Inbounding calling dropping

[tmoreau]

So my 3cx sbc ran fine for almost a month and out of the blue I got this dreaded inbound 32 second bug. I've already tried all the tools available, tried different routers with different settings in each.

So i'm wondering could it be this issue with the calls?

03/25/2021 8:53:01 PM - Leg L:17.3[Extn:201] is terminated: Cause: BYE from local

03/25/2021 8:52:36 PM - [CM503007]: Call(C:17): Extn:201 has joined, contact <sip:[email protected]:5060/UDP>

03/25/2021 8:52:36 PM - L:17.3[Extn:201] has joined to L:17.1[Line:10001<<+1807*******]

03/25/2021 8:52:34 PM - [CM505001]: Endpoint Extn:201: Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [Grandstream GXP2170 1.0.11.16 000b82fbd1d8] PBX contact: [sip:[email protected]:5060]

 

[StefanW]

Do you use a hosted instance from 3cx or do you manage it yourself?

does it occur between exten calls or only when dialling out? What is your sip trunk provider in that case?

 

[tmoreau]

Ours is hosted on the cloud on 3cx, our VOIP provider is Flowroute. I've tried two different routers over there at that one location, I fired up my test sbc at home and took some phones and setup a number from that provider here and it works fine for inbound and outbound.

I used a plain jane Linksys router at the problematic location, other than a UDM PRO from Ubiquiti, the UDM PRO worked fine until yesterday when the calls started dropping so i'm suspecting its either the PTP Link to this location or the switch its connected to on the other side. I'm going to be calling Flowroute to see what they see on there side this morning.

If I have 3 other locations with SBC's doing fine them im getting closed to figuring it out.

And yes i've brought other SBC's over there and tested on both Routers. and used one of the routers fine in another location.

 

[NickD_3CX]

I sounds like you have ruled out quite a few things. I'll admit, my first thought was maybe something either with Flowroute or the SIP Trunk settings. but as you have tried with phones behind an SBC from a different location to the same 3CX, then that should rule it out.

What you could do is that, from the problematic location, from one of the phones call *777, which is the Echo Extension, and keep the call up for 1 minute while speaking into the mic to make sure there is 2-way audio.
If the call drop after 32 seconds, then despite the above, it could be something with Flowroute.

If this does happen, before calling Flowroute, go into the SIP Trunk settings in the "Options" tab and make sure that you are not somehow overriding the IP in the 'Contact' header. The setting should be like this: