One Way Audio with Hosted 3CX

[2evolve]

Hi All,
When we call using just Softphone, or even with physical phones configured at another premises we have no issues but we currently have no Inbound Audio to a premises. I can hear them fine, whether they call us or we call them. I've captured the call on the PBX and it has both audio streams.
Any thoughts please?

 

[ChrisC_3CX]

On the premises facing the inbound audio issues, have you used softphones as well? If yes, does the same issue occur?

 

[2evolve]

It's OK, I knew it was going to be a firewall issue, based upon one-way audio experience, but couldn't fathom the cause as no inbound ports needed to premises (PBX is Hosted) so have solved by DMZ gateway device to allow all traffic to next hop which is handling the firewall from here on.

 

[ChrisC_3CX]

In the event your remote IP Phones are configured as STUN devices, then you actually will need port forwarding on the remote site (where the IP Phones reside) to ensure smooth operation. If you are in fact using the STUN provisioning method for the affected IP Phones,