[c-nsp] Multicast Reporting......

[Dale W. Carder]

Thus spake Phil Mayers (p.mayers at imperial.ac.uk) on Fri, May 09, 2014 at 06:20:39PM +0100:
> On 09/05/2014 16:26, Scott Voll wrote:
> >OK so we are moving from a Unicast to Multicast video stream and we have
> >been reporting on how many people are watching the stream.  as we move this
> >to a multicast stream how do I report on how many people are watching?
> >
> >Are there package apps that will do this?  the only thing I can think to do
> >is run through every switch and see if it's receiving the stream and try to
> >sparse out the numbers.
> >
> >There has to be a better way
> 
> Depends on the network topology and devices.
> 
> e.g. In our network, multicast receivers have cat6k as the last-hop
> egress router, and routed interfaces are SVIs. In this config, you
> can run:
> 
> sh ip igmp snooping statistics [int VlanX]
> 
> ...which shows something like what you want:
> 
> Source/Group        Interface   Reporter     Uptime Last-Join Last-Leave
> 0.0.0.0/239.a.b.c   VlX:GiX/Y   192.0.2.28   4w0d   4w0d          -
> 
> The absolute furthest "up" (towards the source) you might gather ths
> info is the last-hop router(s) for all the receiver(s) as hops
> further upstream just don't see receiver activity, only aggregated
> joins.
> 
> Obviously layer2 devices downstream of the last-hop router will see
> it and may or may not give you this info.
> 
> A totally different approach is to have the receiver report back via
> RTCP or similar, but obviously that requires client-side software
> support.

Multicast quicktime clients can report back to a quicktime server, though 
I've not not looked at how they do this.

Dale