How to troubleshoot mobile communication on VoIP Gateway Yeastar?

Question

VoIP

Good afternoon!

I have a problem with communication in the operator's network. The essence of the problem is that when making a call, the client cannot hear the Call Center operator. Moreover, 3CX, which we use for IP telephony, perfectly hears both sides (the conclusion is based on listening to the recording of conversations). The problem repeats every 2-3 calls, you have to call back. The topology is as follows: 3CX --> NGFW Firewall --> Yeastar TG400 Mobile Gateway. The firewall does not block anything. The problem manifests itself differently for each user. For some, every 10 calls, for others, every 2 calls. The communication operator admits that the network is weak and decided to install a signal amplifier. The signal level on the router varies within 2-3 scales out of four.

The question is, how can you troubleshoot this problem? Removing dumps from interfaces and subsequent analysis in Wireshark did not lead to anything. Yes, and the recording of conversations and logs on the firewall exclude problems in the local network.

Answer 1

How did this removal of the dump not help? Did you find problem calls in Wireshark? Can you listen to it using Wireshark itself? Is the hearing two way?