Transcript Network Components - Online Computer Networking Course

The Basic Components
of Computer Network
Created by: Ghadeer H. Abosaeed
June 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