Third-party phone call are mute

[fernandodonadio]

Hello, guys,

I have a third-party ip phone in a branch office registered on CUCM 11.5.

When I call to any internal extension, it works fine. But when I try to call to any number going through the PSTN, the call gets completed, but muted.

I'm using a ISR4331 H323 gateway and I tried to debug this mute calls, but I do not see anything wrong.

Just as additional information, I have Cisco IP phones in this office registered on the same CUCM using the same Voice Gateway and they are working properly. 

Can someone give me any direction, please?

Regards,

Fernando

[Brandon Buffin]

Sounds like a routing problem. Does the 3rd party phone have an IP address in the same subnet as the Cisco phones?

Brandon

[fernandodonadio]

Hi Brandon,

Yes, both are in the same vlan.

[Rolando Valenzuela]

Just to make sure, is this accurate?

Cisco Phone -> CUCM -> Gateway -> PSTN ---- This WORKS

Third-party Phone -> CUCM-> Cisco Phone ---- This also WORKS

Third-party Phone -> CUCM -> Gateway -> PSTN ---- This does NOT work.

If it is, the problem is either between CUCM -> Gateway or Gateway -> PSTN, please check

• Supported codecs.
• Is the call being transcoded?
  
• Media Flow Through vs. Media Flow Around.