[AFMUG] Sip Behind NAT

[Nate Burke via Af]

I know the short answer is 'Don't' but let's pretend for a minute I 
don't have an option.  (Mikrotik router, Grandstream 6102 PBX)

I have a trunk setup to the carrier, and I am doing a DST-NAT rule for 
all traffic from the carrier's IP Address to the Internal IP of the 
Grandstream.  I am also dst-nat all UDP ports 8766-35000 traffic to the 
grandstream.  After a few minutes an incoming call will have 1 way 
audio, but then the next call right after that will be fine.    I do 
have the NAT settings set in the grandstream.

It seems like I'm just missing something simple to keep it working all 
the time.  Any pointers?

Nate