Thursday, 5 October 2017

all about network topology you want to know!

Star topology

Devices and computers on a network connect to a central hub,(which may be a hub, a router or a switch).
Hub acts as a junction to connect different nodes present in Star Network, and at the same time it manages and controls whole of the network.

Advantages
  • Signals don’t necessarily get transmitted to all the workstations. A sent signal reaches the intended destination after passing through no more than 3-4 devices and 2-3 links.
  • Easy to connect new nodes or devices. In star topology new nodes can be added easily without affecting rest of the network. Similarly components can also be removed easily.
  • Centralised management. It helps in monitoring the network
  • Failure of one node or link doesn’t affect the rest of network. At the same time its easy to detect the failure and troubleshoot it.

Disadvantages
  • A major disadvantage of this network topology is that if the central hub fails, all computers connected to that hub would be disconnected. 
  • Dependent on a central hub rather than an individual and reliable network source.
  • The use of hub, a router or a switch as central device increases the overall cost of the network.
  • Performance and as well number of nodes which can be added in such topology is depended on capacity of central device.
  • More software is required to run the network efficiently.

Bus topology
All the nodes are connected to the single cable (called bus), by the help of interface connectors. This central cable is the backbone of the network and is known as Bus . Every workstation communicates with the other device through this Bus.

Advantages
  • Easy to implement and extend
  • Well suited for temporary networks (quick setup)
  • Initially less expensive than other topologies
  • The linear bus network is well-suited for LAN

Disadvantages
  • Difficult to administer/troubleshoot.
  • Limited cable length and number of stations.
  • If there is a problem with the cable, the entire network goes down.
  • Maintenance costs may be higher in the long run.
  • Performance degrades as additional computers are added or on heavy traffic.
  • Low security (all computers on the bus can see all data transmissions).
  • One virus in the network will affect all of them
  • Proper termination is required.(loop must be in closed path).
  • If one node fails, the whole network will shut down.
  • If many computers are attached, the amount of data flowing causes the network to slow down.

Hybrid topology
Tailor-made Integration of two or more different topologies to form a resultant topology.The network adopts the characteristics and functioning of the combined topologies,rather than just the one.

Advantages
  • Unlike other networks, fault detection and troubleshooting is easy in this type of topology. The part in which fault is detected can be isolated from the rest of network and required corrective measures can be taken, WITHOUT affecting the functioning of rest of the network.
  • Its easy to increase the size of network by adding new components, without disturbing existing architecture.
  • Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources. Special care can be given to nodes where traffic is high as well as where chances of fault are high.
  • Hybrid topology is the combination of two or more topologies, so we can design it in such a way that strengths of constituent topologies are maximised while there weaknesses are neutralised. For example we saw Ring Topology has good data reliability (achieved by use of tokens) and Star topology has high tolerance capability (as each node is not directly connected to other but through central device), so these two can be used effectively in hybrid star-ring topology.

Disadvantages
  • One of the biggest drawbacks of the hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient.
  • The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down.
  • As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.

Ring topology
A computer network configuration where each network computer and device are connected to each other forming a large circle.
Each packet is sent around the ring until it reaches its final destination. Today, the ring topology is seldom used. Below is a visual example of a simple computer setup on a network using a ring topology.

Advantages
  • Data is quickly transferred
  • The transmission of data is relatively simple as packets travel in one direction only.
  • Adding additional nodes has very little impact on bandwidth
  • It prevents network collisions because of the media access method or architecture required
Disadvantages
  • Data packets must pass through every computer between the sender and recipient therefore this makes it slower.
  • If any of the nodes fail then the ring is broken and data cannot be transmitted successfully.
  • It is difficult to troubleshoot the ring.
  • Because all stations are wired together, to add a station you must shut down the network temporarily.
  • In order for all computers to communicate with each other, all computers must be turned on.
  • Total dependence upon the one cable

Wireless network topology
Wireless networks use different technologies depending on the distance to achieve, the number of devices to connect, and the amount of information to transmit. The technologies include;
  • WPAN, WLAN, WMAN and WWAN

Advantages
  • Allows for wireless remote access
  • The network can be expanded without disruption to current users
  • WIFi access points are available in capacities supporting anywhere from 15 to as many as 254 users
  • Direct communication between devices
  • Support various devices such as mobile phones, laptops, tablets, PC’s etc.
  • Because Wi-Fi is a true standard, you can mix and match access point and wireless hardware to meet your desired price, performance, and feature requirements for your wireless network
  • the wireless nature of such networks allows users to access network resources from nearly any convenient location within their primary networking environment(a home or office).
  • Wireless networks have a variety of access points that can be found within private contained areas, or public environments.
Disadvantages
  • There are potential security issues associated with wireless transmissions
  • Limited speed in comparison to other topologies
  • Limited access range.While sufficient for a typical home, it will be insufficient in a larger structure. To obtain additional range, repeaters or additional access points will have to be purchased. Costs for these items can add up quickly.

Life Update

It has been awhile since i blog about anything!. hello hooomans! Life has been busy lately with a lot of assignments and test. My gosh i ho...