Gizmo + SIP Adapter = Duh!

I was browsing the web yesterday when it hit me - I still have that D-Link SIP adapter!

Let me explain. I used to have AT&T CallVantage (home VoIP service). I liked the features, but the quality just wasn't that good so I canceled it early this year. Of course, I kept the VoIP gateway they sent me (a D-Link DVG-1120M).

And today it hit me - use that with Gizmo/SIPphone and have an always-on free internet phone! Why didn't I think of that before? I hooked it up and went under da' hood, only to found that cheap AT&T set a username and password for advanced options so you can't use it with any other VoIP service. That's a cheap way of getting buisness.

I started searching online. I found one username/password for a newer version of my adapter, but that didn't work on mine. I spend about an hour of googling, but I found no other username/passwords.

So, I consulted the SIPphone forums. A fellow user pointed me to a geocities site that had the SIPphone firmware for my SIP adapter. SIPphone keeps it unlocked, so that's good for me. In order to apply the firmware on this (and I think any D-Link device) is to set up a TFTP server and it will download it directly from your computer. Nice, I guess, but I like the way Linksys does it much better.

Included in the ZIP package is a Windows exe, a couple firmware files, and a readme. But, before I could upgrade the firmware, I need the administration panel...

Another user told me that if I did a hard reboot (hold the 'reset' button for over 1 min), then that may reset the password. I just thought "That's so simple, it'll never work" and boy was I surprised when it did. You'd think AT&T would have a more clever factory reset, but they don't. Oh well, I can log in with admin/admin now and get at the administration panel.

I was hoping that if I could get this far, I wouldn't need a firmware upgrade. But now, AT&T has reached an all-time cheapness. The firmware installed on it will not allow you to configure the SIP settings. So, I'm stuck with their service unless I upgrade the firmware for it (which I luckily can do).

No problem, right? Just set up a TFTP server and send it... wrong. I could not actually get a TFTP server working. tftpd didn't work at all, atftpd ran but I couldn't get it working, and tftpd-hpa didn't work. I spent a few hours trying all three of these things, but none of them worked. The only machine in the house that has Windows is my main desktop, but that is downstairs on a wireless connection.

Why is this a problem? My adapter has two ports: one for the Internet and one for a computer or router. Since my main desktop is on a wireless connection, I didn't think it would work because it was behind a NAT.

The obvious answer... forward ports. I'm so stupid. I forwarded port 69 to my computer, booted up Windows and ran the D-Link mini tftp server. To my surprise, that worked right away. I think this is the first time a server has worked perfectly in Windows the first time while I was fiddling around for hours on Linux and still couldn't get it working.

Regardless, I configured it to work with SIPphone, rebooted it and it worked :) Connected directly to the internet, I can make and recieve SIP calls with great clarity (better than CallVantage, though still using the same device).

But after I get something working good, it's time to complicate it.

My first plan was to hook it up to my unused ethernet port on my computer, but that would create a double NAT and probably wouldn't work. Also, it would only work when the computer is on.

So... I picked up an 802.11b ethernet bridge that was laying around (yeah, I have lots of little gadgets) and hooked it up. I plugged the D-Link into my computer directly and configured it to use a static IP and then configured the router to set up a DMZ on that IP. I plugged the box into the wireless bridge, waited a moment (untill it 'clicked', if anyone else has a similar box) and dialed 411. To my amazement, it worked the first time.

With all this success, I discovered a problem. Because this is an old model (like a year), the firmware is also old and doesn't support STUN (for those of you who don't know, STUN is a way for a device or application to discover it's real internet IP addres when it's behind a NAT and can't tell itself). Because of this, I cannot recieve calls. I don't think this will create a huge problem, though, because I am usually the one calling other people.

Stay tuned, more to come.