[cisco-voip] loop start signaling on an FXS port

[John Osmon]

I've got an IAD2431 running MGCP slaved to a Tekelec T6000.  It has
8 FXS ports tied to a Shortel PBX.  The Shoretel has a nasty habit of
releasing and grabbing lines too quickly -- so the IAD sees the 
transaction as either a flash-hook, or a continuation of the earlier
call.

We've tried to get the Shortel vendor to:
  - change the outbound hunting to prevent it from seizeing the line that 
    was just released
  - increase the time between releasing a line, and seizeing it again

The vendor claims that neither can be done, so I'd like the IAD to:
  - disable the ability to flash-hook (rather then just change the timing)
  - hold the line to zero volts for 3-5 seconds after a call is completed

I've been chasing this problem for a week or more, and can't find any
knobs to tweak on the IAD.  Anyone out there have any good ideas?