Preface

The server guys just came in the room and said it's your problem: the network is slow. People have been calling the help desk since early this morning (it's now lunch) complaining that the sales order application has been extremely slow or unreachable. You looked at your Network Management Station earlier on and noticed nothing particularly wrong. Yet, the server guys claim it's the network, not their servers.

Also seated in the room are your boss, her boss, and the boss's boss. Orders aren't being placed and everyone now seems to think the fault lies in the network; it's your problem now.

This is a common situation with people who design and manage networks. When something goes wrong, no matter what it is, the first reaction is to blame the network. Maybe the network is to blame for the problem, maybe it is not. To know for sure, you will need to have implemented some level of performance and fault management techniques that help you isolate the cause of a particular performance related problem.