Subtopic 1

IMPORTANCE OF NETWORKS AND COMMUNICATIONS

Networking and communications technology is fast changing the way people view society and how we plan our daily social activities.

Through networking technology alone, many today are finding friends online, visiting a library in another country. Some people are able to go to the banks after they are closed, as well as getting the latest development in news from within and outside the country.

Mobile communications today is also based on the networking technology. Surfing the internet is not only limited to the desktop computer users but also those who have mobile phones with wireless technology. At present there are more than 7 million such users across the world.

In communications technology, you think of a bus as a common “highway” on which data is transmitted.

A bus refers to the main physical pathway or central cable where all other devices are connected to it. Like a major motor highway, all traffic flow will be affected if this main “road” is broken.

A bus topology consists of a single central cable to which all computers and

other devices connect. A bus topology is also known as a bus network.

DESCRIPTION OF BUS TOPOLOGY

Bus networks are very common in Local Area Networks (LAN). A bus network must have a common backbone (the central cable) to connect all devices.

All nodes share the backbone to communicate with each other on the

network. Sometimes, a bus network has more than one server. Sometimes, a server is not needed on the network.

 

 ADVANTAGES OF BUS TOPOLOGY

RING TOPOLOGY

A ring topology consists of all computers and other devices that are connected in a loop.Ring topology is also known as a ring network.

A ring network can be found in Local Area Networks. 

In a ring network each node directly connect to two neighbouring nodes.

A server may exist in a ring network, but it willnot connect to all the nodes in the network.

DISADVANTAGES OF BUS TOPOLOGY

• Easy implementation. New devices can be added to the backbone or to the existing nodes.
• Failure of a node doesn't affect the entire LAN.
• No disruptions to the network when connecting or removing devices.
• Network can easily be extended, by adding new devices to the backbone or existing nodes.

DEPENDENCE OF A BUS TOPOLOGY
If one of the nodes fails, the bus network would still function as long as the backbone is working. If the backbone fails, the network will fail to function.

The server, like other nodes, will only communicate

to its two neighbouring nodes.

DEPENDENCE OF A RING TOPOLOGY

 If one of the nodes fails, the network will fail to function.

 ADVANTAGES OF A RING TOPOLOGY

• If the backbone fails, the entire bus network will be affected.
• Network speed decreases when the number of nodes increases.
• Troubleshooting is difficult when one of the nodes fails.