I would take a look at the presentation in the other post, there are multitude of ways it can be accomplished and some of those are spelled out in the DOCSIS 3.0 specs. Like the other poster said, HFC architectures are very centralized and controlled at the head-end and the components in the field such as the fiber node and even the CM are not active in making decisions about where traffic goes, they just receive what has been sent to them and pass it along. Ultimately any multicast streams will go to a set-top box (or some other video device) and in the case of dynamic multicast it would be the STB generating the IGMP joins. But to answer your question, the answer is yes, the same stream can be sent to two different receivers in the same service group. By the time it gets to the fiber node, it's just RF and if the CM is tuned to the right frequencies, either a specific one for video, or a shared one, it can be used. Most providers aren't doing IP video over DOCSIS, they are still using QAM based delivery via dedicated video spectrum. Phil On 11/29/13, 9:32 AM, "mr. s" <sigasecure@gmail.com> wrote:
To Those Who Do DOCSIS3.0,
I can't seem to find a simple answer to this, possibly because it is self evident to those actually using Multicast over DOCSIS. Which we are not currently.
Multicast over DOCSIS 3.0, to 3.0 CM, can the CM share the same media stream on their node?
In example, 2 Cable Modems in the same node (no splitting, same US/DS channels/ports, CMTS..), each have a customer watching ESPN.
Is there one or two media streams worth of content on the plant, channels, node?
We now how this operates in other worlds, GPON, xDSL and AE. Just haven't seen it specifically mentioned out right in DOCSIS literature.
Thanks for any direction you have.