Telstra Business SIP Not Registering

[garrick.cobcroft@gsconsul]

Hi, I have an OnPrem 3CX installation connecting to a Telstra Business SIP OneAccess One425. The Northbound side of the One425 registers fine, but every 2-3mins 3CX reports that it can't contact the NTU. The crazy part is, if I place an inbound call, the extensions ring normally and the trunk shows as registered. Approx 10mins after the call is complete, the trunk again shows unregistered and the logs repeatedly say that the NTU can't be contacted. Even when 3CX shows the trunk as registered, the NTU reports that it is unregistered. The main downside of this, is that outbound calls on this trunk don't work.

Cheers,
Garrick

 

[YiannisH_3CX]

Hello Garrick. Is the NTU and the PBX on the same network / vlan? Also are you using TCP for the connection? Looks like the TCP connection might be timing out.
You could run a pcap for a few minutes and see if there is a disconnection or reset of the connection. Also are you seeing an error for outbound calls? Is there anything logged on the event viewer of the system?

 

[garrick.cobcroft@gsconsul]

Hi Yiannish,

Thanks for following up on this. Firstly, the issue is no longer relevant as the number porting is now complete, so the customer is moved to a SIP trunk and cloud instance of 3CX. As it tuned out, we ended up parking the issue as we got notification of the number porting being scheduled for the next day.

But for completeness, in case anyone having the same issue comes across this thread:-
Yes - NTU and PABX on the same network and NTU in Gateway Attached mode.
I had run PCAP for about 10 mins prior to doing the forum post, and there was nothing showing in relation to the Testra registration. I could see the rejected outbound calls, which then failed over to the secondary trunk, but that's all. And no, nothing in the event logs relating to the outbound calls, as I say they simply fail to connect on the primary Telstra trunk, but then fail over and work on the secondary SIP trunk.

FWIW, Telstra doesn't sell or support Business SIP anymore, so I doubt that this is going to be an issue moving forward. This customer was very unique, in that he hadn't ever purchased an optional extra package known as business continuity. Without this package, it is impossible to do a trunk based call diversion. Thanks again for the follow up.