[c-nsp] IPTV and MPLS

[Asbjorn Hojmark - Lists]

> SSM is one of the things I was looking at. Out STB's do not 
> support it as far as I know.

No, nothing much supports IGMPv3 today, but you can use static
or DNS maps with SSM.

> The static IGMP joins would mean that all the channels are 
> always provided on the network.

Yes, but that's typically probably perfectly fine, if one is a
content provider.

Also, you can use it to reduce zapping time because you don't
have to wait for a PIM join to cross your network and all of the
routers to build state. It may well make sense to do it at least
for a few 'important' channels, even if you 'only' have to feed
your own STBs.

> Is your SSM static type mappings?

I've done both. For many groups, many changes and/or many boxes,
I prefer using DNS. Your DNS gets (even more) vital, though.

Statics are fine though for few groups and few changes.

> I was looking at it as a way to make sure another source did 
> not show up on our network with the same multicast address as
> one of our channels and screw up that channel.

Well, SSM is one way to fix that. 

-A