I want to deploy muticasr on VPLS, can you all tell me, wthether is it possible and also what are the design and implementation considerations i should have??
There isnt anything like EoMPLS or VPLS support for multicast till now, as the PW VC are transaparent to the traffic being switched through them and the endpoints maintain the state what is to be sent on a PW.
Having said that, the forwarding decision are taken by the endpoint based on MAC table formed using the native ethernet method of flooding learning and forwarding.
Lets look at this topology;
Now assume they are plain switches connected using normal ethernet ports and fibre/copper.
Now if we enable igmp snooping and start multicst traffic from SW1 to a receiver in SW2, then
first it would be flooded on interface connecting to both SW2 and SW3 from SW1.
Once the receiver state is dicovered and the outgoing interface is known as interface
connecting to SW2 the interface towards SW3 is pruned. and it will no more be flooded
across that interface for that group.
Now in VPLS these interconnecting interfaces are replaced by PW. so you have logical connection
between SW1 to SW2 and SW3. And also PE endpoints cannot maintain multicast state in relation to PW VC till now.
The working group on this VPLS draft is considering this aspect for introducing snooping or multicast state maintainence in relation ot PW VC's. till then it will be conisdered as unknwon and flooded across all the neighbors on a VPLS VFI instance.
So if you deploy Mcast on VPLS, it will be broadcasted across the connecting PW VC's,
to atleast make it scale you can thing of having a HUB-n-Spoke VPLS between the source
and destination. If you are trying to dpeloy such multicast over for a Metro-E Access clouds seperated over through MPLS cloud.