Solved No Audio from ext to ext

[thames]

Hi Folks

This is an odd one and I'm trying to figure it out. I can dial from 101 to 102 and get audio just fine but, when I try and dial from 102 to 101 I get the ring tone and then no audio.

I bet this is gonna show me up as dumb! Anyone have a suggestion as to where to look?

All the best
Chris

 

[eddv123]

Hi Chris,

Where are the end-points located and what are they ? IP end-points, FXS extensions etc ? and where are they located ?

Have you traced with Wireshark per chance ?

 

[thames]

Hi Chris,
Where are the end-points located and what are they ? IP end-points, FXS extensions etc ? and where are they located ?

Hi Ed - the 3CX system is Debian and running in Google CP. The phones are both on the same network in the office. Both phones are Yealink T27P.

Have you traced with Wireshark per chance ?

Nossir - not done that. Interesting is if I set PBX carries audio for legacy phones in the extension setup then I get the audio but only after a delay which is annoying.

I've set up 3CX before and not had this issue so cannot see where I've messed up. Another interesting thing is if dialing from mobile to mobile extension this issue doesn't crop up and if dialing from any desktop extension to the mobiles it works fine too.

Many thanks for getting back to me so fast. Really appreciate it.

Cheers
Chris

 

[leejor]

Are they behind an SBC, or using STUN? If STUN, are they each assigned unique SIP ports? Have You tried setting the extensions to PBX delivers Audio as a work around? Is it just the two sets at that location?

 

[thames]

Hi Leejor

Been a while! Thanks for getting back to me. No - they all had the same SIP port (5060). I have now changed them to 5060, 5061 and 5063 and will retest tomorrow.

Edited this post to confirm they are using remote STUN and are not on SBC.

Cheers
Chris

 

[thames]

Hi again, Leejor

Seems like that might have resolved the issue for me. Many thanks.

Thanks for the responses, everyone.

All the best
Chris

 

[YiannisH_3CX]

Glad to see the issue has been resolved. Please note that when using multiple STUN devices behind the same public IP the option PBX delivers audio must be enabled for the extensions to be able to communicate between them. The reason why 3CX clients work is because they are using the tunnel to connect and the audio is going through the PBX anyway.
https://www.3cx.com/3cxacademy/videos/intermediate/configuring-remote-extensions/