One of the things I really like about my Nokia E61 is that it’s not just a cell phone, it’s also a VoIP phone. It includes a SIP client that works with Asterisk, mostly, so I’m able to get by with just one phone at home–incoming calls headed to either my cell number or my home number ring to the same phone. Which is great.

Except it all stopped working when I upgraded to the latest E61 firmware a couple months ago. I re-created my SIP settings, but the phone just wouldn’t register with Asterisk. Deleting and re-creating the settings didn’t make much of a difference, and eventually I decided to put off debugging it and wait until I had more time.

So, this morning I spent about an hour and a half trying to fix the phone. I re-configured it using several different configs that I found on line, and none of them worked. They all just generated “Registration Failed” messages on the phone. So I turned on SIP debugging in Asterisk, but it wasn’t very helpful–it didn’t show the phone trying to register at all. So I fired up tcpdump and discovered that the phone wasn’t actually sending any SIP requests at all–it was failing locally without ever talking to the network at all.

So I did a bit more digging, and found a Nokia forum comment that suggests that the upgrade from firmware 2.x to 3.x corrupts the SIP settings, and simply deleting SIP configurations won’t fix it. The poster recommended deleting SIP connections before upgrading, and then re-creating them after.

That isn’t an option for me anymore–I can’t downgrade the phone back to 2.x–but a simple backup/restore cycle (using the built-in backup to memory card option) fixed everything. It took about 10 minutes, but my E61 is now registering with Asterisk again.