4 - Carrier Ethernet Networks

Abstract

This chapter describes how communication industry came together to leverage benefits of Ethernet technology by defining and standardizing Ethernet services, making them reliable and scalable and specifying QoS and service management. This step was essential to make Ethernet-based services carrier grade. This chapter presents definitions of carrier Ethernet, carrier Ethernet networks, UNI, and EVC and describes associated terminology. The chapter also covers Ethernet service types, service attributes, and parameters and method to deliver QoS by traffic engineering which in turn is based on queuing, scheduling, policing, shaping, and stipulating performance parameters. Queuing and scheduling are defined by class of service (CoS), policing is defined by bandwidth profile, and performance parameters are defined by frame delay (latency), frame delay variation (jitter), frame loss probability, and availability. Description in this chapter also includes the need for service management related to network operation, administration, and management (SOAM) functions for fault and performance monitoring to ensure that QoS is in compliance with the SLAs. All the description in this chapter is based on the assumption that CENs belonged to one carrier or service provider, and therefore the customer was always an on-net customer. The chapter provides a transition to cases where customers are off-net customers requiring peering of CENs belonging to different carriers. This peering of CENs is the topic of Chapter 5.