Hi,
we have CUCM 7 with ip phones using cisco router 2811 as voice gateway to make calls to PSTN through trunk of FXO's.
Sometimes there is sudden failure on the CO line connected to the FXO(the reason from PSTN), can we confiugre the router to discard the FXO port from being chosen during failure of FXO and let it back to work again incase of returning service to CO line.