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Multi-hop Pseudowire Setup and Maintenance using LDP draft-balus-mh-pw-control-protocol-00.txt

Multi-hop Pseudowire Setup and Maintenance using LDP draft-balus-mh-pw-control-protocol-00.txt. David McDysan, MCI Florin Balus, Nortel. Challenges LDP Session Scaling PSN Tunnel Scaling PSN Interoperability Control Interoperability Authentication Discovery TE & QoS Support.

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Multi-hop Pseudowire Setup and Maintenance using LDP draft-balus-mh-pw-control-protocol-00.txt

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

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

  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

  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: • Dynamic MH-PW setup and maintenance • Single or Double sided end to end provisioning

  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?

  6. Operational Consistency – Service ManagementPWID Example Pseudo-Wires Setup and Maintenance • Defined in draft-ietf-pwe3-control-protocol 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 PW U-PE1, PWID=40, U-PE2 (U-)PE1 (U-)PE2 P (LSR) LDP Session Virtual Forwarder S-PE2 S-PE3 MH PW U-PE1, PWID=40, U-PE2

  7. MH-PW Setup & Maintenance - Provisioning Models • 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 Same Provisioning procedures, options: e.g. double, single sided provisioning PW 40 40 U-PE1 S-PE1 S-PE2 U-PE2 P AC11 AC21 40 40 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

  8. 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 New PW Signaling Element – MH PW TLV LDP Label Mapping Message PWid & GID FEC TLV Label TLV Other Optional TLVs • MH PW TLV • Source U-PE • Destination U-PE New TLV • TLV inserted by the originating U-PE • Prefix Format (L3FEC) proposed for all internal fields

  9. 4. On receipt of the LM: use destination U-PE to find the next signaling hop. 22. 30. 3. U-PE1 builds LM & forwards to S-PE1 5. S-PE1 builds new LM & forwards to U-PE2 6. On receipt of the LM: check Destination U-PE = itself. Verify Source Address against provisioned Destination U-PE. PW FEC TLV 40 PW FEC TLV 40 Label TLV Label TLV 30 22 Source U-PE Source U-PE U-PE1 U-PE1 MH PW TLV Destination U-PE Destination U-PE U-PE2 U-PE2 MH PWs using End to End LDP Signaling – Operational WalkthroughHighlighting only the Steps Specific to MH PW • 1. Provisioning on U-PE1 • PWID = 40 • Remote PE = U-PE2 • 1b. Provisioning on U-PE2 • PWID = 40 • Remote PE = U-PE1 2. Use destination U-PE to find the next signaling hop. LDP LDP U-PE2 U-PE1 S-PE1 P P

  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

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