This past month we have received a handful of reports from long-time iCam users who are suddenly having problems connecting via AT&T's 3G network. In troubleshooting one user's issue, we discovered that my iPhone was able to connect via AT&T 3G to their iCamSource, but Jay's was not.
In looking through the iCam Broker Server logs we were able to see that Jay's iPhone was connecting to AT&T's 3G network in a way that was much more "complex" than mine. Since iCam's zero-config connection logic depends how complex the iCam and iCamSource networks are to function correctly, a significant change in the complexity of AT&T's 3G network is going to have an effect for some users where things used to "just work" without any additional configuration.
This was also an issue back when iPhone OS 3.0 came out ... AT&T's 3G network was pretty basic with iPhone OS 2.x, but with iPhone OS 3.0 the connections became more complex, causing connectivity issues for some users. Now it looks like AT&T's 3G network is starting to transition to an even more complex network structure, and they may be rolling it out in different markets around the country.
The only difference between Jay's iPhone and my own (at least as far as we can tell) is where they are physically located: Mine is in Central Arizona, and Jay's is in Southern California.
One way to determine whether your iPhone is connecting via the "older, moderately complex method" versus the "newer, extremely complex method" is to visit
http://whatismyipaddress.com/ in Mobile Safari from your iPhone when it is connected via 3G. If the reported IP address starts with "166" then it is most likely the "moderate" network. If your IP address starts with "198" then it is most likely the "extreme" network.
In our testing we were able to replicate the situation where my iPhone could connect to a test iCamSource via 3G where Jay's could not, and the only thing that we needed to change was to tick the "Auto-Config Router" checkbox in the iCamSource, so depending on your router you may have to enable UPnP or manually forward a range of ports to get things working again if your phone starts connecting via the "extreme" method. Luckily the iCam "zero-config" connection logic does still work with some routers (like the newer Apple AirPorts) even when the iPhone is connecting via the "extreme" method, so your mileage may vary.
The reason for this forum post is to 1) Notify our users of a potential change to AT&T's network that may effect iCam's ability to connect without any additional configuration, and 2) To try and determine the scope of the change. Since this appears to be an AT&T-specific issue, Verizon and other carriers around the world probably will not be effected. It's really too early to say at this point, but if you are on AT&T in the US and would like to help us gather more information, we would greatly appreciate it. If you could reply to this post (or e-mail us at
support@skjm.com) with:
1) Whether your external 3G IP address as reported by
http://whatismyipaddress.com/ starts with "166" or "198"
2) Where your general geographic location is in the United States (City & State)
We may have more questions as we go along, but for now that's a good starting point.
Thanks!
UPDATE : We now have confirmed reports that even some 166.x.x.x IP addresses are also part of an "extreme" network. (These networks are in California and Florida.) I continue to see a 166.x.x.x IP here in Arizona that is still "moderate" as we continue to monitor this situation.
UPDATE #2 : I am now seeing "extreme" network 166.x.x.x IP addresses here in Arizona, so it looks like AT&T is continuing its roll-out to different parts of the country.