Supporting%20IP%20Multicast%20over%20VPLS%20draft-serbest-l2vpn-vpls-mcast-01.txt

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Supporting IP Multicast over VPLSdraft-serbest-l2
vpn-vpls-mcast-01.txt

• Suresh Boddapati
• Venu Hemige
• Sunil Khandekar
• Vach Kompella
• Marc Lasserre
• Rob Nath
• Ray Qiu
• Yetik Serbest

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Multicast Traffic over VPLS

• The flooding of a frame occurs when
• The destination MAC address has not been learned
• The destination MAC address is a broadcast
  address
• The destination MAC address is a multicast
  address
• ? Flooding is the solution today

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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

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A Solution

• IGMP and/or PIM Snooping
• Basic idea Snoop IGMP and PIM messages to
  determine which sites to send the traffic to
• Benefits
• Prevents sending multicast traffic to sites with
  no members
• Keeps P routers in the core stateless
• Improves VPLS to support IP multicast more
  efficiently
• SP does not need to perform the tasks to provide
  multicast service (e.g., running PIM, managing
  P-group addresses, managing multicast tunnels)
• SP does not need to maintain PIM adjacencies with
  the customers

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An Application IPTV
DSLAM
VSO
L2-PE
Copper
GigE
VSO
L2-PE
VPLS (IGMP Snooping)
L2-PE
Video
VHO
VSO
SHE
IP/MPLS Backbone with MCAST Support
L2-PE
PE
VSO
Internet
20-25Mbps
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An Application Router Inter-connect with PIM
L2-PE
PIM
Site B
L2-PE
VPLS (PIM Snooping)
L2-PE
PIM
L2-PE
PIM
Site A
L2-PE
Site C
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Issues Addressed in v01

• IGMP Snooping
• Reports are sent to all mcast routers
• MRDP, static conf, PIM Hello Snooping to learn
  mcast routers
• Explicitly stated Holddown timer for IGMP leave
• If a mcast router and a host are connected to a
  CE (layer-2 switch), that layer-2 switch MUST do
  IGMP snooping
• IGMPv3 reports/leaves are elaborated and the
  example is updated accordingly
• PIM Snooping
• To avoid PIM Join Suppression, PIM Joins are
  forwarded to Upstream Neighbor Address

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Duplicate Traffic (PIM-SSM)
PE2
R3
R1
VPLS
PE1
R2
Src
PE3
R4
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Duplicate Traffic (PIM-SM)
PE2
R3
R1
PE1
VPLS
R2
Src
PE3
R4
RP
R5
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Issues Addressed in v01 (cont.)

• Proposal for Duplicate Traffic Problem
• Detect it, and drop the traffic coming from the
  AC/PW which is not associated with Upstream
  Neighbor Address
• Trigger Assert by Flushing (by defining TLV)
  the snooping state
• Directly connected sources
• Need to send traffic to all mcast routers
• May not happen with the current guidelines
• Proposals to detect directly connected sources
• ARP snooping
• Static configuration
• Do not allow it

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Next Steps

• Please comment
• Requirements?