Calls randomly dropping upon transfer to queue

[jthackery]

We have an enterprise 3CX installation and have calls that will randomly drop. The call comes in and get an announcement to select an option in the digital receptionist and that sends the calls to the specified queue. Once selected the caller is sent there and the hold music may play for a second or so and then the call gets dropped. It doesn't ring to an agent or stay on hold for more than a second after the transfer and the call will appear as lost call in the queue. It doesn't seem to matter which queue is selected...I literally just watched a call come in and drop in one queue and then call back and get dropped in the second queue. Anyone experience this? Is there some setting that I am overlooking in the queue that could cause this (fyi the example I just gave literally came in when multiple agents were available and no other calls were in queue or on the phone with anyone). As I am finishing this another call has come in and been answered as it should have been. Thanks for any help.

 

[jthackery]

I had our local support setup Wireshark to track the issue and he says that our carrier (Bandwidth) is sending a BYE message which is causing the call to disconnect. Reached out to our carrier to provide SIP call control traces and they said that they were not available, but they said it was 3CX that sent the BYE to disconnect the call. Any ideas to help get around this finger pointing between the two and get this resolved? Thanks.

 

[TheodorosG_3CX]

Since the call is being rejected from the provider they will need to clarify why, however under the Sip Trunk option are the Re-invites and Replaces enabled?

 

[jthackery]

No those were not enabled. I have now enabled and will keep monitoring to see if that resolves the issue. Thank you.

 

[TheodorosG_3CX]

Those options should be disabled.
You need to check further with your provider.

 

[jthackery]

I had enabled them yesterday but have disabled again. Neither option seems to make a difference. Bandwidth sent me a capture of a couple of calls from yesterday and it shows that a BYE was initiated by 3CX for some reason. I've asked them to help review our setup because their website configuration page for 3CX is not working.