Issue with inbound IVR/Voicemail audio with SIP provider

[NZRob99]

Hi all,

We have an interesting issue with our SIP trunks. When we have 3CX set up to go directly through to a phone then we get 2 way audio and everything is OK. The issue we have is when the destination is to an IVR or a voicemail on the PBX then we do not have any audio. Changing the SIP provider and everything works OK.

any ideas?

Thank
Rob

 

[cobaltit]

Does you system pass the firewall test?

 

[NZRob99]

yes system passes firewall test, we have played around with PBX delivers audio and still having issues.

 

[cobaltit]

I'm assuming you aren't using a tested SIP trunking provider. So given that, I'd play with the 'Supports Re-invites' and 'Supports Replaces' options on the trunk