GigabitFiberEthernets(OpticalEthernet).docVIP

Technology Task Group 5 Gigabit Fiber Ethernets (Optical Ethernet) Introduction This report provides an analysis of the Gigabit Ethernet technologies (1 Gb and 10 Gb Ethernet), which we will refer to as “Optical Ethernet.” We discuss Optical Ethernet network architectures and capabilities, emerging EtherLEC carrier activity, and an overview of related (competitive and synergistic) technologies. Optical Ethernet technology may produce profound changes in network architectures and underlying network technologies, and it has the potential to make significant inroads into the MAN/WAN environments. We therefore examine the Optical Ethernet technologies from the viewpoint of trying to answer the underlying question, “Is Optical Ethernet a viable MAN/WAN technology and will it play a significant role in future network architecture evolution?” Ethernet Background Figure 1 shows the Ethernet protocol stack and its relation to the OSI Model. In OSI terms, Ethernet provides layer 2 (Data Link) and layer 1 (Physical) functionality. The parts of the protocol stack that are specific to Ethernet are shaded (the MAC, Physical Signaling, and Media). The Logical Link Control (LLC) sub-layer defined in IEEE 802.2 and MAC Bridging defined in IEEE802.1 are independent of any specific LAN technology and sit on top of the Ethernet specific stack. The LLC performs error control, broadcasting, multiplexing, and flow control functions. We do not go into the details of the LLC here since they are not important to understanding Optical Ethernet capabilities vis-à-vis it being a MAN/WAN technology. The IEEE 802.1D protocol is an important protocol we discuss. This standard defines the MAC Bridging capability. Important supplements to 802.1D are also discussed like 802.1Q and 802.1p, which cover VLANs and priority capability for 802 LANs. The other protocol specification we discuss is the Ethernet standard IEEE 802.3. The current version (2000 edition) includes all of the major supplements rele