Q on MoH

Unanswered Question
Mar 19th, 2007
User Badges:


assume a central site that has CCM 5.x cluster, and remote sites connected to this central site, regarding MoH, how much either the end-user MoH or network MoH consumes BW if a user in remote site requests unicast MoH from CCM in central site, and what is the best practice to preserve BW for MoH in this scenario?

please advise


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Brandon Buffin Mon, 03/19/2007 - 10:35
User Badges:
  • Purple, 4500 points or more

Baically, MOH is just another audio stream just like a phone call. The bandwidth consumed will depend on the codec being used. If you're streaming g.711 MOH, the bandwidth will be 64k plus overhead (CCM uses 80k for CAC calculations). If you're streaming g.729 MOH, the bandwidth will be 8k plus overhead (CCM used 24k for CAC calculations).

One way to avoid MOH streams traversing the WAN is to allow the local gateways to stream multicast MOH to local devices. Take a look at the following link.


Hope this helps. If so, please rate the post.


msulieman Mon, 03/19/2007 - 10:53
User Badges:

thanks for this clarification,

so I can determine either G711 MoH or G729 MoH on WAN link by using the same regions I already used for calls for inter-region G729 and for intra-region G711

is this true?

Brandon Buffin Mon, 03/19/2007 - 10:57
User Badges:
  • Purple, 4500 points or more

Yes that is correct. You will also need to make sure that CCM is set to stream g.711 and g.729 by configuring these codecs under the IP Voice Media Streaming Application Service Parameters or you will need a transcoder in place to do the job.


thisisshanky Mon, 03/19/2007 - 11:00
User Badges:
  • Purple, 4500 points or more

g729 isnt made for music, so you can have degradation in quality of music if you use g729 for music across the wan. Unless you set the service parameter under Cisco IP Voice streaming media service, (select 711 and g729), g729 codec will not be used for MOH.

Brandon already suggested the best solution for wan environments. Use multicast streaming from flash of the remote site router. One catch with this solution is that you can only have one music source defined in the callmanager. Although you can change the moh file in the flash on each remote site router with a different one, if you want different music at different remote sites.



PS: please remember to rate posts!


This Discussion