Show understanding of the bus, star, mesh and hybrid topologies

2.1 Networks including the Internet

Objective: Show understanding of the bus, star, mesh and hybrid topologies.

Bus Topology 📡

Imagine a single bus line that all students ride on. Every computer is a stop on the same line, sharing the same cable.

In a bus topology, all nodes are connected to a single communication line.

• Pros: Simple, cheap to set up.
• Cons: One fault can bring down the whole network; limited cable length.

1. Install a single backbone cable.
2. Connect each node with a tap or split.
3. Ensure termination at both ends.

Number of connections: $N$ nodes share one cable.

Star Topology 🛠️

Think of a telephone exchange where every line connects to a central switch.

In a star topology, all nodes connect to a central hub or switch.

• Pros: Easy to add/remove nodes; failure of one cable does not affect others.
• Cons: Central hub is a single point of failure; more cable required.

1. Set up a central hub or switch.
2. Run individual cables from each node to the hub.
3. Configure the hub for the network.

Number of connections: $N$ cables to the hub.

Mesh Topology 🌐

Picture a city grid where every intersection has a road to every other intersection.

In a full mesh, every node has a direct link to every other node.

• Pros: High reliability; multiple paths.
• Cons: Expensive, complex cabling.

1. Determine the number of nodes $N$.
2. Install $N(N-1)/2$ cables.
3. Configure routing protocols.

Number of connections: $$\frac{N(N-1)}{2}$$.

Hybrid Topology 🔌

Imagine a city that uses both bus lines and roads, combining the best of each.

A hybrid topology mixes two or more topologies (e.g., star + bus).

• Pros: Flexible, can be tailored to needs.
• Cons: Can be complex to design.

1. Identify the parts of the network that benefit from each topology.
2. Design the layout combining them.
3. Implement with appropriate hardware.

Example: A university campus network often uses a star for the main campus and a bus for the dormitories.

Topologies Comparison 📊