5.1 Cabling the LAN  
  5.1.2 Ethernet in the campus  

Ethernet is the most widely used LAN technology. Ethernet was first implemented by the Digital, Intel, and Xerox group, referred to as DIX. DIX created and implemented the first Ethernet LAN specification, which was used as the basis for the Institute of Electrical and Electronics Engineers (IEEE) 802.3 specification, released in 1980. Later, the IEEE extended 802.3 to three new committees known as 802.3u (Fast Ethernet), 802.3z (Gigabit Ethernet over Fiber), and 802.3ab (Gigabit Ethernet over UTP).

Network requirements might dictate that an upgrade to one of the faster Ethernet topologies be used. Most Ethernet networks support speeds of 10 Mbps and 100 Mbps. 

The new generation of multimedia, imaging, and database products, can easily overwhelm a network running at traditional Ethernet speeds of 10 and 100 Mbps. Network administrators may consider providing Gigabit Ethernet from the backbone to the end user. Costs for installing new cabling and adapters can make this prohibitive. Gigabit Ethernet to the desktop is not a standard installation at this time.

In general, Ethernet technologies can be used in a campus network in several different ways:

  • An Ethernet speed of 10 Mbps can be used at the user level to provide good performance. Clients or servers that require more bandwidth can use 100-Mbps Ethernet.
  • Fast Ethernet is used as the link between user and network devices. It can support the combination of all traffic from each Ethernet segment.
  • To enhance client-server performance across the campus network and avoid bottlenecks, Fast Ethernet can be used to connect enterprise servers.
  • Fast Ethernet or Gigabit Ethernet, as affordable, should be implemented between backbone devices.