The explanation of Components of Computer Networks

1. Course Title
Computer Networks
Submitted By
Name: Joty Akhter
ID: 1834902551
Topic
Components of Computer Network

2. Computer Network Components
Computer networks components comprise both physical parts as well as the
software required for installing computer networks, both at organizations and at
home. The hardware components are the server, client, peer, transmission
medium, and connecting devices. The software components are operating
system and protocols.
The following figure shows a network along with its components −
Type of transmission medium
• Hardware Components
• Software Components
• Cables and Connectors

3. Hardware Components
• Servers –
Which serve us the data that is called Server. Servers are high-
configuration computers that manage the resources of the network. The
network operating system is typically installed in the server and so they
give user accesses to the network resources. Servers can be of various
kinds: file servers, database servers, print servers etc.
• Clients –
Clients are computers that request and receive service from the servers to
access and use the network resources.
• Peers –
Peers are computers that provide as well as receive services from other
peers in a workgroup network.
• Transmission Media –
Transmission media are the channels through which data is transferred
from one device to another in a network. Transmission media may be
guided media like coaxial cable, fiber optic cables etc; or maybe
unguided media like microwaves, infra-red waves etc.
• Connecting Devices –
Connecting devices act as middleware between networks or computers, by
binding the network media together. Some of the common connecting devices
are:
• NIC
• Router
• Bridge
• Hub
• Repeater
• Gateway
• Switch

4. NIC
o NIC stands for network interface card.
o NIC is a hardware component used to connect a computer with another
computer onto a network
o It can support a transfer rate of 10,100 to 1000 Mb/s.
o The MAC address or physical address is encoded on the network card
chip which is assigned by the IEEE to identify a network card uniquely.
The MAC address is stored in the PROM (Programmable read-only
memory).
There are two types of NIC:
1. Wired NIC
2. Wireless NIC
Wired NIC: The Wired NIC is present inside the motherboard. Cables and
connectors are used with wired NIC to transfer data.
Wireless NIC: The wireless NIC contains the antenna to obtain the connection
over the wireless network. For example, laptop computer contains the wireless
NIC.

5. Router
o A router is a hardware device which is used to connect a LAN with an
internet connection. It is used to receive, analyze and forward the
incoming packets to another network.
o A router works in a Layer 3 (Network layer) of the OSI Reference
model.
o A router forwards the packet based on the information available in the
routing table.
o It determines the best path from the available paths for the transmission
of the packet.
• Advantages of Router:
o Security: The information which is transmitted to the network will
traverse the entire cable, but the only specified device which has been
addressed can read the data.
o Reliability: If the server has stopped functioning, the network goes
down, but no other networks are affected that are served by the router.
o Performance: Router enhances the overall performance of the network.
Suppose there are 24 workstations in a network generates a same amount
of traffic. This increases the traffic load on the network. Router splits the
single network into two networks of 12 workstations each, reduces the
traffic load by half.
o Network range

6. Bridge
A Bridge is a kind of networking device that interconnects two or more
networks together by dividing LAN into different segments. For this purpose it
uses forwarding database or a bridge table. Unlike hubs, bridge does not simply
broadcast traffic it effectively manages and it broadcasts traffic to network
segments. Moreover it functions at data link layer of the OSI model.
• Advantages of Bridges
1. Network Extend-
Sometimes bridges act as repeaters to extend a network. Networks with
different architectures can be connected together using bridges.
2. Increased Bandwidth-
Few of the nodes present on a network share a separate collision domain. For
these individual nodes, bridges increases bandwidth.
3. High Reliability-
Overall the network reliability is basically high in a bridge which makes it
easier to maintain the network. And also network congestion can be reduced by
dividing LAN into small segments.
4. Frame Buffering-
Different segments uses different MAC protocols. As a result it creates frame
buffers. Therefore, bridges works to interconnect different segments.
5. Protocol Transparency-
Bridges generally functions at the MAC layer. This makes higher levels of
protocol transparent.
• Disadvantages of Bridges
1.Cost-
On average a bridge costs more than the hub and repeaters. That is the reason
why it is only preferred when there is LAN network traffic load. In other
situations of variable data load it is advisable to use either a hub or a repeater.

7. 2. Speed-
A bridge does more buffering of frames and introduce more relays. This makes
them slower compare to a repeater.
3. Network Performance-
Since bridges make extra processing by viewing all of the MAC addresses, they
can potentially downgrade network performance.
4. Broadcast Filtering -
Bridges cannot individually filter the broadcast traffic. They simply forward
broadcast packets.
5. Broadcast Storms-
Another downfall of simply forwarding broadcast traffic is that they can
situation known as broadcast storms. Broadcast storms are nothing but high
amount of broadcast traffic.

8. Hub
Hub is that the central point of networking device that connects multiple
hosting devices to one network. It allows data to urge transferred between
themselves by functioning as a multi-port repeater. For this purpose, it uses
either fibre optic cable or a twisted pair cable.
• Advantages of Hub :
• Connectivity –
The primary function of the hub is to permit clients to attach to a network in
order that they will share and have conversations. For this purpose, hubs use
network protocol analyzer.
• Performance –
Hub is understood for having very less number of performance impacts on
the network. This is often because it operates using a broadcast model
which rarely affects the network.
• Cost –
Comparing to switches, hubs are really inexpensive. Basically thanks to its
sort of simplicity. Therefore, they will assist you to save lots of money. And
also due to their products they are widely available within the market.
• Device Support –
Hubs can connect different types of media all at once with a central hub.
Albeit the media want to operate at different speeds they will be wont to
support them.
• Area Coverage –
Area coverage of a network is restricted to a certain distance. Hub extends
the space of the network such communication is formed easy.
• Disadvantages of Hub :
• Collision Domain –
The function of the collision domain and again transfer of packet does not
affect actually it increases more chances of collision in between domains.
• Full-Duplex Mode –
Hubs cannot communicate fully duplex mode, it can only operate in half-
duplex mode. Half-duplex mode, in essence, means data are often

9. transmitted just one occasion at a given time. Therefore, the hub must
constantly switch its modes.
• Specification –
Hubs cannot support networks that are large like a token ring. This is often
because hubs must
share data among all the devices within the network.
• Network Traffic –
As the attachment was received in the packet so it cannot reduce traffic.
Hence, hubs make a high level of network traffic.
• Bandwidth Wastage –
Hubs cannot provide dedicated bandwidth for every device, it is to share
them. When sending large pieces of information all the bandwidths are
going to be occupied by the two computers leaving other computers with
slow network.

10. Repeater:
Repeaters are network devices operating at physical layer of the OSI model that
amplify or regenerate an incoming signal before retransmitting it. They are
incorporated in networks to expand its coverage area. They are also known as
signal boosters.
• Advantages of Repeaters
• Repeaters are simple to install and can easily extend the length or the
coverage area of networks.
• They are cost effective.
• Repeaters don’t require any processing overhead. The only time they
need to be investigated is in case of degradation of performance.
• They can connect signals using different types of cables.
• Disadvantages of Repeaters
• Repeaters cannot connect dissimilar networks.
• They cannot differentiate between actual signal and noise.
• They cannot reduce network traffic or congestion.
• Most networks have limitations upon the number of repeaters that can be
deployed.
•

11. Gateways
Gateway is a network connecting device that can be used to connect two
devices in two different networks implementing different networking protocols
and overall network architecture. In other words, a gateway is a node on a
network that serves as an entrance to another network.
A Gateway is also called as 'Protocol Converter' because it can convert the
data packets as per the destination network protocol requirement.
• Advantages of Gateway:
1. It can connect the devices of two different networks having dissimilar
structures.
2. It is an intelligent device with filtering capabilities.
3. It has control over both collisions as well as a broadcast domain.
4. It uses a full-duplex mode of communication.
5. It has the fastest data transmission speed amongst all network
connecting devices.
6. It can perform data translation and protocol conversion of the data
packet as per the destination network's need.
7. It can encapsulate and decapsulate the data packets.
8. It has improved security than any other network connecting device.
• Disadvantages of using a Gateway:
1. It is complex to design and implement.
2. The implementation cost is very high.
3. It requires a special system administration configuration.
4.
5.

12. Switch
A switch is a hardware device that connects multiple devices on a computer
network. A Switch contains more advanced features than Hub. The Switch
contains the updated table that decides where the data is transmitted or not.
Switch delivers the message to the correct destination based on the physical
address present in the incoming message. A Switch does not broadcast the
message to the entire network like the Hub. It determines the device to whom
the message is to be transmitted. Therefore, we can say that switch provides a
direct connection between the source and destination. It increases the speed of
the network.
• Advantages of Switches :
1. Increases Capacity –
They increment the accessible data transfer capacity of the organization.
2. Reduces Burden –
They help in lessening the outstanding burden on individual host PCs.
3. Increment Presentation –
They increment the presentation of the organization.
4. Less casing Impacts –
Networks that use switches will have fewer casing impacts. This is because
of the way that switches make impact areas for every association.
5. Straightforward –
Switches can be associated straightforwardly with workstations.
6. Increases Bandwidth –
It increases the available bandwidth of the network.
7. Less frame collisions –
Networks that use switches will have fewer frame collisions
8. More secure –
Since the switch is isolated, data will go only to the destination.
• Disadvantages of Switch :

13. 1. Costly –
They are more costly in contrast with network spans.
2. Tough Availability issues –
Network availability issues are hard to be followed through the organization
switch.
3. Issues in traffic broadcasting –
Broadcast traffic might be problematic.
4. Defenseless –
If switches are in the indiscriminate mode, they are defenseless against
security assaults for example caricaturing IP address or catching Ethernet
outlines.
5. Need for Proper Planning –
Proper planning and arrangement are required to deal with multicast
parcels.
6. Mechanical Component can wear out –
The switch’s mechanical component can wear out with time.
7. Physical contact is mandatory –
Must have physical contact with the object to be actuated.

14. Modem
o A modem is a hardware device that allows the computer to connect to the
internet over the existing telephone line.
o A modem is not integrated with the motherboard rather than it is installed
on the PCI slot found on the motherboard.
o It stands for Modulator/Demodulator. It converts the digital data into an
analog signal over the telephone lines.
Based on the differences in speed and transmission rate, a modem can be
classified in the following categories:
o Standard PC modem or Dial-up modem
o Cellular Modem
o Cable modem

15. Software Components
• Networking Operating System –
Network Operating Systems is typically installed in the server and
facilitate workstations in a network to share files, database, applications,
printers etc.
• Protocol Suite –
A protocol is a rule or guideline followed by each computer for data
communication. Protocol suite is a set of related protocols that are laid
down for computer networks. The two popular protocol suites are
−
o a. OSI Model ( Open System Interconnections)
o b. TCP / IP Model

16. Cables and Connectors
Cable is one way of transmission media which can transmit communication
signals. The wired network typology uses special type of cable to connect
computers on a network.
There are three types of cables used in transmission:
o Twisted pair cable
o Coaxial cable
o Fiber-optic cable
• Twisted pair cable
It is classified as Category 1, 2, 3, 4, 5, 5E, 6 and 7. Category 5E, 6
and 7 are high-speed cables that can transmit 1Gbps or more. -
• Coaxial cable
Coaxial cable more resembles like TV installation cable. It is more
expensive than twisted-pair cable but provide high data transmission
speed.
• Fiber-optic cable
It is a high-speed cable which transmits data using light beams
through a glass bound fibers. Fiber-optic cable is high data
transmission cable comparing to the other cable types. But the cost of
fiber optics is very expensive which can only be purchased and
installed on governmental level.
Conclusion
Whether you want to install a network at your office or home, these are
the required computer network components you need. Though,
depends on your situation some of the devices can be disregarded. For
home network using a Router is suitable since it also bundles a switch.