Solved: VoIP and Multicasting question

news2010a · ‎09-27-2010

Hi,

Imagine a service provider (MPLS) can offer multicast services (total of 10 offices connected via MPLS).

A strrange question:

Imagine one a given VoIP call (a monthly call from the CIO), you deploy "Music On Hold" while people wait on that call. There are 5,000 people listening to such call.

Is the multicast feature going to optimize or assist in the delivery of such call? How about the Music On Hold? is that going to receive any special treatment just because I have mutlicast feature enabled?

In my view if the "Music on Hold" is riding under the VoIP stream, whatever it happens to the VoIP traffic is going be the applied to the Music On Hold.

Just wanted to make sure I am not missing something here before I answer the question to someone.

Giuseppe Larosa · ‎09-28-2010

Hello Marlon,

in order for the speaker to be heard by 5,000 people the audio conference has to be delivered as a multicast session and not as standard VOIP call.

the MUSIC on hold can be a different multicast group or session and so when the use in on hold it has to join the MOH multicast group.

However, as far as I know there are not conference bridges that are able to handle 5,000 users so I see possible for the users to join a multicast session representing the speaker but I don't see possible from a signalling point of view to handle MOH for all the users.

what is possible is to handle user that puts on hold buy joining the MOH and releasing the speaker session

When later the user wants to join again the opposite has to be done.

In any case from a networking point of view if multicast routing is correctly supported it means just to handle two multicast sessions/groups.

Hope to help

Giuseppe

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Giuseppe Larosa · ‎09-28-2010