Strange behavior - No income voice if others call me

[yankai]

My FPL phone has been working fine for a long time.
Started from today, if others call me, they can hear my voice, but I cannot hear theirs.
If I call them, the two way conversion is fine.

Any idea what's going on?

I'm using Linksys ATA, and I followed the document from other thread to set it up (refreshed it again, didn't help).

Thanks

[liferunner]

Try this:
Login into the Voip Modem (ATA) interface, click Admin, click Advance view.
Click SIP. Under NAT Support parameter- set the following:
Send Resp to Src Port : YES
Stun Enable: YES
Stun Server: Stun.counterpath.com
or Stun.3cx.com
or Stunserver.org
or any valid stunserver
Click Save.
Good Luck!