Fongo SIP and door phone

[damdam]

Hello,

I just moved to a new condo in town and plugged my HT701 with Fongo on the wall and everything just works fine. But I have a problem with the door phone. People visiting us have to dial a 3 number code to make our phone ring and then we have to press a number on our phone to open the door.

What happen: My phone doesen't ring. The visitor hears a dial tone (just like he hang up my phone line). Nevertheless, if I hang up my phone, I can hear the dial tone and my visitor. I can also open the door by pressing the good key.

Question: How can the HT701 "understand" that someone is calling from the door phone and stop the dial tone and make my telephone rings?

I hope my explainations are clear!

Thanks a lot !

Damien