External caller has no audio when we make outbound calls

[belfairsacademy]

Hi All

Complete rookie with this level of VOIP work but hope you might be able to break it down for what I need to be looking at.

All of a sudden we are having one way audio when we make external calls, we can here the external caller but they cannot hear us.

Incoming calls are fine and internal calls are also fine. Nothing has been changed on the system, other than a holiday schedule going live. I have tried removing this just to see if there was something underlying to cause this but has no luck.

We are running quite an old system, Cisco 7828 with a VG2921 gateway. CUCM version 8.5, ISDN30, have had the telco in and all lines report no issue. Never had any issues the system and support was left to expire before my appointment and then we struggled to be able to get any third party to support due to the age.

Any help on where to start looking would be amazing

[Rajan]

If possible you can get a packet capture from Phone used to make a call to have a look at the RTP streams.

HTH

Rajan

Pls rate all useful posts

[belfairsacademy]

Hi Rajan

Thanks for your reply, best way to go about getting a packet capture on the phone?

[Rajan]

Procedure to take capture from phone:

https://community.cisco.com/t5/collaboration-voice-and-video/collecting-a-packet-capture-from-a-cisco-ip-phone/ta-p/3119480

HTH

Rajan

[Rajan]

Procedure to take capture from phone:

https://community.cisco.com/t5/collaboration-voice-and-video/collecting-a-packet-capture-from-a-cisco-ip-phone/ta-p/3119480

HTH
Rajan

[Carlo Poggiarelli]

Hi Rajan,

Which protocol are you using between CUCM and VG?

Please let me know

Regards

Carlo

[belfairsacademy]

Hi Carlo

what do you mean by which protocol?

[Rajan]

Specific protocol will be used for communication between CUCM and Voice Gateway. You could check on CUCM whether the gateway is configured with MGCP or SIP.

[belfairsacademy]

Hi Rajan

The send and receive packets from the phone are reporting as 1800 each when i place a call and look at the stream stats on the actual phone. 

Does this provide any useful info?