L2VPN%20Provisioning%20

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L2VPN Provisioning Signaling

• draft-ietf-l2vpn-signaling-03.txt

Eric Rosen Wei Luo Bruce Davie Cisco Systems
Vasile Radoaca Westridge Networks
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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

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Changes from -02 version

• Main change added new section on Inter-AS issues
• Builds on "PW Switching" draft
• This forced some small changes to PW signaling
  procedures for VPLS (3.2.3 and 3.5.1)
• Also added some clarifying text in BGP-based
  autodiscovery sections (3.2.2.1 and 3.3.2.1)

draft-martini-pwe3-pw-switching-01.txt
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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
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Changes to VPLS signaling

• -02 assumed that signaling was PE-PE, therefore
  need only identify the VPLS instance within the
  PE
• AGI VPN-ID, TAII SAII null
• When signaling between ASBRs, need to identify
  the PE as well
• AGI VPN-ID, TAII PE_addr, SAII null
• Note PE_addr is just an identifier, need not be
  routable
• For Dist. VPLS, SAII n - this allows multiple
  PWs from N-PE to N-PE

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Next steps

• draft-ietf-l2vpn-vpls-ldp-xx.txt should change to
  reflect this change (or just reference this
  draft)
• Synchronize with draft-ietf-l3vpn-bgpvn-auto-xx.tx
  t
• WG last call for this draft?