[c-nsp] Multicast Core

[Adrian Minta]

Tony Bunce wrote:
> I'm looking for a router to sit at the core of a small-ish multicast network (about 100 sources and receivers total, but would expect it to double over time).  Currently all of the sources and receivers are in the same VLAN but we would like for the occasional receiver to be located in  a different vlan.  We are currently using 2960Gs with IGMP querier enabled; which works but that doesn't look like it is going to scale well.  It looks like the switch sends ALL multicast data to the mrouter port so we are going to need something that can handle all the traffic (probably around 4Gbps), so even if we only need to route 1 20Mbps stream to a different vlan the router has to receive all 4Gbps of traffic.
>
> Does anyone have any recommendations for this scenario? I'm thinking a 4948 or 3750G would work.
>   
You will need a router in the path. The router need to support only the 
bandwith summ of all the multicast sources multiply with the number of 
vlans ( worst case scenario) . Dowstream switches will do the 
replication of pachets.

3750G will not handle this becase multicast routing is done in CPU. I 
believe the first switch that do multicast routing in hardware is 6500.

If all the multicast streams multiply by the number of vlans is bellow 
1Gbps  a "soft" router like 7200NPE G1 will do the job.