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New Member

Network Music on hold works one way only

I have a call manager at the central location. I have 2 sites (central and remote). I defined the music on hold sever on the call manager, enabled multicasting on the server as well as the routers connecting the 2 siites. Now, when i call from the central site to remote site, i get music on hold over the network, but when i call from remote site to central site, i do not get music on hold.

I created a MRG which included everything and i put it in to a MRGL and applied the list to all the pools, so that all phones (central and remote) could use these resources.

What did i do wrong? i mean the MOH server is only at the central site so everyone has to use it. I put the MOH in default pool.


Re: Network Music on hold works one way only

Rule of thumb is as follows:

- If you are getting tone on hold, something is wrong with your CallManager configuration. MOH Server, MOH Audio Source, MRG, MRGL, whatever.

- If you are getting dead air, you have a multicast/network problem. CallManager thinks it's doing the right thing, hence the lack of tone; the problem is likely the underlying network.

Assuming you are not getting tone on hold (you didn't mention that you were), I would attack this as a multicast/routing problem. Ensure that you are getting IGMP Joins from the phones, and ensure the proper multicast group has been joined all the way up the shared tree.

I have been bitten by a few things in my experiences:

- Lack of "ip pim sparse-mode" on the interface facing the IP Telephones; this often gets overlooked since you don't typically have a need for PIM neighbors here.

- access-list's "protecting" the CallManagers, accidently filtering multicast traffic (not specifically permitted, hence, denied)

- Sometimes your multicast configuration is right, but you forget to specify an RP (or specify the wrong one); typical multicast troubleshooting will help you reveal this

Start at the head end, make sure the first hop sees the CallManagers as valid multicast sources in the proper group, and trace things from there. Somewhere between the non-working phones and the working phones, that group is not joined. Figure out where, and why.

Good luck.

New Member

Re: Network Music on hold works one way only


I forgot to mention that i hear the beap, but, no music, i have configured multicasting everywhere. It appears to be MRG or MRL issue.


New Member

Re: Network Music on hold works one way only

I would like to add that i have 2 regions and 2 locations. One is central and the other one is remote site. If i put the MOH server in central device pool (which has central region in it), i hear MOH when calling from that phone, but, not visa versa.

When i put the MOH in the remote device pool, i can hear MOH when i call from the remote site to the central site and not visa versa.

I have to specify the device pool under the MOH server options otherwise call manager does not like it.

Any suggestions what i should do?

I created 2 MRGs and 2 mrgl's. both the MRG have all the resources that i had available in call manager including MOH(multicast). The i created 2 MRGL and gave priority to Local MRG based upon the site i was configuring it for them i applied the list to the device pools (2, central and remote).

Any help would be highly appreciated.


Re: Network Music on hold works one way only

Check two things:

1)If in MRG configuration you have "Use Multicast for MOH Audio checked"

2) Under Service Parameter for IP Voice Media Streaming Service, you have both g711 and g729 selected as the "Supported MOH Codecs".