Assistance Needed – Connecting UniFi G3 Intercom to 3CX PBX

[Neil Willis]

Hello,


We have purchased a UniFi G3 intercom for our building and are attempting to connect it to the 3CX PBX system, but so far, we’ve been unsuccessful.


We have configured the SIP settings and created a dedicated SIP account for the intercom; however, the device does not call any of the extensions set up in 3CX. We have thoroughly checked the username, extension number, and password for the account, but the issue persists.


Additionally, we have explored setting it up as an IP phone that is not listed in the 3CX system, but the option does not appear for us.


Does anyone know how to successfully connect the UniFi G3 intercom to the 3CX system?


For reference, we have verified that the device is assigned to the correct VLAN and IP address, so it should be able to access the 3CX system.


Thank you.

 

[fortech]

Hi, have you reviewed other discussions about setup of generic devices / SIP Client against 3cx? Assuming the Unifi intercom device does pretty-standard-SIP (most likely) then - in theory - a normal setup process for a 'generic unsupported' device should be a viable method. I checked and there are some threads that might be helpful,

Post in thread 'is it possible to setup 3cx on Linksys PAP2'

Apr 19, 2025

hi, so I am really not sure. Possibly you may wish to do a reset on the device, I would recommend you do some google search and see if anything looks relevant for your particular part. For example maybe? this process will be relevant (? > https://wiki.voip.ms/article/Cisco_Linksys_PAP2T#Linksys_PAP2T_ATA_Adapter_Reset_Procedure )

if you can get a reset done, you might want to see if there is a 'newer' firmware than what you had on the device
or maybe not

alternately, you may wish to try hitting the webadmin page of the device from a different browser / incognito session in case...

• fortech

note you may need to tweak setting in your 3cx to permit a non-tunneled / non-3cx client agent to make direct SIP connection to your 3cx server. OR you might use an intermediate 3cx SBC in the same LAN as your Unifi Intercom device, and direct the SIP Intercom to talk to your SBC-SIP-Proxy and not directly to the 3cx instance itself.

This is ~definitely (In theory) possible - I have various generic sip devices talking to 3cx OK at various sites
and while they are a tiny bit fiddley to setup... they generally work fine once you finesse it suitably.
(ie, Handytone ATA, Sipura ATA, non-supported polycom sip speakerphone, slightly older SIP voip handset, etc etc).

Otherwise / if possible you may need to see about digging into logs on both the 3cx side, as well as on the client-device side, to see if there are any hints about what is your problem point.

Good luck.

Tim

 

[Neil Willis]

Hello,

I reviewed the link you sent along with the settings suggestions for the SIP account and the Ubiquiti intercom. It appears that there are no logs on either end, as 3CX isn’t receiving any calls from the device. This could mean that something is blocking the signal in between, or that 3CX is rejecting the device’s login each time it attempts to call. Please note that both devices are on the same VLAN and that the non-3CX agent function is enabled.

Thank you,
Neil

 

[AWS2P]

Do you have an SBC on phones location?

 

[Neil Willis]

Hello, no and for some reason will not let me

Do you have an SBC on phones location?

No, unfortunately, it won't allow me to install it on another PC for some reason. However, I’ve found a workaround for now. I’ve configured the intercom system to call in as usual, and 3CX applies a CIC rule to route it through a call group. This seems to be the simplest way to get it working, which I’ve successfully implemented. Since we’re transitioning to Teams in the future anyway, this solution should suffice for now.


I appreciate your help—thank you!