We've tested this issue with many routers now,
Most of the routers do not stuck,
but they also do not allow a video call to actually happen,
the call it self is hanging (stucking) after 1 second.
if linphone is aiming to be a commercial grade solution for companies wishing to deploy a sip software (under license),
then there should be a better solution then disabling the ALG feature in every router in the world...
I am sure that when the ALG was designed it was not designed for the purpose of disabling it worldwide.