Hi,
Could not find this answer, so would appreciate any hints.

I have registered 2 sip phones using the same extension number.

When I dial this extension number, only one sip phone rings.

However I need both of them to start ringing.

Is it possible, that when I dial the number - both other phones will ring, not only one..? 
And when I answer on a phone, another one would stop ringing.


Thank you,
Vitalie