1. Computer Networks Part 2
Topology

2. Network Topology

3. Network Topology Topology means “arrangement” or “layout”
How the different parts of a network are arranged and connected together.
Network Topologies:
Bus
Ring
Star
Mesh
Hybrid

4. Criteria for Topology Selection
Cost
Ease of maintenance
Ease of installation
Cable fault tolerance

5. Bus Topology
One single network cable is used from one end of the network to the other end.

6. Bus Topology Advantages Disadvantages Simple to install
Cheap to install
Less cable is used compare to any other topologies
Disadvantages
If main cable is damaged, the whole network will fail.
As more workstations are connected to the network, the network performance will become slower.
Every workstation can access all the data on the network (Security Issues)
Not flexible
Little fault tolerance
Hard to troubleshoot

7. Ring Topology
If we connect the two ends of bus topology cable, we have a ring topology
Each computer is connected to two other computers to form a ring

8. Ring Topology Data travels one way on the ring.
Each computer receives data in turn till it reaches the destination

9. Ring Topology Advantages Disadvantages Simple to design
Transfer data quickly (one way traffic)
Disadvantages
The whole network fails if:
the main cable fails
or if any device on the network fails

10. Star Topology A central point called hub hosts a set of workstations
Each device on the network has its own cable connecting to a central hub or switch.

11. Star Topology Advantages Disadvantages Can add nodes easily
Single failure cannot bring down the
network
Easy to troubleshoot
Disadvantages
Uses more cables which make it expensive
If hub fails, the entire system will fail

12. Mesh Topology All nodes are connected to each other
More popular in WAN than in LAN

13. Mesh Topology Advantages Disadvantages
The most reliable network topology
Disadvantages
Expensive as cable cost is high

14. Hybrid Topology
a network topology that combines two or more of the previous topologies.
E.g. combines several star networks

15. Activity

16. Test