Issue with GSM codec on the T46G

[Wilson_Yealink]

Hi Errol,

I am sorry to tell you Yealink T46 phone would not support the GSM codec any more in the V73 version.
For your doubt, during the SDP negotiation, the initiator give some types of support codec , and in which the recipient to choose their own kind, and then complete the interaction. Followed by the establishment of the RTP stream. So if you set the other sides don't have same codec in the codec list and your pbx server does not support the transfer function of the codec, they can't establish call with each other.

So please enabled the same codec on other sides then try again.
For example, Calling between the Yealink T46G (with G722, PCMU,PCMA enabled) and Zoiper / CSIPSimple (G722, PCMU,PCMA enabled) to confirm whether there is audio issue?

BTW, may I know why do you need to test the GSM codec with Yealink phone?
thanks