No audio on Sip Trunk

[Tinos]

Hi all.
I have a Sip Trunk on MIVB9.1 which has no audio both ways. Which setting should I look at to troubleshoot audio on MIVB?
Important:If I replace the MIVB with MIVO400 the Sip Trunk has audio which kind of excludes network and service provider. I am sure the no audio is a setting out of place in MIVB. Please assist with what I may check.

Thank you.

 

[Valamagules]

Is there an MBG SIP proxy in the picture or is it direct SIP trunk to the MiVB?

If direct SIP, then check handset network connection back to the SIP provider as RTP will flow directly from handset to SIP carrier.
Signalling will be directed through the MiVB however RTP flows from handset to provider unless it's anchored by an MBG proxy.

Clever men learns what Wise men shares!

 

[Tinos]

My challenge is on the fortigate firewall and the support company is struggling with NAT policies for MIVB and public IP for incoming and outgoing. Does anyone have a tested fortigate configuration for a similar setup? Sip trunk connecting to carrier with public IP and no MBG.

 

[AlphaMann]

I have done Fortigate's many times, however always with MBG. I have played around with SIP trunks without ones and it is always a nightmare.
Spend the couple of bucks and save many hours. Cost to the customer would be a wash at worst.

 

[Tinos]

Is there someone who can describe the configuration required on Fortigate side in the absence of MBG?