Nokia E71 - Suddenly can't register to FreePBX

So, everything was good. I was frolicking in a green, grassy field on a spring day doing little turny-dance moves with my Nokia E71 - because it was working perfectly with our home-brew FreePBX system. But then it stopped. Suddenly. Everything went dark and gloomy.

Here's what happened:

I registered just fine like usual on my home WIFI network.
I made a call to an extension using X-lite somewhere out in WAN-land
The call connected and the first few seconds were good. Then the call got choppy and disconnected. I was able to call back, but on the second call it dropped and from that point forward I was no longer able to register with our PBX.

To troubleshoot the issue, here is what I did:

1. Attempted simple web connection on E71 - success
2. Attempted to register to our PBX by using Fring's quick and easy SIP subscription and entering my extension information - success! <-- that one surprised me
3. Connect to extension and do a successful call using X-lite on a totally separate machine but in the same LAN. - success

So, I concluded that the router and home internet connection is not the problem (step #1 above) and that the PBX is not the problem (because Fring could connect). I also figured out that all the specific extension settings were ok by step #3. These are good steps to log for quick troubleshooting.

So the problem, then, MUST be related to my Nokia's built in SIP settings OR the actual WIFI connection.

I should note that my E71 was setup as a static IP in my router as well as in the Nokia's WIFI connection advanced settings (ask us if you don't know how to find those because they're really well hidden!)

As a first step, I completely erased all SIP setting profiles in my Nokia. I figured that I must have messed around with something and screwed them up. I re-entered them again the way that I knew they used to work according to this GREAT tutorial (http://www.geek.com/articles/mobile/feature-voip-with-nokia-e71-how-to-2008095/). - FAIL!

After much messing around with my router and DMZ, etc, and still not being able to do it, I decided to do something Disposable Joe once showed me in a coffee shop - completely erase the WIFI connection from the WLAN list. I just nuked it. Then, I re-scanned for available networks and re-added my WIFI connection. Of course, the default connection is dynamic (not static) but what was interesting was that my Nokia immediately registered to our PBX!

I did a test call and it was ok if I called out to another extension, but not if a call came in (they couldn't hear my voice). THankfully, I"m pretty sure this is just a port problem and once I set it up as static IP in my router again, it should work. Let's try!

Test 1a: E71 @ home > DJ @ Work = No problem.
Test 1b: DJ @ work > E71 @ home = just got my voicemail

Test 2a: E71 @ home > mom @ home = no problem
Test 2b: mom @ home > E71 @ home = she just got my voice mail

Confirmed problem is on my side, my router, my ports. Next test is to turn my phone back to a static IP to see if that magically fixes everything.

Step one, change E71's WIFI advanced settings to static and give it a unique IP tag
You'll need:
-to choose a unique static ip (I chose .107)
-to have your router's default IP address (dlinks are 192.168.0.1)
-to find your primary/secondary dns settings (found in your router somewhere)(in Dlinks under the 'status' tab)

Step two: set up your phone in your router as a Static IP device. I did this in my dlink under the DHCP button on the 'home' tab

Instant FAIL! Grrr

Ah HA! The classic problem (and all E71 users, please note)

In your SIP settings of your nokia, make sure it's 'always on' and not 'when needed'. I have no idea why, but this has caused us much headache before. Just memorize that it should be 'always on' and not the other. The other seems to be the default so if you wipe a profile/start a new one, I think it defaults to the one that doesn't work. As soon as I changed to 'always on' boom. It registered. Now to test as per above:

Test 1a: E71 @ home > DJ @ Work = success
Test 1b: DJ @ work > E71 @ home = fail!

Test 2a: E71 @ home > mom @ home = success!
Test 2b: mom @ home > E71 @ home = success!

So now I'm very confused. It seems to work with my mom but not DJ....

Hopefully I'll be able to follow up with some good news.