I wonder if anyone had this problem. I use a Cisco ATA 186 with Asterisk. It works fine, except after a few days or weeks, it starts adding the @ sign in front of any number dialed, the only way to stop that is to reboot the device. I tried filtering out the @ in Asterisk, but then the Cisco ATA starts adding multiple @. (So when I dialed 201, the number sent to the Asterisk became @@@@201.) Very strange. I am running the latest SIP firmware 3.2.1.