[Asterisk-Users] Zap channels stuck in 'Rsrvd' state

[Steve Creel]

I have two Adtran 750's connecting our analog phones to asterisk.  On
occasion, I get a channel that gets "stuck" off hook.  'show channels'
shows:

Zap/27-1  (longdistance s  1  )  Rsrvd (None)  (None)

And will just stay like that until the phone is manually picked up and
hung up again (or asterisk is stopped/started).  I guess this is a
function of an unclean hangup (being read as a flash instead of a
hangup?).  A 'soft hangup zap/27-1' will not do anything (though it makes
an attempt).

Does shortening the rxflash time sound like it may help this?  (Does
anyone have a good explanation, or link to one, of the prewink, wink,
preflash, flash, start, rxwink, rxflash, debounce timing functions?)

Thanks, as always...
Steve