I'm still bugged by that T3 comment. I know most of you are thinking about facilities, but he could have been referring to the LAPB T3 timer. Yeah...remember that from the Frame Relay days? Well it's used in all kinds of stuff from VoDSL to NFAS PRI circuits.
It's a "watchdog timer"--as I like to call it--which says, "how long do I wait to hear from the other end before I claim that the link is down and bounce this circuit?"
Kinda makes sense here, although it might be a red herring. It would be neat to know how exactly it is that the carrier is delivering this PRI.
