[NETWORK ACHITECTURE]  [NETWORK TOPOLOGY]  [CLASSIFICATION OF NETWORK]  [INTERNET]  [INTERNET SERVICES]
NETWORK TOPOLOGY
A network topology refers to
1) The layout of the computers and devices in a communications network or
2) The configuration of a network that consists of cables, computers, and other peripherals.

  It describes the physical and logical layout of the network.
What is a physical topology?
The physical topology of a network refers to the configuration of cables, computers, and other peripherals.


What is a logical topology?
The logical topology of a network refers to the architecture, that is the way in which the network appears to the devices that use it.

Node – any device that is connected to a network.
Client – a node that requests and uses resources available from other nodes.
Server – A nodes that share resources with other nodes.
Host – Any computer that provides services and connection to other computers on a network.
Switch – central node that coordinate the flow of data by sending messages directly between sender and receiver nodes.
Hub – The device that provides a common central connection point for nodes on network.
Network interface cards (NIC) – expansion cards located within  the system unit that connect a computer to a network.

TYPES	BUS NETWORK TOPOLOGY	RING NETWORK TOPOLOGY	STAR NETWORK TOPOLOGY
EXPLAINATION(PHYSICAL)	A bus network topology consist of a single central cable(backbone/trunk) to which all computers and other devices connect(node)	On a ring network topology a cable form a closed loop(ring) with all computers and devices arranged along the ring	All computers and devices on the network connect to a central device(hub/switch) thus forming a star
EXPAINATION(LOGICAL)	Send data in a series of signal in both direction in which all node will receive the message but the intended receipient will accept and the rest will reject	Data,instruction and information in ring topology travel as a packet in one direction(clockwise/anticlockwise)to all nodes using token until it reach to the destination	Data,information and instruction travel in star network topology through hub/switch,if the network use hub the device will send the message to all receipient but only the intended receipient will accept,if use switch it only send data to the intended receipient only
ADVANTAGES	Bus network topology are inexpensive and easy to install	Cable fault are easily located,making troubleshooting easier	If one device fails,only that device is affected
DISADVANTAGES	If the cable breakdown it will effect the entire network	A failure in any cable or devices breaks the loop and can take down the entire network	More expensive because of the cost of the hub/switch
DIAGRAM