Chapter Summary

The key points covered in this chapter are as follows.

Network Cables

There are three basic topologies used to connect LANs: bus, star, and ring.

• Coaxial cables have two conductors, use the bus topology, and are no longer in common use for LAN installations.
• Unshielded twisted pair (UTP) cable in the star topology is the most common network medium used today.
• Fiber optic cable uses light pulses for signaling instead of electrical voltages, and are resistant to many of the forms of interference that affect copper cables.

Network Interface Adapters

• A network interface adapter—generally a network interface card (NIC)—provides the link between a computer and the network medium.
• The network interface adapter and its driver implement the data-link layer protocol on the computer.
• NIC installation problems are most often caused by hardware resource configuration issues or device conflicts.

Network Hubs

• Ethernet hubs are also called multiport repeaters.
• Ethernet hubs forward incoming traffic out through all other ports simultaneously.
• You connect Ethernet hubs together by cabling the uplink port on one hub to a standard port on the other.
• Token Ring hubs are called multistation access units (MAUs).
• Token Ring MAUs forward packets out through each port in turn and wait for each packet to be returned.
• You connect Token Ring MAUs using the Ring In and Ring Out ports.