Good morning everyone. I'm encountering something i've never seen before. The scenerio is:
Phone A - internal phone
Phone B - internal phone
Phone C - external phone
Phone C calls Phone A, audio works.
Phone A now conferences Phone B. audio works between all 3 phones
If Phone A or Phone B drops off of the conference.....the internal phone cannot hear the external phone. The external phone CAN hear the internal phone
The same symptoms are seen if an internal phone initiates the call to an external number.
Any help would be great....thank you!
Did you resolve this issue? I am encountering the same issue and want to know what progress you made towards resolution.
The easiest way to find out what is happening is by capturing some SDI and SDL traces from CUCM and make sure that you include the calling/called numbers.
Let me know if you have them.
Worked with TAC on this and they had me do the following:
Create a new MRG that had the CUCM MTP and the Conf Bridge from the router and a new MRG that had transcoders. In the MRGL assigned to the phones, put the MTP/CONF MRG first and the transcoder MRG second. And this resolved the issue.
Hope this helps!
That is quite funny as one of our clients raised the same issue. In my case switching to software conference bridge did the trick. Of course this is going to be a temporary workaroung but it works.
...and seems like this is bug CSCtw53001 (at least by description: One-way audio when one party leaves the conference
I had the same problem at a customer.
The TAC engineer after a lot of research found that IOS version of the used router (ISR 2900) had a bug. (SR # 622906973)
She suggested us to both downgrade from 15.1.4M3 to 15.1.4M1 or upgrade to 15.2.2T
What CFB resources are you using? CUCM or Router? What router and IOS are you using?
Initially it was hardware CFB (so it might be related to IOS bug) and after I swapped to CUCM CFB - issue was resolved for my case.
I will check IOS version on Tuesday and will let you know.
Thank you for the hint anyway. Do you know bug ID?
Bug ID is CSCty23337.
Our problem description is under the Workaround section.
|H323 gateway /w CFB sends no RTP to IP phone when only 2 parties remain|
|Symptom: PRI----H323 gateway-----CUCM 8.x-----IP phone H323 gateway hosts a hardware CFB. During a conference call that involves IP phone and PSTN callers, if only two participants remain in the conference and one participant is PSTN caller, there's one way audio. IP phone cannot hear PSTN caller. Conditions: This behavior has been confirmed with 15.1.4M3 code with CUCM 8.6. This behavior doesn't happen when CUCM 7.1.5 is involved, or if 15.1.4M1 is used, or if the CFB is located on another router. Workaround: Upgrade to 15.2.2T or downgrade to 15.1.4M1, or use another router to host the CFB|
Good to hear that from you!
Please let us know when you update the router and if the issue gets resolved.
Note that if you want to continue with the M version, you need to downgrade to 15.1.4M1
I had the exact behavior after migrating phones from a 7.x CM environment to a 8.6.2 cluster. My gateway was running 15.1.(4)M4 code. I upgraded last night to 15.2.2T and the problem has been resolved.