CCM to H323 GW to GK to CME issue

Unanswered Question
Jul 18th, 2007


I`m a bit lost on a issue that i am experiencing right now.

I have a Callmanager, whos is connected to a h323 GW, that GW is connected to a Gatekeeper, the Gatekeeper has another 2 CME locations connected.

When i dial from a CME site to a CME site (through GK) the destination ip phone rings, and upon answer i have audio.

When i dial from a CME site to the CCM Site (through the GK), the destination phone will ring, and upon answer i have audio.

However, when i call from an IP Phone at the CCM site to a CME site (using the h323 GW and GK), the CME phone will ring, however when i answer the CME Phone, the cme phone produces several beeps (sounds like hold beeps), and the CCM Phone stays on ring out, and drops the call after 10 seconds

now i`ve added the h225 connect passthru, and when i dial now the same happens, however the CCM IP Phone shows connected and still drops the call after 10 seconds.

When i configure a trunk on the CCM to the Gatekeeper, everything works like it should, so it looks like my h323 GW hop is causing some issues.

my guess is that some h225 h245 and probably h450 messages are missing between the h323 GW and the CME`s.

Does anyone have idea?


I have this problem too.
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Brandon Buffin Wed, 07/18/2007 - 04:36

Sounds like a codec issue. Check the codec configured for the H.323 gateway in CCM, the dial peers on the H.323 gateway, and the incoming dial peer on CME. These will need to match or else you will need a transcoder.

Hope this helps.


egoppel Wed, 07/18/2007 - 05:09

I already checked the codecs, they are all matching. so unfortunately this is not the cause.

I also think that if it is a codec issue, the call should drop after answering, and not providing a beep sound to the CME.

m-haddad Fri, 09/28/2007 - 17:19


I am having exactly the same issue. Did you solve it?


egoppel Wed, 07/18/2007 - 05:11

also looking in the forum:

this topic is exactly the same as i am experiencing:

IP Telephony: CCM unable to call into CME (VOIP)

however no resolution is provided.

m-haddad Fri, 09/28/2007 - 17:40

I am having same issue and the codecs are correct from both ends.

Any help is really appreciated,


CapitaServicedesk Mon, 10/01/2007 - 07:00

I hope you have included

dtmf-relay h245-alphanumeric on your dial-peers pointing towards the respective callmanagers on the GW

m-haddad Mon, 10/01/2007 - 11:31

Yes I have this included. THe problem is that the phone behind the CCM is ringing. Once the user picks up the phone he hears two beeps and then the calls drops. I have did some debuging on the VG and the reason code for dropping the call is 38 which means network dissorder.

I am doing more troubleshooting and appreciate any help,


egoppel Mon, 10/01/2007 - 13:14


so far i have seen, the problem lies in the fact that i need an ip ip gw to solve this issue.

i tried to achieve this in my lab, and it did solve the issue.

the cause of this problem was the h245 negotiation and capabilities exchange between a CME and CCM, i need to look up the details again, but i do have an explanation for it.

but first i`m going on leave for 2 weeks now, so as soon as i am back, i will try to follow up on the details.

good luck,


labtel Fri, 11/16/2007 - 08:53


What was the cause of the problem ?



m-haddad Mon, 11/19/2007 - 16:12


Sorry for the delayed reply, the customer from the other end was using an E1 E&M signaling with the PBX. We ended up changing the E1 card to ISDN E1 and the calls went through. As you can see it is an E&M signaling issue but this was the fastest fix to the problem.

Hope this helps,



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