[cisco-voip] easiest and quickest way to disable a PRI

[Pawlowski, Adam]

Last time I busied out bearer channels, I was not able to restore them to service without reloading the gateway, which was not ideal given I didn't want to bring everything down, but it was graceful. 

You could take it out of your route lists for outbound and shut it down after-hours, and just chance losing a call somewhere in there.

I also had luck changing the ISDN switch type on our emulated 5ESS to national which causes it to work for a while and eventually drop D and stop working which had the desired effect too. That is a bad idea and not recommended.