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

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

• David McDysan, MCI
• Florin Balus, Nortel

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MH PW Challenges Solutions
Inter-provider Use Case
Service Provider 1
Service Provider 2
Metro Access Interconnection Use Case
Backbone
Metro Access 1
Metro Access 2
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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

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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

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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?

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Operational Consistency Service ManagementPWID
Example

• Pseudo-Wires Setup and Maintenance
• Defined in draft-ietf-pwe3-control-protocol

PW
U-PE1, PWID40, U-PE2
(U-)PE1
(U-)PE2
P (LSR)
LDP Session
Virtual Forwarder
S-PE2
S-PE3
MH PW
U-PE1, PWID40, 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

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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

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

• Same Provisioning procedures, options e.g.
  double, single sided provisioning

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New PW Signaling Element MH PW TLV
LDP Label Mapping Message
FEC TLV
PWid GID
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

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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
S-PE1
U-PE1
P
P
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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