Urgent: 3CX+ Yealink Sim gateway. Callers can’t hear us properly but we can hear them perfectly.

[Ife Adejumo]

We have a Yealink TG400 sim gateway (4 SIM cards) and I successfully connected it to 3CX 3 weeks ago. We tested and had perfect quality.

2 days ago callers (inbound or outbound) couldn’t hear us well when we spoke, there was a lot of breaking- they could only hear every other word, but we could hear them perfectly with no delays or loss in signal quality.
I’m currently using all default settings. Please help.

Client Phones are a mix of Yeastar T42S and T46S

 

[eddv123]

You mean Yeastar TG400 and Yealink T42S/T46S.

I don't think this is a 3CX issue, I would look at the gateway (which unfortunately is un-supported). Perhaps run a Wireshark trace and analyse the audio.

Obviously this is not a fixed line connection so audio quality is going to be effected based on coverage.

 

[leejor]

If you have a spare ATA sitting around, you could program it to register direct with the Yealink gateway (unplug the 3CX server Ethernet during off hours), and place calls out on each trunk to test call quality. That would eliminate both 3CX and the Yealink sets from the equation.