1 / 7

Supporting IP Multicast over VPLS draft-serbest-l2vpn-vpls-mcast-02.txt

Supporting IP Multicast over VPLS draft-serbest-l2vpn-vpls-mcast-02.txt. Suresh Boddapati Venu Hemige Sunil Khandekar Vach Kompella Marc Lasserre Rob Nath Ray Qiu Yetik Serbest. Problem Definition. Objective Do not send traffic to sites without receivers

denver
Download Presentation

Supporting IP Multicast over VPLS draft-serbest-l2vpn-vpls-mcast-02.txt

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Supporting IP Multicast over VPLSdraft-serbest-l2vpn-vpls-mcast-02.txt Suresh Boddapati Venu Hemige Sunil Khandekar Vach Kompella Marc Lasserre Rob Nath Ray Qiu Yetik Serbest

  2. Problem Definition • Objective • Do not send traffic to sites without receivers • Keep core P routers stateless (Multicast) • Reduce BW waste • Constraints • In VPLS, ingress replication is required • Note: There is no layer-3 adjacency (e.g., PIM) between a CE and a PE

  3. Comments Addressed in v02 • Comment: Snooping at PWs overwhelms PEs • IGMP snooping • Proposal: PEs to do IGMP proxy • PIM Snooping • Proxy behavior is used with PIM snooping on the PEs to reduce the amount of PIM traffic forwarded upstream • The ideal solution would be for the C-Routers implementing PIM-refresh reduction. But at least in the near-term, providers cannot rely on C-routers to have this feature. • Proposal: Rate limit the PIM JP and Hello refresh messages at down stream PEs • Some details on the next slide • Is employed only when PIM-refresh reduction is inactive. • Is fairly light-weight and simple. • The idea here is to send out the Hello/JP messages less frequently (definable by certain parameters and changing the Holddown timer) to ease the burden of PIM snooping on upstream PEs • PIM-refresh reduction should be friendly to PIM snooping, otherwise, PIM Snooping will not work when refresh reduction is active.

  4. Comments Addressed in v02 (Cont.) • Proposal to overcome the burden of PIM Snooping in the core • The PEs are configured to not exceed a threshold (tx_threshold) which represents the aggregate amount of PIM refresh traffic that can be generated in the core • For every PIM JP PDU received by a PE from the access side, the PE will modify the holdtime to a large value (possibly even infinity) before sending out into the core • The holdtime, call it “core_holdtime”, can be configured OR can be adaptively computed based on the number of entries the PE has. • So the refresh rate is roughly 1/3rd the core_holdtime. • The PE will forward refreshes that it receives from the access side into the core only if the refresh timer has expired. Otherwise, it is simply dropped. • To take care of the possibility of JP PDUs getting lost, a robustness variable R (like in IGMP) is configured for the VPLS instance (possibly even per PW). This simply means that the PE will propagate the initial Joins R times into the core instead of only once.

  5. Comments Addressed in v02 (Cont.) • Comment: Should include IPv6 considerations • Done. • Comment: Should elaborate the cases where both IGMP and PIM snooping are necessary • Defined/Included macros • Included data forwarding rules accordingly • Comment: What if uni-directional tree is used for VPLS instead of full-mesh PWs? BIDIR-PIM snooping will have problems. • Out of scope. Current VPLS uses full-mesh PWs.

  6. Additions in v02 • Defined an LDP TLV to flush snooping state to solve duplicate traffic situations • To trigger Assert mechanism

  7. Next Steps • Please comment • WG document?

More Related