incoming line not ringing softphone

hi
i have trixbox setup in my office and i have sip extensions at my house where i use a thompson router which has a voip port, and is configured as an extension.
i have an incoming line from voipuser which is configured to hit the ivr and one of the option is to ring my extension on the thompson router and that works fine.
now i have a softpone on my pc that and one of the option on the ivr is to ring the soft phone and this soft phone does not ring.
so is this correct because i do not have any port fowarding to any of my softphone and any incoming calls will go to the routers extension by default.
is there a way to make my softphone ring, i can ring any extensions and make outgoing calls from the soft extensions but not receive any calls.
just to summarise is it possible to have multiple sip extension in a house which is connected to an external trixbox and all the extension will be able to receive calls

thanks

I seem to remember that this has turned up before. The Thompson router has a voip connection to which the required ports (5060 UDP +other?) are probably "attached". You need incoming 5060 to be available to your IP phone and the softphone. It may be explained in the Thompson manual.

Check out this thread
http://www.voipuser.org/forum_topic_1608_0_asc_15.html