Aastra 6755i no audio in or out

[ellenboa]

I have configured my Aastra 6755i IP phone to use my 3CX server. It is registering, i can establish a phone call, but no audio works. Not inbound nor outbound.

Thanks in advance for any help.

 

[mfm]

Hi,

Both audio streams not working might lead me to think its a stun issue. Also these phones are not supported I recommend you use on of the supported phones. Also you might try using the tunnel and see how you go.

 

[comresource]

Is this an external extension or on the local LAN? If local, make sure the firewall on the 3CX box is not blocking RTP packets.