1. L2VPN Provisioning & Signaling
draft-ietf-l2vpn-signaling-03.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

3. 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 ( and )
* draft-martini-pwe3-pw-switching-01.txt

4. Multi-AS tunnel LSP model
AC 1
AC 3
PE-3
PE-1
AS 1
AS 2
ASBR-2
PE-2
ASBR-1
PE-4
AC 4
AC 6
Tunnel LSP
Attachment circuit
Attachment circuit
pseudo-wire
LDP
Auto-discovery
(MP-iBGP)
Auto-discovery
(MP-eBGP)
Auto-discovery
(MP-iBGP)
PE-PE LSP is built as per RFC 2547, option (c)
Addresses of PEs + labels carried in BGP
PW signaling from PE-PE

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

6. BGP Autodiscovery
VPLS: BGP advertisement for a particular VSI at a given PE will contain:
an NLRI of AFI = L2VPN1, SAFI = TBD2, encoded as RD:PE_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 RD:pool_num
1. Same for all L2VPN schemes (e.g. vpls-bgp) 2. Same value for both cases in this draft

7. 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

8. 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.txt
WG last call for this draft?