bradyd3 :
Network Map
\Motorola SBG6580-G228> ETHERNET> Airvana Hub Bub C1-600-RT >ETHERNET> My PC
Are you able to connect the PC directly to the Motorola?
Having the Airvana between your PC and the Motorola will needlessly complicate configuration, and port forwarding will not work unless ports are forwarded in the Airvana as well.
I'm assuming the Airvana is being used as a cellular signal booster, so there shouldn't be any need to have your PC connected to it.
If you can connect it directly to the Motorola, you'll need to adjust the port forward IP address, and that should allow your application to work.