No incoming sound from Yealink w60p devices?

Question

SIP

Hello!
Please help with solving the problem,

The network has asterisk (freepbx) and a branch network, as in the diagram. Asterisk 2 network cards, one for the internal network and the other for connecting to the provider. Recently purchased new Yealink devices. When you call outside (mobile operators) from data from these devices, you can hear, but you don’t hear. There are no such problems on Grandtream devices.

Answer 1

It looks like the phone and the server were communicating in different codecs. It is necessary to show the same set of codecs with the same sequence. The codec 711a (alaw) should be in priority.