Network Cable

• Ethernet originally ran over coaxial cable, but it is now more widely implemented with Unshielded Twisted Pair, or UTP. The Ethernet standards are periodically updated to account for improved technology. The latest version describes the implementation of the system over UTP, tin-axial cable or fiber optic cable. Token Ring mostly runs over Shielded Twisted Pair cable, although UTP can also be used. A version of Token Ring technology uses fiber optic cable
  
  

Media Access

• Both methods are closely identified with their media access control methods. Ethernet uses a system called Carrier Sense Multiple Access with Collision Detection. Only one computer can transmit on the cable at any time, so each computer has to listen for silence on the line. In modern implementations, however, it is rare for many computers to be connected to the same cable. Token Ring uses an empty data packet that circulates around the network. Any computer wishing to pass data to another computer over the network fills the packet with data and puts the destination address in the header. The packet travels around the network until it arrives at the named address. The empty packet is the "token" referred to in the networking system's name of "Token Ring."
  
  

Topology

• The "ring" in "Token Ring" refers to the layout of the cable in the network. If computers A, B, C and D are connected together in a Token Ring network, a cable runs from computer A to computer B, a cable runs from computer B to computer C, a cable runs from computer C to computer D and another runs from computer D to computer A. Thus, a ring is formed. All data travels in one direction; each computer in the ring forwards incoming data packets if it is not the intended recipient of the data packet. Ethernet can be configured a a "bus,"which is one long cable to which each computer connects by a branch line. A more widely implemented topology for Ethernet, however, is the star LAN. In this plan, all computers connect to a central hub or switch.
  
  

Standards

• The Institute of Electrical and Electronics Engineers now has responsibility for both the Ethernet standards and the Token Ring standards. The IEEE organizes its work in working Groups; each of these groups has a code number, by which their standards are known. The Ethernet working group is 802.3 and the Token Ring working group is 802.5.