The following points summarize the key concepts in this chapter:
What Is a Network?
- The primary reasons for networking are to share information, to share hardware and software (reducing cost), and to centralize administration and support.
- A local area network (LAN) is the smallest form of a network and is the building block for larger networks.
- A wide area network (WAN) is a collection of LANs and has no geographical limitation.
- Networks are classified into two principal groups based on how they share information: peer-to-peer networks and server-based networks.
- In a peer-to-peer network, all computers are equal. They can either share their resources or use resources on other computers.
- In a server-based network, one or more computers act as servers and provide the resources to the network. The other computers are the clients and use the resources provided by the server.
- Features of the two major network types are summarized as follows:
Comparison of Network Types
|Consideration ||Peer-to-Peer Network ||Server-Based Network |
|Size ||Good for 10 or fewer computers ||Limited only by server and network hardware |
|Security ||Security established by the user of each computer ||Extensive and consistent resource and user security |
|Administration ||Individual users responsible for their own administration; no full-time administrator necessary ||Centrally located for network control; requires at least one knowledgeable administrator |
- The physical layout of computers on a network is called a topology. Topologies can be physical (actual wiring) or logical (the way they work). There are four primary topologies: star, bus, ring, and mesh.
- In a bus topology, the computers are connected in a linear fashion on a single cable. Bus topologies require a terminator on each end of the cable.
- In a star topology, the computers are connected to a centralized hub.
- In a mesh topology, all computers in the network are connected to one another with separate cables.
- In a token-ring topology, the computers are connected physically in a star shape, but logically in a ring or circle. The data is passed from one computer to another around the circle.
- Hubs are used to centralize the data traffic and localize failures. If one cable breaks, it will not shut down the entire network.