Last week I gave Sprint some complements on their success avoiding customer service affecting fiber cuts. Unfortunately, Murphy took it as a challange. First, Sprint lost an STP power supply which blocked SS7 service in Sprint's southeastern network for 2 hours and 52 minutes. Then on Tuesday, Murphy killed a disk drive on Sprint's SCP, blocking Sprint's nationwide network for 4 minutes until it could be taken out of service. Maintaining 99.999% network availability is hard for any network, telephone or the Internet. But sometimes I wonder what the real requirement is. The Australian stock exchange went down for a few hours, it wasn't the end of the world. Sprint had some more blocked calls than normal, most people didn't notice. Are we setting artificial performance requirements, which don't reflect reality? Either in what can be achieved, or is necessary.