SSS 3 WEEK 4: NETWORKING

 

- DEFINITION OF A NETWORK 

A computer network is a collection of computers and devices interconnected by communication channels that facilitate communications among users and allow users to share resources.

- TYPES OF A NETWORK

 The three types of computer networks are

- Ethernet

- Token ring

- Arcnet

ARCNET is an acronym for Attached Resources Computer Networks which is a star LAN topology like structure network. Arcnet was developed by John Murphy at Data Point Corporation in 1976.

TOKEN RING local area network (LAN) is a ring like structured topology network.

ETHERNET is a bus topology LAN network system. Ethernet LANS use coaxial or twisted pair cables to connect computer systems.

- NETWORK TOPOLOGY

• In computer networking, TOPOLOGY refers to the layout of connected devices. There are two types of network topology, a physical topology and a logical topology.

• The physical topology refers to layout of cables and network devices; and logical topology refers to the method of communication of the network devices.

- Network topologies are categorized into the following basic types;

- Star topology

- Bus topology

- Ring topology

Star topology: in a star topology network, the network devices are connected to a central point like a star. The central point maybe a Hub, a switch or a Router. All the individual network devices communicate with the central point. Thus when the hub fails the whole network is grounded but if other network device fails, the network will still be operating without the failed device. Also the star topology requires more cables because cables are laid from all the network devices to the hub.

Bus Topology: a bus network is connected together using a common backbone (A cable) to connect all devices together. The backbone is a shared communication medium that all devices are attached to or connected. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message. Bus works best with a limited number of devices but if the back bone cable fails, the entire network fails.

Ring Topology: in a ring topology all the devices are connected together in a ring form. That is every device has two neighbours for communication purposes.

NETWORK DEVICES

The network devices are the nodes of the networks. They are devices that aid connection and communication. The common network devices are:

- Hub

- The Network Interface Card (NIC)

- The Switch

- The Router

- The Modem

HUB: a Hub is a device that connects all other device in a star topology network together. Every other device connects to the Hub through a single cable.

MODEMS: modem is an acronym for MOdulator/DEModulator, it’s a device that converts digital data to analog data and vice versa.

SWITCHES: A switch is a device that channels incoming data from any network device to the specific device that is the destination of the data.

BRIDGE: a bridge is a device that connects two similar networks together. A bridge will connect and join two star networks together.

ROUTER: A router is a network device that connects two or more dissimilar networks together. E.g. a router can connect a star network together with a ring network; a wireless network and a cable network together, a LAN and a WAN and so on.

Network Interface Card (NIC)

A NIC also known as a Network adapter, LAN adapter, Network interface controller, is a computer hardware component that connects a computer to a network, it’s the card that possess a network port, where network connectors are plugged before the system can be on a network.

 BENEFITS OF NETWORKING 

- Some benefits of computer network are listed below:

- It helps to enhance connectivity

- Networking helps in sharing of hardware resources like a printer, scanner or even modem for internet connectivity.

- It eases management of data, where all data can be stored in a centralised place where all other users on the network can have access to the information on the network at the same time.

- Internet: it’s a network of networks that connects different people from part of the world together, called the Global Village; it allows people to share resources across the globe.

- Data sharing: sharing data through use of network helps saves a lot of time and energy. It also facilitates the use of applications like databases.

- Networking also promotes global games which users can connect as different usernames and play the same game using the same servers.

ASSIGNMENT

1. List 3 advantages and disadvantages of a Star network topology

2. List 2 advantages and disadvantages of a Bus network topology

3. What is the difference between a Bridge and Router

4. State the main difference between a Switch and a Hub.