In computer networks, the term 'network topology' is used to explain the geometric arrangement of nodes and cables in a network and the logical flow of information within that network.
A node refers to any device or point in a network where data can be sent, received, or passed through.
Nodes can include computers, servers, routers, switches, hubs, printers, or any other device capable of sending or receiving data within a network.
Each node typically has a unique identifier, such as an IP address, and can communicate with other nodes in the network either directly or indirectly through various network devices and connections.
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Importance of Network Topology
Different Types of Network Topologies
There are several types of network topologies which can be configured in different ways to get different outcomes.
Some of the most common types of network topologies are as follows:
- Bus Topology
- Star Topology
- Ring Topology
- Mesh Topology
- Hybrid Topology
Let’s discuss all these devices in detail.
1. Bus Topology
In a bus topology, all devices are connected to a single backbone cable known as the bus. Devices communicate by sending data packets along the bus.
Each packet contains the address of the sender and the intended recipient. This process of transmitting data from one node/device to all other nodes/devices is called broadcasting.
In here, the data transmission over the network connections occurs in one direction.
Ethernet LAN is an example of bus topology.
Advantages:
- Simple and inexpensive to set up.
- Well-suited for small networks with limited devices.
- Failure of one node doesn't bring down the whole network.
Disadvantages:
- Limited scalability.
- Fault diagnosis is difficult.
- Susceptible to cable failures; if the main cable breaks, the entire network can go down.
2. Star Topology
In a star topology, each device is connected directly to a central hub or switch. All data traffic passes through the central hub, which manages communication between devices.
Star Topology is the most common network topology as they are easy to install, troubleshoot and maintain. They are more suitable for small businesses.
Advantages:
- Easy to install and maintain.
- More reliable; if one device fails, it doesn't affect the rest of the network.
Disadvantages:
- Requires more cable than a bus topology.
- Failure of the central hub can bring down the entire network.
3. Ring Topology
In a ring topology, each device is connected to two other devices, forming a closed loop or a ring. Data travels in one direction around the ring until it reaches its destination.
Advantages:
- Simple to install and expand.
- No signal amplification is required as each node amplifies the signal.
- No central hub, so failure of one device doesn't necessarily disrupt the entire network.
Disadvantages:
- Failure of one device or cable can disrupt the entire network.
- Addition of nodes to the network is difficult.
- Slower data transfer speeds compared to other topologies.
4. Mesh Topology
In a mesh topology, every device is connected to every other device in the network.
There are two types of mesh topologies:
- Full mesh: Every device is connected to every other device.
- Partial mesh: Only some devices are connected to every other device.
Advantages:
- Can handle high traffic volumes.
- Highly reliable; if one connection fails, there are alternative paths for data to travel.
Disadvantages:
- Requires a large amount of cabling.
- Expensive and complex to set up, especially for full mesh topologies.
5. Hybrid Topology
Advantages:
- Offers flexibility and scalability.
- Can be customized to meet specific network requirements.
Disadvantages:
- Can be complex to design and manage.
- Requires careful planning to ensure compatibility between different topology types.