One Way Audio with SBC (Session Border Controller)

[David Schumann]

Hello,
I am experiencing One Way Audio with calls going through a SBC. Initially I had no ports forwarded to the SBC. I have since tried forwarding 5090 without success.
The One Way Audio happens when the Phone connected to the SBC dials a number. If I call the Phone connected to the SBC the Audio seems to work in both directions.
I will conduct more detailed tests this afternoon and post my findings.

Thanks in advance for any help.
Kind regards,
DS

 

[Saqqara]

You do not have to do any portforwarding to the SBC,

 

[Lee Cramman]

Is this a new install or a new problem in an existing install?

As @Saqqara said, you should require no port forwarding for an SBC.

Can you verify that phone is definitely provisioned to connect via the SBC and that this was done by PNP? It's easy to start out testing without an SBC and not realise that the phones haven't picked up the new settings after the SBC is added.

Also, is the SBC definitely on the same network as the phones with no clever routing or NAT in between?

I know this is pretty fundamental stuff but, due to the nature of how the connection works, usualy an SBC either works properly or it doesn't work at all so your problem is a little unusual.