CCM 4.1 and Gatekeeper CAC

[n.clark]

I am using a gatekeeper to manage call admission control between CCM and CME. I have a Call Manager cluster in one zone and CME in another. I am limiting the interzone bandwidth for the CME zone, no limit on the CCM zone. Calls from CME phones seem to be requiring 16kbps per call (per the show gatekeeper zone status command) if I limit the bandwidth to 16 I can only place one call, 32 two calls etc. But from the Call Manager I can't place any calls to the CME zone unless I bump the bandwidth to 128. I can't seem to find any documentation on how much bandwidth a CCM (g.729) call requires vs a CME (g.729) call. Any help would be appreciated.

[n.clark]

Here is what I am observing for calls from CCM phones to CME phones (the codecs everywhere are g.729):

Prior to any calls:

Gatekeeper01#sho gatekeeper zone stat

GATEKEEPER ZONES

================

GK name Domain Name RAS Address PORT FLAGS

------- ----------- ----------- ----- -----

LS000 lesschwab.com 10.100.0.44 1719 LS

BANDWIDTH INFORMATION (kbps) :

Maximum total bandwidth : unlimited

Current total bandwidth : 0

Maximum interzone bandwidth : 128

Current interzone bandwidth : 0

Maximum session bandwidth : unlimited

When a call is being setup (ringing) from the Call Manager to the CME, notice the 128 current bandwidth:

Gatekeeper01#sho gatekeeper zone stat

GATEKEEPER ZONES

================

GK name Domain Name RAS Address PORT FLAGS

------- ----------- ----------- ----- -----

LS000 lesschwab.com 10.100.0.44 1719 LS

BANDWIDTH INFORMATION (kbps) :

Maximum total bandwidth : unlimited

Current total bandwidth : 128

Maximum interzone bandwidth : 128

Current interzone bandwidth : 128

Maximum session bandwidth : unlimited

Total number of concurrent calls : 1

After the call is answered, notice that the current bandwidth drops to 16:

Gatekeeper01#sho gatekeeper zone stat

GATEKEEPER ZONES

================

GK name Domain Name RAS Address PORT FLAGS

------- ----------- ----------- ----- -----

LS000 lesschwab.com 10.100.0.44 1719 LS

BANDWIDTH INFORMATION (kbps) :

Maximum total bandwidth : unlimited

Current total bandwidth : 16

Maximum interzone bandwidth : 128

Current interzone bandwidth : 16

Maximum session bandwidth : unlimited

Total number of concurrent calls : 1

[palves]

I find it strange you are having this problem.

I've tried the above using 3.3(4) and don't have the same problem. Yeah, I know that's a different version.

CCM and CME both use 16kbps for G.729 calls.

Have you tried just using CM and CME within a single zone for troubleshooting's sake?

Also, do a SHOW CALL ACTIVE VOICE BRIEF on CME to make sure it's using G.729.

Paul

[sbeukenkamp]

It is most likely a BRQ issue. During the initial Addmission Request phase the CME requests 128k of bandwidth from the GK . When the call is setup, BRQ is used to down negotiate the Bandwidth to 16k.

This is an issue. CME should not request 128k for an g729 call.

[palves]

The calls are the other way around. The BRQ is relevant only if an ip phone on CME makes the call (or originates from CME). Then you need to set the BRQ parameter in the CM Service to TRUE.

However, if you read the original post you'll notice the call is originating from CCM not CME.

Paul