On prem 3CX v18.
We have a persisstant issue with inbound calls which presents as 1 way audio. We do not use IVR / Digital receptionist so all calls are directed to a group, all members of group are local extensions running 3CX client. In simple terms, caller rings, we answer and hear them but they can't hear us. 30 seconds later we've all hung up and they try again, usually with success. This probably effects 30% of inbound calls. Outbound calls are fine.
Majority of our inbound calls are from regular callers and it's obvious that some callers never have an issue and some are almost guranteed to fail first attempt. The callers with issues are a mix of mobile and landline users.
Pcap shows the same (interesting?) results for both failed and sucessful calls which has been confirmed with VoiceFlex SIP provider.
"PBX is sending early media without sending 183 first".
So flow from pbx goes something like this.. (Invite) - 100 Trying -> 180 ringing -> RTP-> 200 OK
It would seem that the above flow is accepted or handled by some inbound provers but not others.
Indeed call recording and captures show that audio is making it out of the PBX, just earlier than caller is expecting it.
I have toggled Earlier Media on and off, no difference and I've never seen a 183 in any pcap performed on inbound calls.
We have a persisstant issue with inbound calls which presents as 1 way audio. We do not use IVR / Digital receptionist so all calls are directed to a group, all members of group are local extensions running 3CX client. In simple terms, caller rings, we answer and hear them but they can't hear us. 30 seconds later we've all hung up and they try again, usually with success. This probably effects 30% of inbound calls. Outbound calls are fine.
Majority of our inbound calls are from regular callers and it's obvious that some callers never have an issue and some are almost guranteed to fail first attempt. The callers with issues are a mix of mobile and landline users.
Pcap shows the same (interesting?) results for both failed and sucessful calls which has been confirmed with VoiceFlex SIP provider.
"PBX is sending early media without sending 183 first".
So flow from pbx goes something like this.. (Invite) - 100 Trying -> 180 ringing -> RTP-> 200 OK
It would seem that the above flow is accepted or handled by some inbound provers but not others.
Indeed call recording and captures show that audio is making it out of the PBX, just earlier than caller is expecting it.
I have toggled Earlier Media on and off, no difference and I've never seen a 183 in any pcap performed on inbound calls.
