Rahul Khadse
Topologies are the way of laying out the network .Topologies may be either both logical describe that how the cables are run into your network & logical topologies describe that how the network message will travel into your network.
There are different types of topologies are:-
1> BUS TOPOLOGIES: - A bus topology connects
each computer (nodes) to a single segment trunk (a communication line, typically coax cable
that is referred to as the 'bus'. The signal travels from one end of the bus to
the other. A terminator is required at each to absorb the signal so as it does
not reflect back across the bus. A media access method called CSMA/MA is used
to handle the collision that occurs when two signals placed on the wire at the
same time. The bus topology is passive. In other words, the computers on the
bus simply 'listen' for a signal; they are not responsible for moving the
signal along.
* Connecter used:-BNC (British Naval Connector) => The BNC connector is a type of RF connector used for terminating coaxial cable.
* Cable used: - Coaxial thin & thick type cable.
*Maximum length: - 1>with thin -> 185 meter ->30 device.
2>with thick-> 500 meter
-> 100 device.
*May be logical & physical
Advantages: * Failure of one of the station does not affect others.
1> Good compromise over the other two
topologies as it allows relatively high rate of data transition.
2> Well suited for temporary networks
that must be set up in a hurry.
3> Easy to implement and extend.
Disadvantage:
* Require a network to detect when
two nodes are transmitting at the same time.
1> Does not cope well with heavy
traffic rates
2> Difficult to
administer/troubleshoot.
3> Limited cable length and number of
stations.
4> A cable brake can disable the entire
network; no redundancy.
5> Maintenance cost may be higher in
the long run.
6> Performance degrade as additional
computers are added.
* Cable used: - STP (Shielded Twisted
Pair) / UTP (Unshielded
Twisted Pair)
* Central device: - Hub or Switch.
* Connecter used: - RJ45 (Register Jack)
* Maximum length: - 100 meter with proper Colum coding.
*If wire damage it will work only one computer will
not work.
* STP cable is very costly.
Media Access Method With ->
HUB -> CSMA/CD
-> SWITCH -> CSMA/CA
Speed With -> HUB -> 10mbps
-> SWITCH -> 100 mbps
3> MESH TOPOLOLY :- Each one is connected with each other called Mesh Topolopy.
* Each computer having three LAN card.
* Thick type: - 500 meter -> 100 network device.
* The arrangement of the network
nodes is such that it is possible to transmit data from one node to many other
nodes at the same time.
* Re Configuration is complicated and hard. (To done when one wire damage)
* Very costlier than star topologies.
4> RING TOPOLOGY: - Ring topology is a
computer network configuration where each network computer and device is
connected to each other forming a large circle (or similar shape). Each packet
is sent around the ring until it reaches its final destination. (Developed by
IBM in 1985)
Advantage
1> Easy to install & reconfigure.
2>Easy to add new node as only two connections need to be changed.
Disadvantage
1> A fault in the ring can disable the
entire network. This weakness can be resolved by using a dual ring.
2> Token may get lost, or many token are
generated.
Token ring -> Media access method .data will transfer
clockwise that's why it is called ring topology.
Duel ring topology -> Two token generate & very expensive.
5> HYBRID TOPOLOGY: - Communication of more than
one network topology called Hybrid Topology. A hybrid topology is always
produced when two different basic network topologies are connected.
Posted in: MCITP
