Identifying Network Topologies

Identifying Network Topologies

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A network topology is the physical layout of computers, cables, and other components on a network. There are a number of different network topologies, and a network may be built using multiple topologies. The different types of network layouts are :

• Bus topology
• Star topology
• Mesh topology
• Ring topology
• Hybrid topology
• Wireless topology

Bus Topologies

• A bus topology uses one cable as a main trunk to connect all of the systems together.
• A bus topology is very easy to set up and requires no additional hardware such as a hub.

• The cable is also called a trunk, a backbone, or a segment.
• With a bus topology, when a computer sends out a signal, the signal travels the cable length in both directions from the sending computer.
• When the signal reaches the end of the cable length, it bounces back and returns in the direction it came from. This is known as signal bounce.
• Signal bounce is a problem, because if another signal is sent on the cable length at the same time, the two signals will collide and
• be destroyed and then must be retransmitted.
• For this reason, at each end of the cable there is a terminator.
• The terminator is designed to absorb the signal when the signal reaches the end, preventing signal bounce.
• If there is no termination, the entire network fails because of signal bounce, which also means that if there is ever
• a break in the cable, you will have unterminated ends and the entire network will go down

• Advantages of a Bus Topology

·         One advantage of a bus topology is cost

·         A bus topology uses less cable than a star topology or a mesh topology.

·         and you do not need to purchase any additional devices such as hubs.

·         Another advantage of a bus topology is the ease of installation.

·         With a bus topology, you simply connect the workstation to the cable segment or backbone

• Disadvantages of a Bus Topology

·         The main disadvantage of a bus topology is the difficulty of troubleshooting it.

Star Topologies

• In a star topology, all computers are connected through one central device known as a hub or a switch, as illustrated in below Figure . Each workstation has a cable that goes from the network card to the hub device.
• One of the major benefits of a star topology is that a break in the cable causes only the workstation that is connected to the cable to go down, not the entire network, as with a bus topology. Star topologies are very popular topologies in today’s networking environment

• Advantages of a Star Topology

·         One advantage of a star topology is scalability and ease of adding another system to the network.

·         If you need to add another workstation to the network with a star topology, you simply connect that system to an unused port on the hub.

• Disadvantages of a Star Topology

·         if the hub fails in a star topology, the entire network comes down, so we still have a central point of failure. But this is a much easier problem to troubleshoot than trying to find a cable break with a bus topology.

·         Another disadvantage of a star topology is cost. To connect each workstation to the network, you will need to ensure that there is a hub with an available port, and you will need to ensure you have a cable to go from the workstation to the hub. Today, the cost is increasingly less of a disadvantage because of the low prices of devices such as hubs and switches

Mesh Topologies

• A mesh topology is not very common in computer networking today,
• In a mesh topology, every workstation has a connection to every other component of the network,