So we will keep it very simple:

First off, I recommend firmware version 8.3.1. It’s the version we use and it seems to have the least bugs out of all the releases for these phones. Most new features seem to cater to Cisco CallManager features more than they do Asterisk, so let’s forget all about any versions after 8.3.1 for now!

Second, you will need to edit SEP$MAC.cnf.cml ($MAC being the mac address of your phone) and find the line that has this key:

 

<messageWaitingLampPolicy>0</messageWaitingLampPolicy>

You will want to change this to 1. There are more options that allow you to fine-tune this, however, I find this best. 1 will make the envelope blink next to the line that has a new voicemail, and will make that light shine so bright!

Now, we have one more step to make this work properly, which can be done two ways:

• Edit sip_custom.conf and add the following line:

buggymwi=yes

Save the file, reload asterisk.

OR:

• In FreePBX, click on the tools tab, go into SIP Settings (where you change up the NAT settings) and at the very bottom of the page, put in the above setting in the field for extra SIP options. Save, and reload.

You will almost immediately see a change if you already rebooted the phone, if not, well, reboot your phone!

Now go ahead and leave a voicemail and watch the indicator light up!

Some additional notes: You may notice a strange behavior where your dial tone will blip on and off when you start a new call if you have voicemail. This is intended and set as a default in some configs. If you find this annoying, go ahead and open up your SEP$MAC.cnf.xml file and find the following line:

<stutterMsgWaiting>1</stutterMsgWaiting>

and change it to 0. Reboot the phone, and the behavior should go away.

If you have any questions or comments, feel free to leave a few comments.

While attempting to convert a couple of Cisco 7941G phones from the SCCP-8-5-4  to SIP, I encountered an “Auth Fail” message after performing a factory reset on the phone.  The “Auth Fail” message was displayed while attempting to download the term41.default.loads file.  If you haven’t reset the phone, you can encounter the error when the phone is attempting to download the SEP{mac}.cnf.xml file.

It turns out that the latest SCCP firmware is unable to authenticate the latest SIP image that I’m trying to install on the phone.  In order to get past this, you’ll need to downgrade the phones current SCCP firmware to sip.8-5-2.  After that, you can upgrade to the another version if you like.

Unzip the 8-5-2 firmware into your tftp directory and overwrite the term41.default.loads and term61.default.loads.  Reset the phone and it will load the term41.default.loads file.  The term41.default.loads file will cause the phone to “upgrade” to the 8-5-2 firmware.  When the phone reboots from the firmware update, it will load the SEP{mac}.cnf.xml.  This is where you want to specify the firmware version that you’d like to end up with.  This time, you won’t get the ”Auth Fail” error.

Complete these steps:

1. Cycle the power of the phone by unplugging the power cord and then plugging it back in. If your phone is powered over Ethernet, unplug the network cord and plug it back in.
2. The phone will begin to boot. Immediately press and hold # while the Headset, Mute, and Speaker buttons flash in sequence. Release # after the Speaker button is no longer lit.
3. The line buttons flash in sequence in order to indicate that the phone waits for you to enter the key sequence for the reset.
4. Press 123456789*0# within 60 seconds after the Headset, Mute, and Speaker buttons begin to flash.
   You must complete this key sequence within seconds or the Headset, Mute, and Speaker buttons will stop flashing and the phone will continue its normal boot process and the phone does not reset.
   If you enter an invalid key sequence, the buttons no longer flash, and the phone continues with its normal boot process. The phone does not reset.If you enter this key sequence correctly, the phone displays this prompt:
   upgrading

If you want to complete wipe the phone of its current firmware, hard reset using 3491672850*# instead of 123456789*0#   The extension lights will flash red and then the phone will take the firmware defined in your termXX.default.loads file.