Why the iPhone is better (and worse) than BlackBerry
He suspects that my Blackberry worked simply because of its lack of maturity…
It “stupidly” (but as instructed) waits the pause delay time and then sends the DTMF. Unfortunately the iPhone, and many more wireless phones, do not start the delay timer until AFTER the connection is made because they’re “smart”. This is actually an improvement because the time from dial to connect can vary greatly. As an example a delay time that is fine for, say, AT&T here in South Florida might be completely useless when roaming because it starts the DTMF string too soon (e.g. the connect takes 7 sec. while roaming instead of the 2 sec. at home).
Therefore, since the Sprint network is BROKE [Dan's emphasis] (they don't send the "connect" message) the iPhone is patiently waiting while the "dumb" RIM just sends the DTMF hoping it was timed right (which it was).
On most phones one could program "wait" in the number string ("w" instead of ",") and the handset waited for the user to send the DTMF string by pressing a button on the phone (or, if I remember correctly, could be triggered by a tone from the dialed number – sprint does this on their 800-877-8000 number). Unfortunately there is nowhere in the iPhone UI to do this.
SO…the conclusion is
1) the RIM device worked because it was behind the times
2) Sprint is too dumb to send the "connect" message back to wireless phones
3) the iPhone is too smart for it's own good and not good at waiting (like a teenager)
There goes Steve Jobs telling all of us what we need and when we need it again
Thanks Dan. As an engineer myself, sometimes knowing why something doesn't work is almost as good as the thing actually working. But not quite.