Connecting handset via Direct SIP

[jmp28]

I have an on prem 3CX system that I would like to connect a handset to it from outside the network (via direct SIP). I have manually added the phone to an ext but it wont connect. Its a Grandstream GRP2615 and I can't figure out why. Not sure if its the handset, 3CX or the firewall the 3CX server sits behind. Greatly appreciate some guidance on how to troubleshoot.

 

[TheodorosG_3CX]

STUN provisioning is not a supported method.
I would suggest to use an SBC on the remote location and also ensure that the phone is on the latest supported firmware version.

 

[jmp28]

Thanks. I am still learning my way around everything in 3CX, is it possible to get a link with instructions to install an SBC. If we install an SBC, would that have an affect on all the handsets that are already in the network. Also, 3CX is sitting behind a Sophos firewall, would any ports need to opened to allow the external handset to communicate with 3CX.
Thanks again.

 

[TheodorosG_3CX]

For the on-premise SBC installation you can refer to the guideline here.
Keep in mind though that a router phone is also a solution which is actually an SBC running on the phone. Check below links for more information:
• https://www.3cx.com/blog/docs/sbc-router-phone/
• https://www.3cx.com/sip-phones/

Of course since you move to SBC all phones will require to factory reset and reprovision.
Note that the SBC will allow you to overcome any firewall configurations that are required with STUN. For the network you need to ensure that you are able to reach the PBX over https for the provisioning and tunnel connection over 5090 is also also allowed. Check the guideline here for more information.

 

[jmp28]

Thanks, appreciate your help with this.

 

[TheodorosG_3CX]

You are welcome