Multicast or Unicast streams?

[Humph1]

Looking to get Virgin Stream.

However, the subject says it all. I currently subscribe to NowTV which are Unicast streams. This means Sky Sports streams are anywhere from 30s-60s behind the live action.

BT offer NowTV via their BT TV Pro box - but these are streamed as Multicast, meaning they are only approximately 10s behind the live action. A big factor when watching live sports.

Can anyone confirm if the Virgin Media streams on the Stream service are streamed via Multicast or Unicast?

Thanks.

[Roger_Gooner]

This isn't a simplistic either/or. For example BBC does live IP multicast streaming but data packets do get discarded by routers when individual links become congested, so a conventional unicast HTTP in a CDN is used to do recovery and maintain an uninterrupted live stream.

[Humph1]

But surely that's the whole point in why both Virgin and BT require their broadband for their streamed TV service? It's a closed circuit that doesn't traverse the public internet so they can guarantee delivery and priority of their multicast packets. Are there any Virgin employees here who can confirm this? If it's just Unicast over a Virgin network there would be little difference in that versus the NowTV App which is Unicast over the public Internet.