For several years I had call forwarding setup so that when my cell phone was turned off ("unavailable") the call would be automatically forwarded to another extension. For some reason this stopped working several months ago. I messed around with the settings, but nothing seemed to work. I am not sure if the problem is mine or if the problem is with PBXes, but since it used to work and now it doesn't I don't think it is a problem that I created.
In the pbxes settings for the extension that rings my cellphone, under the call forwarding section where it says "If unavailable", I have entered "SIP/*******" where the ******* is my extension name. Shouldn't this work?