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New Member

Design issue--Centralized Call Manager

I am designing a centralized Call Manager solution at 3rd party location where no RTP calls will terminate. However, I must still allocate a certain amount of bandwidth for call setup/teardown. For 100 concurrent calls, how much "signaling" bandwidth should be allocated for this 3rd party site? Is RTP traffic actually routed through the Call Manager such that I would need to count # of calls x 2 (in/out)?

New Member

Re: Design issue--Centralized Call Manager

Keep in mind that signaling traffic doesn't have a direct relationship to how many concurrent calls are in progress but rather how many call attempts (BHCA) are placed during a time period. The default model recommends no more than 33% of the link should be real time traffic and no more than 5% should be signaling. Those numbers however need to be looked at on a case by case basis.

What kind of link do you have between the remote site and the site w/ the CallManager? How many phones are at the remote site? What's the nature of the business; ie: call center or mom and pop shop?

As for RTP streams from the CallManager, the CallManager normally does not terminate the RTP stream between to IP devices. There are some conditions where this may occur:

1) Using the CallManager as a xcoder

2) Using the CallManager as a conf bridge

3) Music on Hold etc etc

Hope this helps.

New Member

Re: Design issue--Centralized Call Manager

Thanks for your reply. To answer your questions--the link will be IP over FR ATM SIW PVC. Business is typical corporate enterprise traffic--Fortune 1000. Call volume is reasonably low right now since this is Phase 1 of the rollout plan. Thus, 100 concurrent calls are expected at the CCM.