NETWORK TOPOLOGY

Network topology also called network structures. It is the study of the arrangement or mapping of the elements (links,nodes) of a network, especially the physical and logical level.  The four main type of network topology are bus, star, ring and hybrid. 

A PHYSICAL TOPOLOGY

It is any given node in the LAN will have one or more links. There are some examples of physical topology:

• Ethernet 
• Local Talk

A LOGICAL TOPOLOGY

The mapping of the data flow of the data between the nodes in the network determines the logical topology of the network.

Linear Bus

A linear bus topology consists of a main run of cable with a terminator at each end and continuous length of cable that connects two or more devise together. A linear bus also called a backbone network. Only one computer can transfer information at a time. When a computers sends information, the information move s through the entire length of the cable. The destination computer must retrieve the information from the cable.

• ADVANTAGE

1. Easy to connect a computer or peripheral to a linear bus
2. Requires less cable length than a star topology.
3. Often used to connect a few computers located in a small area.

• DISADVANTAGE

1. Terminators are required at both ends of the backbone
2. A faulty cable or workstation will take the entire LAN.
3. The other computers on the network cannot exchange information while the cable is broken.

STAR TOPOLOGY

Is designed with each node (file server,workstation) connected directly to a central network HUB or concentrator. Data on a star topology passes through the HUB before continuing to its destination. The HUB manages and controls all function of the network.

• ADVANTAGE

1. Easy to install and wire
2. Easy to add new workstations
3. Centralized control

• DISADVANTAGE

1. Requires more cable length than a linear topology
2. If the HUB fails ,nodes attached are disabled
3. Large amount of cable are also used in star topology.

RING TOPOLOGY

A ring topology consists of individual computers connected to a single length of cable arranged in a ring. The information on the ring network travels in one direction only. When computers transfer information it send the information to the computer lactated next to it.

• ADVANTAGE

1. Great for small networks as it easy to install and the cost is usually low.
2. The Media Access Unit (MAU) can also be used to help prevent network shutdown.
3. A break in rings occurs, all computer before break will be able to exchange information.

• DISADVANTAGE

1. Expending a ring network may be difficult that expanding other type of networks.
2. Ring networks can be slightly more expensive to set up the other types pf networks.

HYBRID NETWORK TOPOLOGY

A network structures used a mixture of many different kings of network structures. A hybrid network structures such as ring, star. and bus network in one large network. The bus, ring, star and hybrid, structures all can be used with a centralization network layout.

LAST BUT NOT LEAST :

1. NIC is a network interface controller (also known as a network interface card, network adapter, LAN adapter and by similar terms) is a computer hardware component that connects a computer to a computer network.
2. NOS is a networking operating system (NOS) the software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions.
3. An Ethernet hub or concentrator is a device for connecting multiple twisted pair or fibre optic Ethernetdevices together, making them act as a single segment.
4. LocalTalk is a particular implementation of the physical layer of the AppleTalk networking system from Apple Computer. LocalTalk specifies a system of shielded twisted pair cabling, plugged into self-terminating transceivers.
5. A gateway is a node that allows you to gain entrance into a network and vice versa. On the Internet the node which is the stopping point can be a gateway or a host node. A computer that controls the traffic your network or your ISP (Internet Service Provider) receives is a node. In most homes a gateway is the device provided by the Internet Service Provider that connects users to the internet.
6. In a telecommunications network, a switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination.
7. A repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.