Quincy Center for Technical Education
Computer Technology Department

The Three Basic Topologies
  • The Star Topology is common to ARCNet (Attached Resource Computer Network) networks. Every node in a star network is directly connected to a central server, giving it a starburst look. You have to use a bit of imagination and be willing to visualize all the nodes arranged around the server, instead of the reality that they are all located to one side a resemble one-half of a daisy. See Figure #1


    Figure #1

  • The Ring Topology, which is known more commonly under its commercial name of IBM's Token Ring, creates a network structure in which all the nodes are connected one to another to form a loop that starts and ends at one of the nodes, possibly the server. Like the star, you have to use some imagination to create a ring from the connected nodes. See Figure #2


    Figure #2

  • The Bus Topology, or Ethernet networking, is the most common network topology in use. If the star truely is a star, and the ring is really a ring, the Ethernet networks are installed in a straight line, called a backbone. I think it's called a backbone because after you attach all the nodes to the main Ethernet line, it resembles the skeleton of a dead fish ------ without the head, of course. See Figure #3


    Figure #3



Focusing on the Fundamental Features
      Networks have essentially five parts: NICs, cables, connectors, and a network operating system (NOS). For the A+ exam, you are primarily concerned with the NIC card and how it is configured and installed into a node (a PC, printer, or other network-capable device). You also need some understanding of the different cable types and how they connect to the NIC card. If you know that a network has a NOS, that should cover that part.