Customer MAC Address Flushing for PBB-VPLS

1. Customer MAC Address Flushing for PBB-VPLS Draft-sajassi-l2vpn-pbb-vpls-cmac-flush-00.txt July 28, 2008

2. Authors • Ali Sajassi • Samer Salam • Luyuan • Nabil Bitar • Dinesh Mohan • Raymond Zhang

3. What is it ? • To flush C-MAC addresses in a PBB-VPLS • C-MAC flushing is needed upon AC change – e.g., switch over from primary AC to backup AC • For a dual-homed Customer Equipment (CE) • For a dual-homed Customer Network • It is independent from B-MAC flushing !! (and not be confused by it !!) • It is independent from PW types !! • It is independent from customer network redundancy mechanism • LACP • REP • MSTP, etc.

4. u-PE w/ IB-BEB u-PE w/ IB-BEB PB PB BCB BCB PB PB PE PE P P CE P P PE What is it ? – cont. • Need to solve the issue for: • dual-homed CE or CN • H-VPLS with PBBN access • H-VPLS with MPLS access • H-VPLS with a mix of PBBN & MPLS access MPLS Core Customer Network (802.1Q) Customer Equipment Access Network (802.1ah) Access Network (MPLS) IB- BEB BCB IB- BEB

5. u-PE w/ IB-BEB u-PE w/ IB-BEB PB PB BCB BCB PB PB PE P P P CE P PE PE What is it ? – cont. C-MAC Flushing Scope B-MAC Flushing Scope MPLS Core Customer Network (802.1Q) Customer Equipment Access Network (802.1ah) Access Network (MPLS) IB- BEB BCB IB- BEB

6. Why is it needed ? • If C-MAC addresses are not flushed upon the topology change, then other PE can have incorrect forwarding info resulting in black holing of customer traffic • If nothing is done, then black holing persists till five min timeout for aging C-MAC addresses

7. How does it work ? • Send an Ethernet in-band “flush” message from the I-comp of backup PE or backup BEB for the affected customer (I-SID) • Since the “flush” message is in-band, it is transparent to intermediate PE devices – e.g., it gets treated as data by them • It only gets processed by egress PE devices where the service is terminated (I-SID is terminated)

8. How it works ? – Cont. • The backup I-comp only needs to construct the “flush” message with fixed fields and initiates it from any redundancy mechanism used • No need to run any IEEE protocols (e.g., MIRP, MVRP, or MMRP) • Works for PBB-VPLS with MPLS access network !! • Works for PBB-VPLS with PBBN access network !!

9. u-PE w/ IB-BEB u-PE w/ IB-BEB PB BCB BCB PB PB PB Flush Flush Flush Flush Flush CE PE P PE P P PE P Proc Flush Proc Flush How it works ? – Cont. MPLS Core Customer Network (802.1Q) Customer Equipment Access Network (802.1ah) Access Network (MPLS) IB- BEB BCB IB- BEB

10. Advantages • Fast convergence since the “flush” message is passed through intermediate devices as data • Transparent to all devices operating on B-MAC addresses (e.g., all intermediate devices) • Applies equally well for both intra and inter I-SID domains • No interworking is required when this message is initiated from native 802.1ah network or MPLS access with 802.1ah functionality

11. Next Step • Optimize C-MAC flushing to not only flush C-MAC for the affected customer as proposed currently but also to limit the C-MAC flushing to the affected I-comp for that customer • Solicit comments on the mailing list • Ask for WG status in the next meeting