The Basic Components of

Computer Network

Created by: Ghadeer H. AbosaeedJune 22, 2012

Learning

• Students will be able to a- Identify the basic components of any computer network. b. Explain the different purposes of network components.

Network Components

A network operation needs devices that are designed to handle certain network functions. The devices are often called networking devices or equipment and specifically referred to as Network Components.

Each network component has a name that is related to its functions.

A network component's functions are not necessarily handled by a specific device. Therefore, there are many products combine several networking components in a device.

The Main Components of any Computer Network

• The Main Components of any Computer Network are:

1. Network Adapter OR Network Interface Card (NIC).

2. Modem

3. Hubs and Repeaters

4. Bridges and Switches

5. Routers

Network Adapter OR

Network Interface Card (NIC) Network adapter works as an interface between a

computer or device and a network. Network adapter converts a computer message

into electrical or optical signals for transmission across the network.

Internal network adapter is installed inside a computer on an expansion slot.

External network adapter is a separate device that is connected to a computer via serial port, parallel port, and mostly USB port.

Network Interface Card (NIC)

Modem You must connect your computer to a modem or

install an internal modem inside your computer when you want to connect to the Internet.

The type of modem depends on the Internet access method that you choose.

You may need a voice band modem, a cable modem, an ADSL modem, or a GPRS modem.

Your modem will communicate with the corresponding modem at your ISP during an Internet connection, transmit your computer message to the ISP (upstream), and receive Internet content forwarded by the ISP (downstream).

Modem

Hubs

• Hub is the central connection point in a network.

• Hub is used in a network that uses star topology.

• A sending computer transmits its signal to a hub, the hub then retransmits the signal to all other computers.

• Using a hub, the network bandwidth (capacity) is shared by all available computers, therefore each computer only uses a portion of bandwidth.

Hubs

• Hub is mostly used in small networks where there are only a few connected devices or computers.

• However, hub is not required if there are only two computers in a network.

• In that case, a direct connection using cable or wireless link can be used to connect both computers.

Hubs

Repeaters

• A Repeater receives signal from a transmitter, amplifies it, and retransmits it to a receiver.

• Repeater is put in a network to extend the network to a longer distance or a greater area.

• There can be more than one repeater between a transmitter and a receiver, however the number of repeaters is not unlimited, because additional repeaters may introduce more interference or noise.

Repeaters

Bridges• Bridges operate at the data link layer of the

OSI model. • The function of the bridge is to make

intelligent decisions about whether or not to pass signals on to the next segment of a network.

• When a bridge sees a frame on the network, it looks at the destination MAC address and compares it to the forwarding table to determine whether to filter, flood, or copy the frame onto another segment.

Bridges

Switches• Like hub, switch works as the central

connection point in a network.• Switches learn certain information about the

data packets that they receive from computers on the network.

• They use this to build forwarding tables to determine the destination of data being sent by one computer to another on the network.

• They help segment a network and reduce network traffic congestion by limiting each port to its own collision domain.

Switches

Routers• Routers operate at the Network layer of the

OSI model. • They are slower than bridges and switches

but make "smart" decisions on how to route packets received on one port to a network on another port.

• Routers are capable of segmenting the network.

• Routers are capable of segmenting a network into multiple collision domains as well as into multiple broadcast domains.

Routers

• Routers can be computers with special network software installed on them or they can be other devices built by network equipment manufacturers.

• Routers contain tables of network addresses along with optimal destination routes to other networks.

Routers

Guide to Network Components,

http://freepctech.]com/pc/002/networks002.shtml