Multi-Segment%20Pseudowire%20Setup%20

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Multi-Segment Pseudowire Setup Maintenance
using LDPdraft-balus-mh-pw-control-protocol-02.tx
t
Authors David McDysan (MCI), Mike Duckett
(Bellsouth), Yeongil Seo (Korea
Telecom), Yuichiro Wada (NTT Communications)
Andy Malis (Tellabs), Chris Metz (Cisco),
Paul Doolan (Mangrove), Ping Pan
(Hammerhead), Prayson Pate (Overture), Vasile
Radoaca (Consultant) Florin Balus, Mike Loomis,
Jeff Sugimoto (Nortel)
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Key Principles draft-balus-mh-pw

• Develop MS-PW Solution as a Super Set of SS-PW
  procedures
• SS-PW, VPLS Implementations, Deployments based on
  LDP Signaling
• Re-use Signaling Procedures, Current Addressing
• Operational Consistency, Familiarity with SS-PWs
• Same Service Management, Provisioning Models...
• OSS Touches at only U-PEs
• Add Minimal Changes to satisfy the MS-PW
  Requirements
• Easily applicable to existing LDP-VPLS
  Implementations

Extend existing PW Signaling Protocol
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MS 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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Solution Space

• draft-ietf-pwe3-ms-pw-requirements-00.txt - WG
  document
• draft-ietf-pwe3-control-protocol-17.txt
• Setup and Maintenance for SS PWs Using LDP
• Interoperable Implementations Everywhere,
  Deployed on a fairly Large Scale
• L2VPNs (e.g. LDP-VPLS) use the SS-PW Base
• draft-ietf-pwe3-segmented-pw-00.txt
• Provides Generic Interworking Solution for
  different types of Signaling
• Provides Solutions when Signaling Separation is
  required
• Used to Interconnect MS-PW (draft-balus-mh-pw)
  and L2TPv3 Domains
• draft-balus-mh-pw-control-protocol-02.txt
• Dynamic Creation of MS-PWs Using LDP
• MS-PW is a Super Set of existing SS-PW procedures
  
• Reuses Existing PW Encapsulations, Information
  Model and Signaling
• Re-usable Transparently by Existing L2VPN
  Implementations (e.g. LDP-VPLS)

Common Signaling Procedures for both SS MS-PWs
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MS PW Requirements Addressed

• Dynamic Creation of MS-PW
• IP addressing but encoding supports other address
  types (e.g., NSAP, IPv6)
• Same Forward and Reverse Path
• Automatic Determination of intermediate S-PEs
• S-PE_hop-by-S-PE_hop selection based on regular
  IP Routing Procedures
• Minimal OSS touches - at only U-PE(s)
• Supports A/D, single or double sided provisioning
  as per draft-ietf-l2vpn-signaling
• Operational Consistency with SS-PW
• Support for both L2FECs
• Signaling of Quantity and Quality of Service
• Resiliency Procedures
• Supports OAM capability negotiation

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MS-PW Operational Consistency with SS-PWsRe-use
of Existing Information Model, OAM Procedures for
SS-PW
Service Provisioning Service Instance (AGI,
SAII, TAII) Remote Peer PE Loopback
PW
LDP
PE 1
PE 2
VF
VF
U-PE 1
U-PE 2
S-PE
SP
VF
VF
MS PW
LDP
LDP
Service Provisioning Service Instance (AGI,
SAII, TAII) Remote Peer U-PE Loopback
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PW Information Model PW Control
LDP
PE 1
PE 2
VFx
VFy

• Unique Endpoint ID
• Prefix 1, AI x PW Ctrl

• Unique Endpoint ID
• Prefix 2, AI y PW Ctrl

Originator PE Destination PE is one E-LDP hop
away Receiving PE Source U-PE Prefix derived
from local E-LDP Session
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MS-PW Information Model
SS-PW
SS-PW
U-PE 1
S-PE
U-PE 2
SP
VFx
VFy
S-PE
LDP
LDP
Originator (U-)PE Destination PE is more than
one E-LDP hop away Receiving NE Source (U-)PE
Prefix can not be derived from local LDP
Session Solution U-PE Prefixes to be carried in
the Signaling Messages
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How to carry sU-PE, dU-PE Prefixes?Two
possibilities, orthogonal to the procedures
described in the draft
1. Use the Generalized ID - PW FEC 129 Complete
Address Information in one TLV
FEC TLV
Label TLV

• Source U-PE Prefix Identifies the Originating
  U-PE
• Allows peer discovery or verification
• Destination U-PE Prefix Identifies the Remote
  U-PE
• Enables S-PE to automatically determine Next PW
  Segment

Other TLVs .
MS PW TLV
1. Use a Separate MS-PW TLV Accommodates also PW
FEC 128 (PWID) Implementations
Ready to mandate implementation of PW FEC 129 for
MS-PWs? Ready to start assigning AII Types see
draft-metz-aii-aggregate?
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MS PWs using E2E LDP Signaling Operational
WalkthroughHighlighting only the Steps Specific
to MS PW

• 1b. U-PE2 is provisioned with
• AGI 40, SAII100, TAII200
• Destination PE IP1

• 1. U-PE1 is provisioned with
• AGI 40, SAII100, TAII200
• Destination PE IP2

6. On receipt of the LM check Destination U-PE
itself. Verify Source Address against
provisioned Destination U-PE.
2. U-PE1 Use dU-PE to find next signaling hop.
U-PE2
S-PE1
U-PE1
P
P
P
LDP2
LDP1
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Related Procedures

• Determining Next Signaling Hop
• Static Provisioning - Default Gateway/Summarized
  Prefixes
• BGP AD - See L2VPN SIGN Procedures for
  LDP-VPLS
• QoS TLVs may be included in the Signaling Message
• TSPEC format for Quantity Of Service, DiffServ
  TLV for Quality of Service
• CAC Executed Against the Tunnel to Originator of
  the Local LDP Session
• Resiliency
• Re-routing around Failure
• OAM Negotiation
• End-to-end Capability Negotiation between U-PEs
  VCCV Ping, BFD

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Next Steps

• Do we still need support in the Information Model
  for PW FEC 128?
• PW Protection Options (e.g. 11)

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Summary draft-balus-mh-pw

• Addresses the Signaling Requirements for MS-PWs
• MS-PW Solution as a Super Set of SS-PW Procedures
  
• Operational Consistency, Familiarity with SS-PWs
• Minimal Changes to Existing PW Signaling
• Easily Applicable to existing LDP-VPLS
  Implementations

Make it a WG Draft