CLASSIFICATION OF COMPUTER NETWORK
Computer network can be classified into three. They are
- Network Classification Based on Geographic Proximity.
- Network Classification Based on Host Roles.
- Network Classification Based on Network Topologies.
Network Classification Based On Geographic Proximity
1) Local Area Network (LAN): The first kind of network based on geography is the Local Area Network or LAN. Local area network resides within a small geographic area. An example of a local area network would be the network inside a particular company or the network at our home. The Local Area Network is also referred as LAN. This system spans on a small area like a small office or home. The computer systems are linked with cables. In LAN system computers on the same site could be linked. The primary usage of local-area networks (LANs) is the sharing of hardware, software, or information, such as data files, multimedia files, or electronic mail. Resource sharing provided by local-area networks improves efficiency and reduces overhead.
2) Wide Area Network (WAN): A wide area network is a group of interconnected LANs, Local Area Networks, that are separated geographically. A Wide Area Network or WAN is a type of networking where a number of resources are installed across a large area such as multinational business. A wide area network (WAN) is a telecommunications network, usually used for connecting computers, that spans a wide geographical area. WANs can be used to connect cities, states, or even countries. Through WAN offices in different countries can be interconnected. The best example of a WAN could be the Internet that is the largest network in the world. In WAN computer systems on different sites can be linked. For example, a company can have offices at different cities.
WANs are either point-to-point, involving a direct connection between two sites, or operate across packet-switched networks, in which data is transmitted in packets over shared circuits. Point-to-point WAN service may involve either analog dial-up lines, in which a modem is used to connect the computer to the telephone line, or dedicated leased digital telephone lines, also known as “private lines.” Analog lines, which may be either part of a public-switched telephone network or leased lines, are suitable for batch data transmissions, such as congruent order entry and point-of-sale transactions. Dedicated digital phone lines permit uninterrupted, secure data transmission at fixed costs.
Point-to-point WAN service providers include both local telephone companies and long distance carriers. Packet-switched network services are typically chosen by organizations which have low volumes of data or numerous sites, for which multiple dedicated lines would be too expensive.
Network Classification Based On Host Roles
1) Peer-to-Peer: In a peer-to-peer network, there are no dedicated servers, and there is no hierarchy among the computers. All the computers are equal and therefore are known as peers. Each computer functions as both a client and a server. In a peer-to-peer network, all computers are considered equal; they all have the same abilities to use the resources available on the network. Each computer can function both as a client and a server. Computers are not dedicated to function as servers. They use the network to share resources among the independent peers. The computer whose applications are required by the other networked computers functions as a server.
A peer-to-peer network is a small group of people using a network. Peer-to-peer networks members usually perform similar tasks, which necessitates the sharing of resources. The peer-to-peer networks support 10 computers. Peer-to-peer networks have weak and intrusive security because a central server is not used to administer and secure the network. A peer-to-peer network does not support a central login process. This implies that a user who logs on to one peer can access any shared network resource, which is not controlled by a specific password. Peer-to-peer networks are relatively simple.
Advantages of a peer-to-peer network
- Less initial expense – No need for a dedicated server.
- Setup – An operating system (such as Windows XP) already in place may only need to be reconfigured for peer-to-peer operations.
Disadvantages of a peer-to-peer network
- Decentralized – No Centralized server.
- Security – Does not provide the security slit available on a peer-to-peer network.
2) Client – Server Based Networks: In a client server network, unlike a peer-to-peer network, network hosts have specific roles assigned to them. We have certain systems, certain hosts that are assigned to be servers. A server provides network resources. On a client-server network we also have clients or workstations. Server provides the resources and the client uses resources. In a client – server based network, clients rely on the services that the server provides, such as file storing and printing. Client computers are generally less powerful than server computers. A server-based network using network operating system is that the networks are organized into domains. A domain is a collection of networks and clients that share security information. Domain security and logon permissions are controlled by special servers called domain controllers. Users cannot access the resources of servers in a domain until a domain controller has authenticated them.
Advantages of a client- server network
- Centralized: Resources and data security are controlled through the server.
- Security: More security then Peer-to-peer network.
- Flexibility of operation: New technology can be easily integrated into system.
- Inter – operability: All components (client /server) work together.
- Accessibility: Server can be accessed remotely and across multiple platforms.
Disadvantages of a client – server network
- High Setting Up Cost: Requires initial investment in dedicated server.
- High Cost of Maintenance: Large networks will require a staff to ensure efficient operation.
- Dependence: When server goes down, operations will cease across the network.