How To Design a Local Area Network (LAN Topologies)

To design any network layout, it is important to know the basic LAN topologies and to consider their advantages and disadvantages. There are basically three topologies, and you can choose according to your need.

Bus Topology: This is a very simple way of connecting computers. In this type of layout, all computers are hooked on a single transmission medium, usually a coaxial wire, using T-connectors. A terminator is also placed at the wire's end in order to absorb free signals so that the computers can send data.

Advantages:

• Simple installation.
• Economical use of cable.
• Media is inexpensive and easy to work with.
• Simple and reliable.
• Easy to extend

Disadvantages:

• Can slow down in heavy traffic.
• Difficult to troubleshoot.
• Cable break can affect many users.
• High EMI (electromagnetic interference).

Star Topology:

In this topology, computers are connected by cable segments to a centralized component called a hub. Signals are transmitted from the sending computer through the hub to all computers on the network.

Advantages:

• Low EMI.
• Easy to troubleshoot.
• Easy to modify and add new computers.
• Centralized management.
• Failure of one computer does not affect the rest of the network.

Disadvantages:

• If the hub fails, then the whole network breaks down.

Ring topology: The ring topology connects computers on a single circle of cable. There are no terminated ends. The signals travel around the loop in one direction and pass through each computer. Each computer acts like a repeater to boost the signal and send it on the next computer.

Advantages

• Equal access for all computers.
• Even performance despite many users.
• High speed.
• Low EMI.

Disadvantages

• Failure of one computer can impact the rest of the network.
• Problems hard to isolate.
• Network reconfiguration disrupts operation.

These were the basic topologies for designing any local area network. You may choose any according to the size and the need of your network.

The basic steps are:

1. Draw a rough sketch of your network (where the computer will be, main switch, etc.)
2. Consider all the topologies carefully.
3. Choose the one that suits most of your requirements.
4. For wires, the most suitable are:
   • Coaxial for bus topology.
   • UTP for star topology.
   • STP for ring topology.
5. Install. However, it would be safer that you employ technicians for the job.
6. Check the network.

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