Cisco 7940 registration failure


I’m trying to get my Cisco 7940’s working with FreePBX Distro v 3.211.63-10. My searches have yeilded quite a few threads regarding Cisco 7940’s not working properly, but not much difinitive information on fixing them.

I did have the phones working successfully with Trixbox 2.6, before upgrading to FreePBX Distv3.211. SIP Firmware 8.12 is installed.

After installing the FreePBX distro, using the End Point Configuration Manager, I installed “Cisco/Linksys”, and clicked “Enable” for 7940.

In the End Point Configuration Manager, I filled in the MAC address, choose Cisco 7940, selected an extension, and clicked ADD. The phone boots up, pulls TFTP configuration, pulls the correct SIP server, and correct extension information.

When the phone tries to register, the asterisk console shows:

NOTICE[1793]: chan_sip.c:27829 handle_request_register: Registration from ‘sip:[email protected]’ failed for ‘’ - Wrong password

Global SIP is set for:
IP=Static IP
External IP (my external IP)
Local Networks - all private subnets

The phones are on the same switch as the PBX.

Extensions are at all DEFAULT settings (NAT=NO-RFC3581, qualify=yes). I tried NAT=NEVER on the extension, and it made no difference. Some threads indicated that nat=no doesn’t work, and to set nat=never. I found that it had no impact at all.

Any tips or advice? I feel like I’m just missing some kind of basic setting or something.

Do you have all of your networks defined under localnets in sip.conf? If you don’t Asterisk will try and NAT