Well, I finally got Facetime to work past the one minute "barrier" on two occasions today on 3G and using My3G. The first call was earlier in the day and it lasted over 5 minutes. The second call occurred five hours later. Here is the breakdown.
Phone: both are iPhone 4 using (4.0.1)
Carrier: both phones are AT&T
Wifi emulator: both phones are using My3G (4.2.5)
Call type: both Facetime calls were 3G to 3G
Location: Me in Northern California, My Friend in Southern California
Call #1 at 11AM
Me, standing outside in a parking lot away from structures, 4 bars, unknown download and upload speeds.
My friend, standing outside in a parking lot away from the tall office building where she works, 4 bars, unknown download and upload speeds.
Call duration was about 5 minutes.
Call #2 at 4PM
Me, inside my apartment using 3G, 4 bars, speedtest showing average download speed of 759 Kbits/s and upload speed of 504 Kbits/s
My friend, standing in the same spot as call #1, 4 bars, speedtest showing average download speed of 982 Kbits/s and upload speed of 476 Kbits/s
Call duration was 7 minutes 18 seconds using a stopwatch. Call duration does not include "Connecting..." time but actual video connection time. We ended the call because her break was over.
We ran the speed test seconds prior to initiating the second Facetime call.
We have been trying Facetime over 3G for several days, but the call would disconnect before the one minute mark. The only thing that changed today was that I told my friend to walk away from the tall building. This allowed the call to stay connected. I guess Facetime over 3G is finicky. You can't do it wherever you want. Conditions have to be optimal (strong signal) in order for the Facetime call over 3G to stay connected past the one minute "barrier."