4
Carrier Ethernet
In the 1970s, a group of engineers at the Xerox Corporation gave the name Ethernet to a coaxial cable, local area network (LAN)1 that used packet transmission. It was developed further by a consortium of Digital Equipment Corporation, Intel Corporation, and Xerox Corporation. In 1985, the Institution of Electrical and Electronic Engineers (IEEE) promulgated a standard (IEEE 802.3) for the data link and physical layers. It has been revised and expanded as Ethernet evolved to support higher speeds, additional network media, and other configurations. In the process, Ethernet became the dominant technology for local area networks. This success led to applications in other networks. In fact, the protocol stack of TCP/IP and Ethernet (Link layer) enables multimedia services to be transmitted throughout the entire Internet. The Ethernet family includes links that:
- Operate at speeds of 10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps, 40 Gbps, and 100 Gbps.2
- Employ coaxial cables, unshielded twisted pairs (UTPs), shielded twisted pairs (STP), optical fibers, and wireless.
- Are configured as buses, hubs, switched networks, point-to-point (P2P) and point-to-many (P2MP) connections, and combinations thereof.
Above 1 Gbps, because short frames may be too fast to be detected, extension fields are added to lengthen the frame. Further, to improve the throughput of high-speed networks, a burst mode was added. This allows a sequence of frames to be sent from the same source without relinquishing ...
