SPA9000 one-way audio only with FXS Analog Phones

[CarlosMtnez]

Hi, I have a SPA9000 woking fine with IP Phones. External and Internal calls. Outbound and inbound.

I have no router in front, so no NAT or FW problems, SPA9000 is connected directly to a DSL Modem in WAN interface and then I have a Switch in LAN interface.

But my problem is with FXS Analog phones connected, When an external calls incoming if I configure SPA9k to rings FXS1 extension I have a very weird behavior, Sometimes when I pick up the phone it doesn't takes de call the first time, when finally connected the audio is only one-way (They can hear me, but I cannot hear them). Only a few times the audio is both ways.

IP Phones are working fine, the problem is only with FXS Analog phones.

Regional Settings was configured correctly acording with my location. I'm from Spain.

I tried different Phones, with the same result.

I attach some screenshots of Regional tab and FXS tab:

Many thanks in advance.

[CarlosMtnez]

I forgot to say that Internal calls between IP Phone (softphone X-Lite) and analog FXS Extension are fine and OK, both ways sound.

So, the problem is only with External calls and FXS Analog phone.

Thanks in advance.

Regards.