to work around broken phones that fail to register when they should. I doubt his idea of 100% availability is the same as yours or he would/should be using a different brand/model of phones. + The mobile phone will survive a power outage, because of the register you could be behind NAT as it will open the bindings, you can take it to the bathroom etc. I'm just trying to illustrate the possible advantages of a register before XBbrian redoes his network config. Z