TOPOLOGIES OF COMMUNICATING MACHINES

TYPES OF NETWORK TOPOLOGY

NETWORK TOPOLOGY IS THE SCHEMATIC DESCRIPTION OF NETWORK ARRANGEMENT, CONNECTING VARIOUS NODES (SENDER AND RECEIVER) THROUGH LINES OF CONNECTION.

 

BUS TOPOLOGY

BUS TOPOLOGY IS A NETWORK TYPE IN WHICH EVERY COMPUTER AND NETWORK DEVICE IS CONNECTED TO A SINGLE CABLE.  WHEN IT HAS EXACTLY TWO END POINTS, THEN IT IS CALLED LINEAR BUS TOPOLOGY.

 

FEATURE OF BUS TOPOLOGY

1.       IT TRANSMITS DATA ONLY IN ONE DIRECTION

2.       EVERY DEVICE IS CONNECTED TO A SINGLE CABLE.

 

ADVANTAGES OF BUS TOPOLOGY

1.       IT IS COST EFFECTIVE CABLE REQUIRED IS LEAST COMPARED TO OTHER NETWORK TOPOLOGY.

2.       USED IN SMALL NETWORKS

3.       IT IS EASY TO UNDERSTAND

4.       EASY TO EXPAND JOINING TWO CABLES TOGETHER.

 

DISADVANTAGES OF BUS TOPOLOGY

1.       CABLE FAILS THEN WHOLE NETWORK FAILS.

2.       IF A NETWORK TRAFFIC IS HEAVY OR NODES ARE MORE THE PERFORMANCE OF THE NETWORK DECREASES.

3.       CABLE HAS LIMITED LENGTH

4.       IT IS SLOWER THAN RING TOPOLOGY.

 

 

RING TOPOLOGY

IT IS CALLED RING TOPOLOGY BECAUSE IT FORMS A RING AS EACH COMPUTER IS CONNECTED TO ANOTHER COMPUTER, WITH THE LAST ONE CONNECTED TO THE FIRST.  EXACTLY TWO NEIGHBOR FOR EACH DEVICE.

 

FEATURE OF RING TOPOLOGY

1.       A NUMBER OF REPEATERS ARE USED FOR RING TOPOLOGY WITH LARGE NUMBER OF NODES, BECAUSE OF SOMEONE WANTS TO SEND SOME DATA TO THE LAST NODE IN THE RING TOPOLOGY WITH 100 NODES THEN THE DATA WILL PASS THROUGH 99 NODES T EACH THE 100^TH NODE.  HENCE TO PREVENT DATA LOSS REPEATERS ARE USED IN THE NETWORK.

2.       THE TRANSMISSION IS UNIDIRECTIONAL BUT IT CAN BE MADE BIDIRECTIONAL BY HAVING TWO CONNECTORS BETWEEN EACH NETWORK NODE.  IT IS CALLED DUAL RING TOPOLOGY.

3.       IN DUAL RING TOPOLOGY, TWO RING NETWORKS ARE FORMED AND DATA FLOW IS OPPOSITE DIRECTION IN THEM.  ALSO IF ONE RING FAILS THE SECOND RING ACTS AS BACKUP TO KEEP THE NETWORK UP.

4.       DATA IS TRANSFERRED IN SEQUENTIAL MANNER I.E. BIT BY BIT.  DATA TRANSMITTED HAS TO PASS THROUGH EACH NODE OF THE NETWORK TILL THE DESTINATION NODE.

 

ADVANTAGES OF RING TOPOLOGY

 

1.       TRANSMITTING NETWORK IS NOT AFFECTED BY HIGH TRAFFIC OR BY ADDING MORE NODES AS THE ONLY NODES HAVE TOKEN CAN TRANSMIT DATA.

2.       CHEAP TO INSTALL AND EXPAND

 

DISADVANTAGES OF RING TOPOLOGY

 

1.       TROUBLESHOOTING IS DIFFICULT IN RING TOPOLOGY.

2.       ADDING OR DELETING THE COMPUTERS DISTURB THE NETWORKING ACTIVITIES.

3.       FAILURE OF ONE COMPUTER DISTURBS THE WHILE NETWORK.

 

 

STAR TOPOLOGY

IN THIS TYPE OF TOPOLOGY ALL THE COMPUTERS ARE CONNECTED TO A SINGLE HUB THROUGH A CABLE. THIS HUB IS THE CENTRAL NODE AND ALL OTHER NODES ARE CONNECTED TO A CENTRAL NODE.

 

FEATURES OF STAR TOPOLOGY

 

1.       EVERY NODE HAS ITS OWN DEDICATED CONNECTION TO THE HUB.

2.       HUB ACTS AS A REPEATER FOR DATA FLOW.

3.       CAN BE USED WITH TWISTED PAIR, OPTICAL FIBER OR COAXIAL CABLE.

 

ADVANTAGES OF STAR TOPOLOGY

 

1.       FAST PERFORMANCE WITH FEW NODES AND  LOW NETWORK TRAFFIC.

2.       HUB CAN BE UPGRADED EASILY.

3.       EASY TO TROUBLESHOOT.

4.       EASY TO SETUP AND MODIFY.

5.       ONLY THAT NODE IS AFFECTED WHICH HAS FAILED, REST OF THE NODES CAN WORK SMOOTHLY.

 

DISADVANTAGES OF STAR TOPOLOGY

 

1.       COST OF INSTALLATION IS HIGH

2.       EXPENSIVE TO USE

3.       IF THE HUB FAILS THEN WHOLE NETWORK IS STOPPED BECAUSE ALL THE NODES UPON THE HUB.

4.       PERFORMANCE IS BASED ON THE HUB I.E. IT DEPENDS ON ITS CAPACITY.

 

 

MESH TOPOLOGY

 

IT IS POINT TO POINT CONNECTION TO OTHER NODES OR DEVICES.  ALL THE NETWORK NODES ARE CONNECTED TO EACH OTHER.  MESH HAS  (n(n-1))/2 PHYSICAL CHANNELS TO LINK N DEVICES.  THERE ARE TWO TECHNIQUES TO TRANSMIT DATA OVER THE MESH TOPOLOGY.

 

THEY ARE

1.       ROUTING

2.       FLOODING

 

MESH TOPOLOGY ROUTING

 

IN ROUTING, THE NODES HAVE A ROUTING LOGIC, AS PER THE NETWORK REQUIREMENTS.  THE ROUTING LOGIC TO DIRECT THE DATA TO REACH THE DESTINATION USING THE SHORTEST DISTANCE.  OR ROUTING LOGIC WHICH HAS INFORMATION ABOUT THE BROKEN LINKS, AND IT AVOIDS THOSE LINKS., AND IT AVOIDS THOSE NODES.

WE CAN HAVE ROUTING LOGIC, TO RECONFIGURE THE FAILED NODES.

 

MESH TOPOLOGY FLOODING

 

IN FLOODING, THE SAME DATA IS TRANSMITTED TO ALL NETWORK NODES, HENCE NO ROUTING LOGIC IS REQUIRED.   THE NETWORK IS ROBUST AND IT IS VERY UNLIKELY TO LOOSE THE DATA. BUT IT LEADS UNWANTED LOAD OVER THE NETWORK.

 

TYPES OF MESH TOPOLOGY

 

PARTIAL MESH TOPOLOGY

IN THIS TOPOLOGY SOME OF HE SYSTEMS ARE CONNECTED IN SOME FASHION AS ESH TOPOLOGY BUT SOME DEVICES ARE ONLY ONNECTED TO TWO OR THREE DEVICES.

 

FULL MESH TOPOLOGY

EACH AND EVERY NODES ARE CONNECTED TO EACH OTHER.

 

FEATURES OF MESH TOPOLOGY

 

1.       FULLY CONNECTED

2.       ROBUST

3.       NOT FLEXIBLE

 

 

ADVANTAGES OF MESH TOPOLOGY

 

1.       EACH CONNECTION CAN CARRY ITS OWN DATA LOAD.

2.       IT IS ROBUST

3.       FAULT IS DIAGNOSED EASILY

4.       PROVIDES SECURITY AND PRIVACY

 

DISADVANTAGES OF MESH TOPOLOGY

 

1.       INSTALLATION AND CONFIGURATION IS DIFFICULT

2.       CABLING COST IS MORE

3.       BULK WIRING IS REQUIRE

 

TREE TOPOLOGY

 

IT HAS ROOT NODE AND ALL OTHER NODES ARE CONNECTED TO IT FORMING HIERARCHY  IT IS ALSO CALLED HIERARCHICAL TOPOLOGY.  IT SHOULD AT LEAST THREE LEVELS TO THE HIERARCHY.

 

FEATURES OF TREE TOPOLOGY

 

1.       IDEAL IF WORKSTATION ARE ARRANGED IN GROUP

2.       USED IN WIDE AREA NETWORK.

 

 

ADVANTAGES OF TREE TOPOLOGY

 

1.       EXTENSION OF BUS AND STAR TOPOLOGY

2.       EXPANSION OF NODES IS POSSIBLE AND EASY

3.       EASILY MANAGED AND MAINTAINED

4.       ERROR DETECTION IS EASILY DONE

 

DISADVANTAGES OF TREE TOPOLOGY

 

1.       HEAVILY CABLED

2.       COSTLY

3.       IF MORE NODES ADDED MAINTENANCE IS DIFFICULT

4.       CONTROL HUB FAILS NETWORK FAILS