Topology is refers to the way a network is laid out m either physically or logically. It uses common components of computer network to make a topology.
Topologies used in computer network with advantage and disadvantage
The Topologies are as follows :
Every device have a dedicated point to point link to every other device. A fully connected mesh network has n(n-1)/2 physical channels to link n devices.
Dedicated links means it carries traffic only between the two devices it connects.
2. Star Topology:
Advantages : a. Traffic is less
b. network failure is less i.e it is robust
c. Fault identification and Fault isolation is easy.
d. It enforces privacy and security.
Disadvantage: a. Cost is high.
b. Bulk of wires is used making space problem.
c. I/O ports required are large.
In star topology, each device has a dedicated point to point link only to a central controller called the hub. If one device wants to send data to another, it sends the data first to the hub which then relays it to the other device connected to it.
Advantages: a. Less cabling is required.
b. Easy to add or remove devices as it involves only one connections between a device and hub.
c. Each device needs only one link and one I/O port to connect it to any number of others.
d. It is robust, i.e if one link fails only that link is affected other links remain active.
Disadvantage: a. It is totally dependent on hub. i.e if hubs fails then the whole system will goes down.
A tree topology is a variation of a star. Nodes in tree are linked to the central hub as is done in star but every device connect to a secondary hub that in turn is connected to the central hub as shown.
Advantage: a. Allows more devices to be attached to a single central hub and can increase the distance a signal can travel between devices.
b. it allows the network to isolate and prioritize communication from different computers.
c. Less cabling is required.
d.It is robust, i.e if one link fails only that link is affected other links remain active.
Disadvantage: It is totally dependent on hub. i.e if hubs fails then the whole system will goes down.
A bus topology describes a multipoint configuration. One long cable acts as a backbone to link all the devices in the network. Nodes are connected to the bus cable by drop lines and taps as shown.
Advantages: a. Ease of installation.
b. bus uses less cabling then mesh, star or tree.
Disadvantage: a. Difficult to add new devices.
b. Fault isolation and identification is not easy.
c. Slow and signal quality degrades.
d. Less Secure,
5. Ring Topology:
In ring topology the devices used has a dedicated point to point line configuration only with the two devices on either side of it. A signal is passed along the ring in one direction, from device to device, until it reaches its destination. Each device has a repeater which regenerates the bits and passes them along to another device.
Advantage: a. Easy to install and reconfigure.
b. Fault isolation is simplified.
c. Easy to install and delete the devices as it requires to move only two connection.
Disadvantage: A break in the ring can disable the entire network as signal is unidirectional.
The above listed are some common topology, which every network engineer should know. Do comment below if you want to discuss on same topic or if you want to share more knowledge on the same Topology.