Solved Windows client and CLI Phone Control using SBC

[John Kostakis]

Hi,

Im having an issue with using the CLI Mode in the 3CX Windows Client.

We are using Yealink T42G handsets and our 3CX Server is running on a Debian Virtual server in the cloud as we have 2 sites connected to it. Each site is running a local SBC Controller using Debian.

The issue is the Windows client is registered and detects the CLI Mode on the phone however when trying to dial from it the phone does not do anything. The only was i have managed to get it to work is when the phones are registered using Direct SIP mode instead of through the proxy.

From what i can tell the phone registers via the SBC perfectly fine however the Windows client always registers using the WAN Address even though i have forced it to register via the SBC controller.

The phone, PC and SBC controller are all on the same IP network\Range.

Does anyone know why the CLI mode wont work in this mode?


Thanks
John

 

[YiannisH_3CX]

Hello @John Kostakis

I would recommend using the web client introduced in V15.5 for CTI as it helps overcome network issues.
Just make sure you are running the supported firmware and the updated templates for V15.5
https://www.3cx.com/blog/releases/web-based-voip-client/
https://www.3cx.com/user-manual/web-client/

 

[John Kostakis]

Hi Yiannis,

The Web client does work fine, however i would like to use the Windows Client instead, would there be a reason why it would not be working?


Thanks
John

 

[YiannisH_3CX]

The CTI function depends on the network configuration. For CTI to work behind the SBC you need the phone connected through the SBC and the 3cx client set to CTI. In this scenario the PBX will let the client know the local IP of the phone. When you try to make a call the client will send the request directly to the phone. So if the messages are not reaching the phone then something is blocking it in the network.
So the client and the IP phone at the remote site need to be in the same lan so they can directly communicate.

 

[John Kostakis]

Hi @YiannisH_3CX ,

Just to confirm this is my current setup

3CX PBX in cloud Connected to SBC Controller on our LAN

SBC Controller is set to 192.168.1.6
IP Phone is set to 192.168.1.189
PC is set to 192.168.1.190

Everything is setup on the same network and all firewalls and restrictions have been turned off.

3CX Windows App is in CLI Mode. Is there a way to check if the Client is communicating with the phone?

 

[YiannisH_3CX]

The best way is running a wireshark capture on the client machine as well as on the phone. You should see the request (http) leaving the 3CX client machine. then you should check if the request reached the phone.

 

[John Kostakis]

Issue turned out to be the Custom tempate being used, created a new template with updated parameters and issue seems to be resolved.

 

[YiannisH_3CX]

Glad to hear the issue is resolved and thank you for sharing your solution