Unsupported Grandstream HT813 and apartment buzzer

[ProudCanadian]

I am desperately hoping someone can help me with this...

I have an HT813 that I am trying to use the FXO port on. The building I am in uses the wall jacks for the front lobby buzzer and seems to just ring through like a normal phone line, but there is no dial tone if there isn't an active call.

All I am trying to do is get the HT813 to bring the calls into 3CX so I can buzz people in remotely, and for the life of me cannot figure it out. Any help would be VERY appreciated!

(I made sure to be using port 5062, FXS is disabled on the device, firmware is latest, I am aware it is unsupported, I am using just the WAN port with LAN disabled)

 

[leejor]

Did you come across this...

https://www.3cx.com/community/threads/grandstream-ht813-fxo-issues.62062/

What is the 3CX Activity Log showing (Verbose), if anything, when the 813 attempts to forward a call to 3CX? If you don't see any sign of a call attempt, then the settings in the 813 are not correct. Compare to the settings in the link.

One problem you might encounter is because of the lack of battery, on the line, if there is no phone line to a PSTN central office. The 813 may assume that the phone line is in use, so you may, or may not, have to "adjust" any line in-use voltage settings. When there is an incoming call from your buildings Enterphone system there will be battery and ring generator.

There are also a number of other posts, on the forum, about that device, if you do a search.

I assume that you are hosting 3CX locally.

 

[cobaltit]

You also probably want to look in other forums, like Grandstream or Asterisk. The only 3CX part is getting the ATA to talk to 3CX but the issue getting the intercom to talk to the ATA as far as off-hook status, line voltage, etc like @leejor mentioned is not 3CX specific.