Connect clients disconnects after 31 seconds

VitalPBX
1

Situation
connect client disconnects after 31 sec outbound calls only.
inbound are ok
on wifi it is ok
so only on mobile carrier network
device on carrier ip is behind CGNAT (assumed)
rtp timeouts are not the issue as these have been adjusted to reflect potential issues for timeouts
all other timeouts for connection SIP properties adjusted to see if it helps.
Diagnosis
This seems to be a re-invite issue, Asterisk sends re-invite to new connection using CGNAT address and it never receives a reply as the re-invite never makes it. It times out and disconnects 31 secs.
Has anyone else using the connect client

  1. Seen this
  2. Come up with a solution.
2

Check your NAT settings in PJSIP Settings inside the PBX.
Could also be a firewall issue if you have one in front of your pbx

3

Also, please check that RTP Timeout is set to 0 in the PJSIP device profile settings.