Network Topology

10th Sept 2013

Network Topology

-Refers to the layout of the computers and devices in a communication network.

-Refers to the both the phycsical and logical layout of the network.

Layout of the Network

Physical Topology- arrangement of a cabling

Logical Topology - the path that data travels between computers on a network is the logical

                                 topology

Types of network topology

Three commonly used network topologies are :

• BUS NETWORK TOPOLOGY

          -Consists of a single central cable(backbone) to which all computers and other devices 

            connect

          -Each devices is connected to the single bus cable through T-connector.

          -Terminator is required at each end of the bus cable to prevent the signal from bouncing

            back and forth on the bus cable

      

#Bus Network Topology

• Advantages

         -Inexpensive

         -Easy to install

         -Computers can be attached and detached at any point on the bus without disturbing the

           rest of the network

         -Failure of one device usually does not affect the rest of the bus network

• Disadvantages

        - Distruption occurs when computer or other devices are added or removed

        -A break in the cable will prevent all systems from accessing the network

        -Difficult to identify the problem if the entire network shut down

• STAR NETWORK TOPOLOGY

        -All the computers and other devices on the network connect to a central device thus 

         forming a star.

        -Two types of devices that provide a common central connection point to all the other  

         devices on the network are a hub and switch
        

#Star network topology

• Advantages

         -If one device fail,only that device is affected

         -Devices can be added to or removed from network with little or no distruption

         -Easy to troubleshoot and isolate

• Disadvantages

        -If the hub or switch fails,the entire network will be inorporabled.

        -Requires more cable than most of the other topologies

        -More expensive because of the cost of the hub/switch.

• RING NETWORK TOPOLOGY

       - A cable forms a closed loop(ring) with all computers and devices arranged along the ring

       -Data transmitted on a ring network travels from device to device around the entire ring, in           one direction (clockwise or counterclockwise).

       -Token passing is one method for sending data around a ring.

       -Each device takes turn sending and receiving information through the use of a token.

       

#ring network topology

• Advantages

         -The transmission of data is relatively simple as packets travel one direction only.

         -Cable faults are easily located,making troubleshooting easier

         -The uses of token passing enables all devices in a ring topology to share the network 

          recources faulty

• Disadvantages

         -A Failure in any cable or device breaks the loop and can take down the entire network

         -Data packets must pass through every computer thus make it slower

         -More difficult to install than a bus network.