Solved No sound for some internal calls

[KleiDav]

Hi

We have an hosted 3CX, latest version, with 4 Yealink T46S phones.

3 of the phones can't call internally each other, it does ring, but no sound.
What's strange is that one (and only 1) of the extensions can call and be called by all the others, sound is OK.
The extensions and phones have the exact same configuration...

 

[Saqqara]

Are the phones configured using stun ?

Have you configured different ports for the phones -

https://www.3cx.com/community/threa...etgear-nighthawk-x4s-d7800.54620/#post-225296

 

[KleiDav]

So you mean I SHOULD configure different ports manually for each phone, 1 by 1?
And why is 1 phone able to call the others?

 

[YiannisH_3CX]

Hello @KleiDav

Please navigate to the extension settings and enable the option PBX delivers audio located under the Options tab.
The recommended method for setting up multiple STUN phone behind the same public IP is to use different SIP and audio ports and port forward those ports to the local IP of the phone.
This helps eliminate audio and signalling issues with firewalls and routers that do not handle these very well.

 

[KleiDav]

Thanks. You're right, 3 of the phones did not have PBX delivers Audio checked. It works now.
Didn't know it's prefered to do setup the ports manually. It's a lot of work ! (only have 4 phones here but I can't imagine working that way with customers that have 50 phones or more)

 

[leejor]

STUN is fine for one or two sets, anything more is best run over an SBC. Each sets port would then not have to be unique. With STUN, consider that each set is "seen" by 3CX as PublicIP and port, so it is the ports that differentiates each set, not an IP. Using PBX Delivers audio may solve the issue, but it creates additional traffic back to the PBX, as all voice must now go to and from, rather than direct from set to set, if that is a concern.

 

[YiannisH_3CX]

Glad to see the issue is now resolved. Please note that you need the option PBX delivers audio to all extensions that are provisioned using STUN.
As @leejor suggested you can always use an SBC for larger installations.