Problems with AVAYA IP phone connected via DI-604. The phone only works if the DMZ is configured on it. Port forwarding is not accepted

Question

Avaya

Actually a subject.

Why can this be so? the phone is stupid in every sense (only one phone can be connected to 1 external IP), model 1603 - works as it is written in the instructions on ports 1719 and 1720 - their forwarding does not help - NAPT error

Why can this be so? In the router, plugging and port forwarding does not work correctly, or does the phone with forwarding not work, only with DMZ? Or maybe some other port is being used that hasn't been reported? in that case, how do you know?

DMZ is not suitable due to the fact that a bunch of other services also try ports.

Answer 1

apparently wants RTP
Try forwarding 16384-32767/UDP
If it doesn't help, you'll have to forward 1024-65535/UDP.

Answer 2

Nothing is written in the dlink documentation about automatic pickup of RTP in h.323.
Such devices do not do full parsing of h.323. To guess the dynamic port number, heuristics are used - some rules that describe what offset in a particular packet is the port that needs to be forwarded additionally. Usually.
In practice, slightly more different parameters break the heuristic.
In your case, dlink obviously didn't guess right.
And in general, this is not a household device, but a component of AVAYA corporate telephony.
Contact your integrator or where you found it. He will solve all the problems for the appropriate money - he will sell the router that organizes the tunnel between the offices.

Answer 3

What protocol is the phone using? SIP or H.323?