Extension dialing same lan hosted PBX

[maguirej]

I have seen two separate hosted accounts that have successfully communicated extension to extension dialing within the same lan on a hosted account. They have worked flawlessly until a recent Yealink firmware update (66.86.0.5). I do not know if this is linked, but occurred near the same time.

The one client is a 5 phone shop on a hosted account. The other has 40 phones on one network separated by managed switches. Both worked without issue previously, but now does not work until pbx delivers audio is turned on. Even within the same managed switch, no audio. There is obvious reasons we would like to keep extension calling outiside the PBX in a hosted environment, if possible.

Extension to extension dialing outside the local lan works without issue.

Has anyone experienced this issue or overcame the local extension to extension trouble without "pbx delivers audio"?

 

[Naveen | Cal4care]

Hello Maguirej,

All the IP phones provisioned via 3CX SBC or Direct SIP(STUN-remote) method?

 

[cobaltit]

Clearly STUN because SBCs never have problems.

You didn't specify whether it's self-hosted or 3CX hosted, but since the makers of 3CX don't want to support STUN, I'm not sure why you would want to.

The answer, as it always is, is to use a SBC.

 

[JohnS_3CX]

Hi @maguirej

STUN left alone "tends to work until it doesn't" - often the final behavior is dictated by too many factors (switch, firewall, modem, ISP). You want to minimize these factors, or remove them from the equation if possible.

As @cobaltit rightly points out, the correct answer here was always to use a 3CX SBC for hosted installtions. It achieves exactly what you want (audio traffic stays local), and provides extra benefits on top of that like: PnP provisioning, TLS encryption, basic monitoring, removes need to keep static IPs and port forwards, can bypass roadblocks and interference from firewalls, modems, ISPs.

A low-cost Raspberry Pi can act as an SBC for up to 50 extensions
https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/