE 1 4. On receipt of the LM: use destination U-PE to find the next signaling hop. LDP 3. U-PE1 builds LM & forwards to S- PE1 Source U-PE PW FEC TLV Label TLV Destination U-PE U-PE1 U-PE MH PW TLV P 1b. Provisioning on U- PE2 PWID = 40 Remote PE = U-PE1 1. Provisioning on U-PE1 PWID = 40 Remote PE = U-PE2 U-PE2 U-PE Source U-PE PW FEC TLV Label TLV Destination U-PE 5. S-PE1 builds new LM & forwards to U-PE2 2. Use destination U-PE to find the next signaling hop.

PG 10 Next Steps >Agree where the MH PW Signaling Formats and Procedures should be performed: PWE3/L2VPN? i.e. “how do I connect the endpoints/virtual forwarders?” >Complete items not yet addressed >We welcome new contributors to join the effort