Globally, major network operators have incorporated network convergence into their strategy to grow service revenues and reduce capital and operating costs. Conv- gence occurs in applications (integrated messaging, voice over IP), in network control (portable numbers, SIP, mobile IP), in the transport layer, as well as in the access network. This convergence of networks means that various types of traffic flows, which have been carried by separate specialized networks, now share the resources of a single core IP-based network. In the access, the trends are towards fixed/wireless convergence as well as convergence of various wireless access technologies. Network convergence will be successful only if the quality of the individual s- vices is maintained in the new network environment without undue increased costs. The quality of service delivery is critically dependent on how network performance and availability, as experienced by the traffic flows, are managed. Managing traffic performance is a critical enabler for success. Reaching the desired performance levels requires adapting processes such as network planning, resource engineering, and network monitoring to the converged network milieu.