In our environment , we make an outbound call to external number whose phone is setting VoLTE .
When external user answered this call , then the prompt “number-not-answering” and this call was ended .
Our extensions was registed by pjsip .
The trunk with provider was working on chan_sip already .
This issue is specifc to VoLTE only .
We already use G.722 in audio codecs .
I can also see the error message in 487 header
Here is trunk’s outgoing peer details :
My provider told me maybe something wrong with maxptime parameter .
Our maxptime is 150 . Our provider told us this must be set as multiples of 20 of ptime.
Is there something wrong with this parameter ? Do you know how to fix this issue ?