In Bell Canada territory, on the copper, Bell uses 2 VLANs , 35 for data, and I think 36 for IPTV service. Multicast is of course enabled on VLAN 36 and on the IPTV aggregation network back up to the video servers which is separate from the data services. VLAN 35 is set to aggregate to the BRAS router somewhere upstream. Currently, independent ISP traffic is separated at the BRAS and PPPoE packets reach the ISP premises from BRAS via L2TP links. Multicast cannot be handled by this service. One of the proposals is to have ISPs connect at the CO directly into the switch feeding the DSLAMs. ISPs think that they can then do multicast without needing Bell's intervention. My concern is with ISP traffic still needing to pass through at least Bell 2 switches and the DSLAMs before reaching the end user. If ISPs pass through this equipment via a differerent VLAN (lets call it 37), would it just be a simple deal of telling those switches and VLAN to "enable multicast" on that VLAN, or would it require careful configurations to enable specific multicast IPs etc ? Would switches and DSLAMs handle multicast on separate VLANs as totally separate realms so that one need not worry about the other using same multicast IPs ? Or is this untested territory since there nobody ever tried this ? (I assume that on the Australian NBN, NBNCo would assign separate IP ranges to different IPtv providers and traffic would be handled as a single multicast system).