PIM Snooping in VPLS draft-hemige-serbest-l2vpn-vpls-pim-snooping-01.txt

1
PIM Snooping in VPLSdraft-hemige-serbest-l2vpn-vp
ls-pim-snooping-01.txt

• Yetik Serbest
• Venu Hemige
• Ray Qiu
• Suresh Boddapati

2
Background

• Previous revision presented in Vancouver
• Specified procedures for PIM-Snooping.
• It required Join-Suppression to be disabled in
  the CE routers to provide transparent LAN
  services.
• Disabling of Join Suppression is not supported in
  many existing routers.
• Operational complexity of deployment high if we
  require CEs to disable Join Suppression.

3
Recommendations at Vancouver

• Operational transparency more important - Not to
  place any requirements on CEs.
• To make VPLS multicast work even when Join
  Suppression is enabled in the VPLS.
• PIM Proxy scales much better, so it is a better
  trade-off over LAN transparency.
• Both PIM Snooping and PIM Proxy procedures are
  required.

4
Updates in this Revision

• Addressed detailed comments and feedback from
  Yiqun and Ali. Thanks!
• Specified procedures for both PIM Snooping and
  PIM Proxy.
• Re-organized the draft more readable now.
• PIM Snooping and PIM Proxy procedures are mostly
  very similar.

5
PIM-Snooping
R2
R1
PE1 and PE2 flood the Join(S,G). No snooping on
PWs.
PE2
PE1
PE3 also sends Join(S,G) via LDP
PE3 snoops Join(S,G) while flooding it.
PE3
PW AC Join sent via LDP PIM Join Data Traffic
R4 sends Join(S,G) with R2 as RPF.
R4
R3
6
PIM-Proxy
R2
R1
PE2 originates PIM Join(S,G) to R2.
PE2
PE1
Data traffic forwarded along snooped path.
PE3 sends Join(S,G) via LDP towards R2.
PE3 consumes Join(S,G) without flooding it.
PE3
PW AC Join sent via LDP PIM Join Data Traffic
R3 sends Join(S,G) to R2.
R4 sends Join(S,G) with R2 as RPF.
R4
R3
7
PIM Snooping vs Proxy Compared

• Snooping provides LAN transparency
• Requires Join suppression to be disabled.
• Snoop on Hello and Join/Prune packets.

• Proxy provides operational transparency.
• Works best when Join suppression is enabled.
• Snoop on Hello packets, but proxy Join/Prune
  packets
• Scales much better

8
Solution complexity

• Snooping / Proxy procedures are very similar to
  that of a PIM router.
• Complexity limited to handling of Hello and
  Join/Prune messages.
• Proposed solution provides complete separation of
  control and data planes for both PIM-SM and
  PIM-BIDIR snooping.
• Snooping and Proxy together provide a solution
  that should be easy to deploy.

9
Next Steps

• PIM-Snooping on ACs is important to make VPLS
  Multicast work.
• This solution is needed to solve Issue A
  specified in the requirements draft.
• Some additional feedback received offline need to
  be addressed - some editorial and one relating to
  bi-dir pim.
• The solution specified here is fairly in good
  shape and we would like it adopted as WG document.