Most ISPs don't allow multicast on their networks, it get filtered. Routers, by default, will filter multicasts / broadcasts. If they're not configured to route multicasts, the stream stops at the ingress interface.
You may be able to get by with a few connections using "SmallCast" which is a unicast to a specific address.
Smallcasts are usually used to get content from one IPTV / Video server to another through an otherwise multicast-hostile network.
Unfortunately, the number of SmallCasts allowed is something like six destinations (per stream?).
Also be aware that since SmallCasts are Unicast, each stream will take one stream's worth of bandwidth (6 streams = 6X the bandwidth of the stream).
You may be able to set up Video-on-Demand (which is also Unicast - see the warning above). To get to the Content Manager, make sure the client is pointing to the server (not relying on a broadcast menu), having a "hosts" entry is not a bad idea (or a DNS record, or both).
If you are serving via Web interface, the Embedded code will point directly to the servers and should work across subnets / networks.
The servers seem to want NETBIOS naming. If you have a WINS server available, see that the servers are configured to use it.
That's all I can think of now ...
Good Luck
Scott
