External calls to Grandstream HT814 one way audio

[NexusIT]

We are having an issue after upgrading from V18 U5 to V18 U7 (441) with one way audio on our grandstream ATAs only on external calls. We can have an external call come into our yealink phones with audio working fine. The second they transfer the call to the ATA, the party on the ATA can't hear the external caller. If an external call comes in directly to the ATA, same thing. We've checked ports and that is fine. Our SIP provider also mentions they aren't seeing any issues. We've upgraded the firmware on our ATAs (Both current and beta firmwares) and no change. Packet traces between the ATA and the phone system don't show any errors either.

 

[OlegR_3CX]

Sounds like a networking issue between the 3CX System and the gateway. The only way this can be analyzed is to run the networking capture and see the SIP with the SDP negotiation as well as the RTP traffic between the two. If you will see that the 3CX System sends the audio to the IP of the FXS, then you could get in touch with Grandstream support to advise further.

 

[JOSUA]

I am having the same problem

 

[leejor]

Have you checked that the Codecs on the ATAs include those used by your provider?