VOIP / SIP-Trunk / Aastra 5000 axs
We encounter following problem.
Sometimes the calls come true, most of the time they don't. We can call outward every time.
The setup is as follow.
Internet --> orange (modem/router) in DMZ --> Firebox T15 --> PBX
Policies: port forwarding to the PBX (ports forwarded: TCP/UDP 5060, TCP/UDP 40000-40999, TCP/UDP 16384-32767).
FROM: any-External to IP PBX
NO - SIP_alg.
Thanks in advance,