asterisk users - Feb 2009 - problem getting asterisk behind NAT to run with sipproxd

Hi people!
Asterisk PBX (version 1.6.5): I have Asterisk behind a NAT (192.168.1.2)
SIP Phone: A client behind NAT (192.168.1.3)
Softphone: One other client somewhere in the internet (also behind an NAT).

they want to speak with each other, and if they do, there is no sound.

if softphone in the internet is no more behind a NAT router, it can hear
SIP Phone but SIP Phone is not able to hear Softphone.

siproxd is installed on the same machine where the asterisk PBX is
installed, and I don't know how to configure it properly as well how the
sip.conf of the asterisk PBX should have to look like.


For any support I would thank you gladly.


Tamer