Network Topologies

Sheryl May C. Jagonia

Define Network

Define Networking

Network Classifications

Different Network Devices

Learning Objective

Define Topology Identify Different Kinds of Network

Topology Discuss Bus Topology Discuss Star Topology Discuss Ring Topology Discuss Tree Topology Discuss Mesh Topology Enumerate advantages and

disadvantages of each kind of topology

Network Topologies

Topologies

Topologies are the architectural “drawings” that show the overall physical configuration for a given communications system.

A topology will indicate the access methods and will govern the rules that are used to design and implement the communication system.

Topologies represent the drawing of your network cable plant.

Network Topologies

Line Topology

Bus Topology

Star Topology

Ring Topology

Mesh Topology

Tree Topology

Fully Connected

Bus Topology

A bus is a single electrical circuit to which all devices in the network are connected (although the bus might be made up of many individual pieces of wire).

Bus Topology

Advantages: Simple ReliableCabling is inexpensive, easy to extendUses cable economicallyMore computer can be added without disruption.

Disadvantages: Heavy traffic can slow down networkAny cable that is broken or terminated can bring the network downCan be difficult to isolate problems

Star Topology

By far, the most common network topology is the star topology.In a star network, individual computers are connected to a central device, such as a hub or switch.

Star Topology

Advantages: Easy to add new computers or modify networkCentralization enhances network monitoringSingle computer failure does not affect the network

Disadvantages: If the central hub fails, network will failRequires more cable and intricate installationIt is more expensive as it uses the most cabling.

Ring TopologyA "pure" ring topology is a collection of separate point-to-point links, arranged to make a ring.Each node's network interface card (NIC) has one input and one output connection, so each node is connected to two links.

Ring Topology

Advantages:

All computers have equal access to the rest of the network.

Even with many users, network performance is steady.

Disadvantages:

A single computer failure can impact the network.

Isolating problems can be difficult.

Adding or removing computers can disrupt network operations.

Tree Topology Tree topologies integrate

multiple star topologies together onto a bus.

In its simplest form, only hub devices connect directly to the tree bus.

This bus/star hybrid approach supports future expandability of the network much better than a bus or a star alone.

Tree Topology

Advantages:

Central hub (repeater) increases the distance a signal can travel between devices.

Disadvantages:

More cabling is required in a tree than in other topologies (except mesh).Entire network collapse if central Hub fails.

Mesh Topology

It uses redundant links between devices.

A true mesh has a link between each device in the network.

Most are hybrid mesh networks which have some redundant links but not all.

Mesh Topology

Advantage:

Relatively easy to troubleshoot and are very fault tolerant.

Guaranteed communications channel capacity.

Relatively easy to troubleshoot.

Disadvantage:

Difficulty of installation and reconfiguration because of the quantity of links.

Cost of maintaining redundant link

Fully Connected

Also referred to as a fully mesh topology

Requires that all the terminals be connected to all the other terminals, as it's name implies.

Fully Connected

Advantages:

A fault in one terminal on the network will not effect the rest.

When network usage is high, data packets can be transmitted via different cables, thereby reducing network clogging.

Disadvantages:

A large amount of cabling is required.

Topology Summary

Topologies are the important part of the network design theory.

Similarly you should have the knowledge of each network device so that you can properly use them according to your network needs.

So the basic understanding of the network topologies and network devices is a must to build a good network.

Design Considerations

The best topology involves matching with the environment it is to be used in.

The physical arrangement of computers do not dictate the necessary topology