nortel softphone to access BCM behind NATing FW

I'm trying to configure my Juniper 5 GT firewall to allow some of our
employees in the feild to use the i2050 softphone on thier laptop

I have setup rules on my firewall to allow ports 7000, 28000-28255,
51000-51200 to point to the BCM's internal interface

The SW connects, we can dial out, and they can hear the caller, but
the caller can hear the softphone users

I'm thought maybe i'm missing a port, so i opened everything for a
test, same results.

i tried the laptop on the lan (reconfig to point to the internal
[private] IP) and it works fine

is NAT causing me problems?

anybody have any ideas?


Paul