Cisco phone One way Audio

[payamkhosravi]

Dears

Recently I encountered a problem in case of one way audio between two IP-Phones

In my case I installed cucm cluster(one Publisher and one Subscriber) ver 11.5.1

Our phones are 7841 with firmware ver 11.5 , all of switches are cisco 2960-X series with 1G ports and i create some data vlan for pc and some voice vlan for ip-phones and simply one Cisco 3850 switches do inter vlan routing between vlans

Routing is completely fine because computers and ip-phones in different vlans connect to each others without problem . 

Sometimes and fully randomly users report that when dial other ip-phone(one ip-phone call ather ip-phone) they can't hear other side and in sometimes both of sides can't hear each others but when disconnect and dial again everything is ok , some days it happens more but some days never happens

I had this problem in other project with 3905 phones but that problem was solved by enabling MTP in each phone and configuring media resource group list in CUCM (Software MTP) but in this case it didn't work

Please let me know how can solve the problem???

Thanks

[BradEast1]

In my experience, one-way audio or no audio is almost always an issue with the underlying network. You can begin troubleshooting by monitoring the "Sender Packets" and "Rcvr Packets" of the phone GUI while experiencing the issue. Make sure Web Access is enabled on the device, Click the IPv4 Address URL from CUCM and it will launch the GUI of the device. From there you can go to "Streaming Statistics" and "Stream 1".

[payamkhosravi]

There is not any suspicious thing in my network , in your opinion what part of network I have to check ???

One important point that I figure it out recently is when I restart cucm everything will be ok for almost one week and after that problem start (I'm not sure restarting completely related to problem but for two times that i restart, the problem was solved temporary) !!!!!!!!!!!!!!!!!!

I'm realy confused about this issue !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[saif musa]

Hi,

Did you set a gateway IP address for your CUCM? also, in which VLAN did you connect your CUCM?

[HARIS_HUSSAIN]

Are you Phone in same Subnet or Different Subnet. If in Different subnet is there any firewall in between?

[Slavik Bialik]

I would try to simulate the issue and capture via Wireshark the SIP & RTP traffic. You'll definitely see the issue there.

[zahi.nghaiwi]

Hi;

did you solve this issue? 

We are experiencing the same problem

[saif musa]

Hi,

Do you are experiencing this issue between two different networks ? or within the same network ?