Moving from STUN to SBC on 3CX V18

[Scot Busby]

I have an on-premise v18 (Build 31) PBX in which I have a couple of remote phones (Fanvil X5S and X6U with the latest supported firmware) connected using STUN. These have been working without issue for quite some time, but we are getting ready to add a new division which will be completely remove and I want to move to SBC. I have setup a small virtual server which is running v20.0.100 of the SBC. The new server is on the same local network as the phone system and is fully provisioned in the 3CX phone system.

When I change the provisioning of the phones from STUN to SBC and reboot the phones, When the phone comes back up, I receive a event in 3CX that the provisioning file for the MAC address of the phone was successfully generated, however, the phone lines do not register and calls are not able to be placed or received.

When I switch the provisioning back to STUN, the phones work fine.

I saw a post where someone suggested resetting the phone to factory and re-adding it using the SBC provisioning from the start. I tried that, but received the same result.

From my understanding - if STUN works, SBC should work, but I reviewed the router settings and the server ports, just to make sure and all seemed configured ok.

Any suggestions from anyone?

Thank you!

 

[SteveITS]

The new server is on the same local network as the phone system

The SBC needs to be on the same network as the phone.

 

[Scot Busby]

The SBC needs to be on the same network as the phone.

The phone system, in-office phones and SBC are on the same local in-office network.

 

[SteveITS]

The phone system, in-office phones and SBC are on the same local in-office network.

In that case neither STUN nor an SBC would be necessary...you mentioned "remote" phones, however? A phone not on the same network as the 3CX server needs to connect through an SBC or router phone on its same network, which tunnels out to the 3CX server.

 

[Scot Busby]

In that case neither STUN nor an SBC would be necessary...you mentioned "remote" phones, however? A phone not on the same network as the 3CX server needs to connect through an SBC or router phone on its same network, which tunnels out to the 3CX server.

Yes, correct. I have an office with phones and a few (right now) phones which are in remote, work-from-home based situations. Those are using STUN today and connect without issue, however, with the increase in remote phones we are going to have and better security/reliability with the SBC, I wanted to migrate those phones to the SBC and work out any issues before we have to add the other remote phones.
As I mentioned, STUN works without issue, but SBC does not, for some reason. The SBC also is green and shows up in the phone system, so this seems to be configured correctly, so I am running out of ideas.

 

[ivank]

Your SBCs should be located at those homes then, you misunderstand the whole concept I'm afraid

 

[SteveITS]

The other option is a router phone at each home, though that's the V2 Fanvil X models. Otherwise the SBC software can be run on a PC at home.

 

[JohnS_3CX]

The SBC needs to be at the remote site, absolutely not at the phone system site.

Also, you cannot simply switch them from STUN to SBC, they need to be factory reset and reprovisioned, at the remote site where the SBC lies. The current test as you carried it out is not considered a valid setup.

 

[Scot Busby]

Thank you all for the input. I have been able to get it working using the above comments. Most of the work-at-home staff do not have the ability to have an "always on" device which can run the SBC, so it may have to be installed on their laptops. Understanding, in this situation, the phone won't be able to connect unless their laptop is on. I could also deploy a fleet of Pi's, but thinking about all that, it seems STUN is a much easier option.

 

[SteveITS]

They could also use a headset on their laptop, and the web client or PWA or Store app. Or 3CX mobile app.

If you were going to buy Pis, probably better to get a router phone model and then the phone is portable by itself.

 

[Davdi]

We have moved to router phones and found them to be particularly easy and reliable. If you are on v18 the router phone has to be setup in the admin portion of the webclient (accessed by system owner extension). Also in v18, a router phone needs to be the first phone on an extension. This means that during testing you should add the router phone to an extension with no phone configured. Then when deploying, if an extension has existing phones, you will need to delete the existing phones from the extension, create and add the router phone and then re-add any stun phones back into the extension (if you still need them).

 

[Scot Busby]

Thanks everyone. After talking with the team, I think I have developed a solution which will work for all with this while also leveraging SBC through router phones. Since the team is dispersed, router phones make the most sense.

 

[NicholasP_3CX]

For anyone else reading this thread in the future, to keep it simple...

The SBC's main task is to establish a secure connection between a network where the phones are, and the PBX which is in a separate location altogether.

This could be through a dedicated SBC device or a router phone.