Network Topology

NETWORK TOPOLOGY
-a network topology refers to the layout of the computers and devices in a communications network.
-it refers to both the physical topology and logical topology layout of a network.

Physical Topology
-the physical layout of nodes,workstations and cables in the network.

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

Type of network topology
-BUS NETWORK TOPOLOGY
-STAR NETWORK TOPOLOGY
-RING NETWORK TOPOLOGY

1.BUS NETWORK TOPOLOGY

-a bus network consists of a single central cable (backbone), to which all computers and other devices connect.

-when sending device transmits data, the address of the receiving device is inclided with thye transmission.if the devices address does not match the intended address for the data, the device ignores the data.if the data does not match the device address,the data is accepted.
-all devices receive the data but only the receiving device accept them.

Advantages and Disadvantages of bus network topology

Advantages
-inexpensive and easy to install
-computers and other nodes can be attached and  detached at any
 point on the bus without disturbing the rest of network.
-failure of one node usually does not affect the rest of the bus network.

Disadvantages
-because all systems on the network connect to a single cable or backbone,
 a break in the cable will prevent all systems from accessing the network.
-it is difficult to identify the problem if the entire network shut down.

2.STAR NETWORK TOPOLOGY

-all the computers and devices (nodes) on the network connect to a central device,
 thus forming a star.

Advantages and Disadvantages of star network topology

Advantages
-if one nodes fails, only that node is affected
-nodes can be added to or removed from network with little or no disruption.
-easy to troubleshoot and isolate problem

Disadvantages
-if the hub or switch fails, the entire network will be inoperable
-requires more cable than most of the other topologies
-more expensive because of the cost of the hub/switch

3. RING NETWORK TOPOLOGY

- On a ring network, a cable forms a closed forms a closed loop (ring) with all computers and devices arranged along the ring.

Advantages and Disadvantages of ring network topology

Advantages

-Transmission of data is simple as packets travel in one direction only.

-cable faults are easily located, making troubleshooting easier

-all nodes in ring topology share the network resources fairly

Disadvantages

-a failure in any cable or nodes breaks the loop and can take down entire network

-data packets must pass through every computer, thus make it slower

-more difficult to install than a bus network

Differentiate between LAN, MAN, and WAN

BASIS OF COMPARISON	LAN	MAN	WAN
Expands to	Local Area Network	Metropolitan Area Network	Wide Area Network
Meaning	A network that connects a group of computers in a small geographical area.	It covers relatively large region such as cities, towns.	It spans large locality and connects countries together. Example Internet.
Ownership of Network	Private	Private or Public	Private or Public
Design and maintenance	Easy	Difficult	Difficult
Propagation Delay	Short	Moderate	Long
Speed	High	Moderate	Low
Fault Tolerance	More Tolerant	Less Tolerant	Less Tolerant
Congestion	Less	More	More
Used for	College, School, Hospital.	Small towns, City.	Country/Continent.