Classifications of Networks-Part 3

Network Topologies

                                 A network Topology means, the physical arrangement of computers,devices and cables in a network.

Bus Topology  

In Bus topology network devices uses a common backbone in a linear shape to communicate in the network. All the devices should be attached with this single shared cable with an interface connector. The device, which wants to communicate send a broadcast message to all the devices attached with the shared cable but only the intended recipient will accepts and process that message.

Bus Topology

Advantages

1. Easy to setup a network.
2. Easy to expand.
3. Suited topology for small networks.
4. Less expensive compared to other topologies.                                  

Disadvantages

1.  Slower data transfer rate.
2. Cable length and number of nodes that can connected are limited.
3. If the backbone cable fails, the whole network will fails.
4. Heavy network traffic when number of nodes are increased.

Ring Topology 

Ring Topology

In this topology computers are arranged in a ring manner. That is every computer or devices in this network should have two neighbors for communication. All the communications will be in the same direction, either clockwise or anti-clockwise. 

                              FDDI (Fiber Distributed Data Interface) or Token Ring Technology can be used to implement Ring Technology. Ring topologies can be found in office, school or small buildings.

Advantages

1. Chances of collision is very low.
2. Better performance than a Bus topology.

Disadvantages

1. Failure of one computer or port can cause the whole network to fail.
2. Adding, moving or removing devices can affect the network.
3. Slower than Star topology under normal load.
4. It is difficult to troubleshoot a ring network.
5. Network cards are expensive compared to Ethernet cards and hubs.

Mesh Topology

Mesh Topology

In a mesh topology, each device in the network are interconnected to one another to provide an almost always up network connectivity. That is each device remains in the network even if one or two of the connections go down. As this topology is difficult and expensive to configure, it is not commonly used in most computer networks.

Advantages

1. Data can be transmitted from one node to many nodes and vice versa simultaneously.
2. Less traffic problems.

Disadvantages

1. Configuration of network is complex and expensive.
2. Difficult to manage the network.

Star Topology

Star topology is the most commonly used topology in LAN. A star topology links the computers by individual cables to a centralized connectivity device, usually a hub or switch. The commonly used cable is the Unshielded Twisted Pair (UTP) or Shielded Twisted Pair (STP).

Star Topology

Advantages

1. Easy to setup and expand the network. 
2. Adding, moving or removing devices will not affected to the entire network.
3. Better performance than other topologies.                  
4. Failure of one device or link will not affect the whole network.
5. Centralization of network will help to analyze the traffic.
6. Easy to troubleshoot.

Disadvantages

1. Dependency to the central device(Hub or Switch) is the main drawback. If it fails, the entire network goes down.
2. Expansion and performance of the network is depended on the capacity of the central device.
3. Need of the expansion devices(Hubs, Switches or Routers) will make the network expensive.

Classifications of Networks-Part 2

According to Geographical conditions

• LAN (Local Area Network) : A Local Area Network covers only a localized or small physical area such as Home, Office, building or a small groups of building such as a school, or an airport.A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LAN's, and to the Internet or other WAN.Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, Network adapters, and Hubs/Switches. Wireless LAN and other more advanced LAN hardware options also exist.

Local Area Network

• MAN (Metropolitan Area Network) : A MAN is simply a network which interconnects a number of  Local Area Networks (LAN's) using a high-capacity backbone technology, such as fiber-optical links and spans a city or a large campus. A MAN often provides

Classifications of Networks - PART 1

                                    Networks can be classified into many according to its different characteristics. We can mainly divide networking into two categories,

• Wired Networking :  Wired networks are established by connecting computers or devices using some type of networking cables such as UTP (Unshielded Twisted Pair). Wired networks provide users with plenty of security and the ability to move lots of data very quickly. Wired networks are typically faster and reliable than wireless networks, and they can be very affordable. A notable drawback of wired network is that the cost of cables will make it expensive when more computers are added to the network. It can also make problems with the wires, because it can greatly limit the mobility of devices.

Wired Network

• Wireless Networking : Wireless networks are those which uses radio waves instead of cables to for computers to communicate. It is easiest and least expensive way to connect the computers, but slower and less secure compared to wired. They are more flexible than the wired networks because of the absence of physical wires.

Wireless Network

What are networks ?

Network

                       In the word of computers, a network is the connection or linking between two or more computers or devices for the purpose of sharing resources (software and hardware). Nowadays almost all sort of offices or buildings - small or large - around the world has even a small network. And the upcoming trend of Home Networking really shows the need and growth of networks today.


Minimum Requirements of a Network

• Two or more individual computer systems with network interface card(s).
• The computers should have network supporting operating system.(Eg: Windows XP, Windows 7, Linux)
• A communication media.(wires or air/space)
• Rules or Protocols to control a network communication.(Eg: TCP/IP)