that is typicall of when the G700 can ping the MGC list, but it is waiting for the "mg recovery" rule timeout to occur. You may need to update the firmware on the G700, some of the older firmware may not work properly with the media gateway time out timers.
if you display the media gateway (display media x), there shold be a "recovery rule" listed, you can see what is in the rul via "display sys mg x" where x = the rule #
the minimum timeout is also 3 minutes of network stability
Mitch
AVAYA Certified Expert