Implementation Evaluation Motivation User processes are not billed for kernel resources. Single principle for process and activity. Just wrong for multi-threaded server, performing activities on behalf of lots of different principles. Server Models Server waits on a well-known port.
Messages arrive and are routed to the application via accept.
Server waits for the actual request. Server processes request. Server sends response. Process model Fork a new process for each request. Keep a pool of processes around and dispatch to them.