L2VPN%20Provisioning%20

1
L2VPN Provisioning Signaling

• draft-ietf-l2vpn-signaling-04.txt

Eric Rosen Wei Luo Bruce Davie Cisco Systems
Vasile Radoaca Westridge Networks
2
The story so far

• Prior versions of this draft describe modular
  approach to provisioning, discovery and signaling
  for L2VPNs
• VPWS, VPLS (hierarchical, distributed, and
  vanilla)
• LDP- L2TPv3-based signaling
• BGP-based autodiscovery
• Other autodiscovery methods possible
• -03 version covered inter-AS issues

3
Changes from -03 version

• Fixed issue with Distributed VPLS advertisement
• Provision a VSI_ID per U-PE at N-PE
• Advertise one NLRI per N-PE
• Modelled on BGP-VPLS draft
• Addressed comments on list
• See next slide
• Clarified use of PE address in VSI identifier
• Just a convenience, not requirement
• Added IANA considerations

4
Comments on -03

• Note that the specific structure of AGI AII
  speced here may affect other uses of PW
  signalling
• Note the scaling impact of advertising individual
  forwarders
• Clarify the provisioning of Acs
• 3.5.4 conflicts with PW-SWITCH
• Trimmed section dramatically

5
Comments on -03 (cont.)

• Discuss co-ordination of RD and RT assignment
  among ASes
• Note that inter-AS model depends on BGP support
  by PEs
• Explain how route selection among multiple ASBRs
  is done
• Note that ASBR resiliency is provided by BGP (at
  corresponding timescale)
• Note that ASBRs and SPEs are co-located
• Editorial comments addressed
• New ASCII art to illustrate D-VPLS

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Summary

• All comments since Minneapolis have been
  addressed
• WG last call for this draft?

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Multi-AS tunnel LSP model
AC 3
AC 1
PE-3
PE-1
AS 1
AS 2
ASBR-2
ASBR-1
PE-2
PE-4
AC 4
AC 6
Tunnel LSP
Attachment circuit
Attachment circuit
pseudo-wire
LDP
Auto-discovery (MP-iBGP)
Auto-discovery (MP-iBGP)
Auto-discovery (MP-eBGP)

• PE-PE LSP is built as per RFC 2547, option (c)
• Addresses of PEs labels carried in BGP
• PW signaling from PE-PE

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Pseudo-wire "switching" model
AC 3
AC 1
ASBR-2
ASBR-1
PE-3
pwid 34
PE-1
pwid 78
pwid 111
AS 1
AS 2
PE-2
PE-4
AC 4
AC 6
Pseudowire
Pseudowire
Pseudowire
Attachment circuit
Attachment circuit
LDP / L2TPv3
LDP / L2TPv3
LDP / L2TPv3
Auto-discovery (MP-iBGP)
Auto-discovery (MP-iBGP)
Auto-discovery (MP-eBGP)

• Autodiscovery analogous to L3VPN Model (b) - eBGP
  used between ASBRs
• Limiting PW signaling to ASBRs gives control over
  policy and avoids mesh of PE-PE signaling

draft-martini-pwe3-pw-switching-01.txt
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BGP Autodiscovery

• VPLS BGP advertisement for a particular VSI at a
  given PE will contain
• an NLRI of AFI L2VPN1, SAFI TBD2, encoded as
  RDPE_addr
• a BGP next hop equal to the loopback address of
  the PE
• extended community attribute containing one or
  more RTs
• VPWS BGP advertisement for a pool of attachment
  circuits at a given PE will contain
• an NLRI of AFI L2VPN1, SAFI TBD2, encoded as
  RDpool_num
• a BGP next hop equal to the loopback address of
  the PE
• extended community attribute containing one or
  more RTs

1. Same for all L2VPN schemes (e.g. vpls-bgp)2.
Same value for both cases in this draft