SBC not working?

[ZacSC]

Hello,

I am trying to get an SBC working and running into some issues, not exactly sure what the problem is. I have a 3CX phone system set up at another site, it works great, testing on migrating that to a place where it supports several sites with SBCs.

So I have the SBC software setup on a Raspberry Pi 3b+, connected to a network with Unifi equipment (USG and Unifi Switch) and then a Yealink phone also plugged into that same switch. The SBC shows its connected / up (although UDP is down?) and the phone never shows up for me to adopt. I have tried plugging things into different ports, rebooting everything, reading through the SBC setup etc. This 3CX phone is presently running on MS Azure and was created with the PBX Express. Any thoughts on what I am missing?

Here is the stats page for the SBC:

Statistics

Status	UP
Uptime	0 min
Build Version	16.0.390
Agents Behind SBC	0
Calls Behind SBC	0
TCP Encrypted	No
TCP Packets Received/Sent	2/1
UDP Status	DOWN
UDP Encrypted	No
UDP Packets Received/Sent	0/0
UDP Ping	- ms
Operating System	Raspbian
System CPU Usage	%
System Memory Usage	%
SBC Memory Usage	%
Disk Usage	%
Bandwidth Used From PBX (Rx)	-
Bandwidth Used To PBX (Tx)	-
RTP Packets Received/Lost from SBC	/ (0 %)
RTP Packets Received/Lost from PBX	/ (0 %)

 

[JohnS_3CX]

Check the Pi's own uptime to ensure it doesn't reboot. Before troubleshooting why the phone does not show up, its important that the SBC stays stable.

If the TLS connection keeps dropping then something is "breaking" the TLS connection on your firewall perhaps since the handshake fails. Or possibly its just a bad physical connection (anywhere in the chain)? UDP will be more tolerant, but you lose TLS effectively. On a good connection TLS is very stable.

Once all is set and done, resetting the phone should make it appear as a new phone. If not, then at that point you will need to look at multicast, since this is how the phone reports its presence to the SBC (and then to the PBX).