Different Types of Transmission Mediums
Data is represented by computers and other telecommunication devices using signals. Signals are
transmitted in the form of electromagnetic energy from one device to another. Electromagnetic
signals travel through vacuum, air or other transmission mediums to move from one point to
another(from sender to receiver).
Electromagnetic energy (includes electrical and magnetic fields) consists of power, voice, visible
light, radio waves, ultraviolet light, gamma rays etc.
Transmission medium is the means through which we send our data from one place to another.
The first layer (physical layer) of Communication Networks OSI Seven layer model is dedicated
to the transmission media, we will study the OSI Model later.
Wired or Bounded Transmission Mediums
Wired or the bounded transmission mediums use physical cables to transmit data. The key types
are:
1. Twisted Pair Cable
•
•
Description: Consists of pairs of insulated copper wires twisted together.
Types:
o Unshielded Twisted Pair (UTP): Common in Ethernet networks. Vulnerable to
electromagnetic interference (EMI).
Page 1 of 25
o
•
•
Shielded Twisted Pair (STP): Has a protective shield to reduce EMI. Used in
environments with high interference.
Speed & Distance: Supports speeds up to 10 Gbps over short distances (up to 100 meters
for Cat6a cables).
Applications: Local Area Networks (LANs), telecommunication networks.
2. Coaxial Cable
•
•
•
Description: A single copper conductor at the center, surrounded by insulation, a
metallic shield, and an outer insulating layer.
Speed & Distance: Can support speeds up to 10 Gbps and distances up to 500 meters.
Applications: Cable television networks, early Ethernet networks (10BASE2,
10BASE5).
3. Fiber Optic Cable
•
•
•
•
Description: Uses light pulses to transmit data through strands of glass or plastic fibers.
Types:
o Single-mode Fiber (SMF): Has a small core, supports long-distance
communication (up to 100 km).
o Multi-mode Fiber (MMF): Has a larger core, supports shorter distances (up to 2
km).
Speed & Distance: Supports very high speeds (up to 100 Gbps) over long distances.
Applications: Backbone networks, high-speed internet connections, long-distance
telecommunications.
Wireless or Unbounded Transmission Mediums
Wireless or Unbounded transmission mediums use electromagnetic waves to transmit data
without physical cables. The key types are:
1. Radio Waves
•
•
•
Description: Uses radio frequencies (RF) to transmit data over the air.
Range: Can vary from a few meters (Bluetooth) to several kilometers (Wi-Fi, cellular
networks).
Applications: Wi-Fi, cellular networks (2G, 3G, 4G, 5G), Bluetooth.
2. Microwaves
•
•
Description: Uses high-frequency radio waves (1 GHz to 300 GHz) for point-to-point
communication.
Range: Supports long-distance communication with line-of-sight transmission.
Page 2 of 25
•
Applications: Satellite communication, point-to-point links, microwave ovens.
3. Infrared (IR)
•
•
•
Description: Uses infrared light to transmit data over short distances.
Range: Limited to line-of-sight and short distances (a few meters).
Applications: Remote controls, short-range communication between devices (like
infrared ports on laptops).
4. Satellite Communication
•
•
•
Description: Uses satellites in space to relay data between ground stations.
Range: Global coverage, ideal for long-distance and remote area communication.
Applications: Global Positioning Systems (GPS), satellite internet, television
broadcasting.
Factors to be considered while selecting a Transmission Medium
1. Transmission Rate
2. Cost and Ease of Installation
3. Resistance to Environmental Conditions
4. Distances
5. Security of the Network
Bounded or Wired Transmission Medium
Guided medium, which are those that provide a conduit from one device to another,
include Twisted-Pair Cable, Coaxial Cable, and Fibre-Optic Cable.
A signal travelling along any of these medium is directed and contained by the physical limits of
the medium. Twisted-pair and coaxial cable use metallic (copper) conductors that accept and
transport signals in the form of electric current. Optical fibre is a cable that accepts and
transports signals in the form of light.
1. Twisted Pair Cable
This cable is the most commonly used and is cheaper than others. It is lightweight, cheap, can be
installed easily, and they support many different types of network. Some important points :
Page 3 of 25
•
Its frequency range is 0 to 3.5 kHz.
•
Typical attenuation is 0.2 dB/Km @ 1kHz.
•
Typical delay is 50 µs/km.
•
Repeater spacing is 2km.
A twisted pair consists of two conductors(normally copper), each with its own plastic insulation,
twisted together. One of these wires is used to carry signals to the receiver, and the other is used
only as ground reference. The receiver uses the difference between the two. In addition to the
signal sent by the sender on one of the wires, interference(noise) and crosstalk may affect both
wires and create unwanted signals. If the two wires are parallel, the effect of these unwanted
signals is not the same in both wires because they are at different locations relative to the noise
or crosstalk sources. This results in a difference at the receiver.
Twisted Pair is of two types:
•
Unshielded Twisted Pair (UTP)
•
Shielded Twisted Pair (STP)
1.1. Unshielded Twisted Pair Cable
It is the most common type of telecommunication when compared with Shielded Twisted Pair
Cable which consists of two conductors usually copper, each with its own colour plastic
insulator. Identification is the reason behind coloured plastic insulation.
UTP cables consist of 2 or 4 pairs of twisted cable. Cable with 2 pair use RJ-11 connector and 4
pair cable use RJ-45 connector.
Page 4 of 25
Advantages of Unshielded Twisted Pair Cable
•
Installation is easy
•
Flexible
•
Cheap
•
It has high speed capacity,
•
100 meter limit
•
Higher grades of UTP are used in LAN technologies like Ethernet.
It consists of two insulating copper wires (1mm thick). The wires are twisted together in a helical
form to reduce electrical interference from similar pair.
Disadvantages of Unshielded Twisted Pair Cable
•
Bandwidth is low when compared with Coaxial Cable
•
Provides less protection from interference.
1.2. Shielded Twisted Pair Cable
This cable has a metal foil or braided-mesh covering which encases each pair of insulated
conductors. Electromagnetic noise penetration is prevented by metal casing. Shielding also
eliminates crosstalk (explained in KEY TERMS Chapter).
Page 5 of 25
It has same attenuation as unshielded twisted pair. It is faster the unshielded and coaxial cable. It
is more expensive than coaxial and unshielded twisted pair.
Advantages of Shielded Twisted Pair Cable
•
Easy to install
•
Performance is adequate
•
Can be used for Analog or Digital transmission
•
Increases the signalling rate
•
Higher capacity than unshielded twisted pair
•
Eliminates crosstalk
Disadvantages of Shielded Twisted Pair Cable
•
Difficult to manufacture
•
Heavy
Performance of Shielded Twisted Pair Cable
One way to measure the performance of twisted-pair cable is to compare attenuation versus
frequency and distance. As shown in the below figure, a twisted-pair cable can pass a wide range
of frequencies. However, with increasing frequency, the attenuation, measured in decibels per
Page 6 of 25
kilometre (dB/km), sharply increases with frequencies above 100kHz. Note that gauge is a
measure of the thickness of the wire.
Applications of Shielded Twisted Pair Cable
•
In telephone lines to provide voice and data channels. The DSL lines that are used by the
telephone companies to provide high-data-rate connections also use the high-bandwidth
capability of unshielded twisted-pair cables.
•
Local Area Network, such as 10Base-T and 100Base-T, also use twisted-pair cables.
2. Coaxial Cable
Coaxial is called by this name because it contains two conductors that are parallel to each other.
Copper is used in this as centre conductor which can be a solid wire or a standard one. It is
surrounded by PVC installation, a sheath which is encased in an outer conductor of metal foil,
barid or both.
Outer metallic wrapping is used as a shield against noise and as the second conductor which
completes the circuit. The outer conductor is also encased in an insulating sheath. The outermost
part is the plastic cover which protects the whole cable.
Here the most common coaxial standards.
•
50-Ohm RG-7 or RG-11 : used with thick Ethernet.
•
50-Ohm RG-58 : used with thin Ethernet
•
75-Ohm RG-59 : used with cable television
•
93-Ohm RG-62 : used with ARCNET.
2.1. Coaxial Cable Standards
Coaxial cables are categorized by their Radio Government(RG) ratings. Each RG number
denotes a unique set of physical specifications, including the wire gauge of the inner conductor,
the thickness and the type of the inner insulator, the construction of the shield, and the size and
type of the outer casing. Each cable defined by an RG rating is adapted for a specialized
function, as shown in the table below:
Page 7 of 25
2.2. Coaxial Cable Connectors
To connect coaxial cable to devices, we need coaxial connectors. The most common type of
connector used today is the Bayonet Neill-Concelman (BNC) connector. The below figure shows
3 popular types of these connectors: the BNC Connector, the BNC T connector and the BNC
terminator.
The BNC connector is used to connect the end of the cable to the device, such as a TV set. The
BNC T connector is used in Ethernet networks to branch out to a connection to a computer or
other device. The BNC terminator is used at the end of the cable to prevent the reflection of the
signal.
There are two types of Coaxial cables:
1. BaseBand
This is a 50 ohm (Ω) coaxial cable which is used for digital transmission. It is mostly used for
LAN's. Baseband transmits a single signal at a time with very high speed. The major drawback is
that it needs amplification after every 1000 feet.
2. BroadBand
This uses analog transmission on standard cable television cabling. It transmits several
simultaneous signal using different frequencies. It covers large area when compared with
Baseband Coaxial Cable.
Advantages of Coaxial Cable
•
Bandwidth is high
•
Used in long distance telephone lines.
•
Transmits digital signals at a very high rate of 10Mbps.
•
Much higher noise immunity
Page 8 of 25
•
Data transmission without distortion.
•
The can span to longer distance at higher speeds as they have better shielding when
compared to twisted pair cable
Disadvantages of Coaxial Cable
•
Single cable failure can fail the entire network.
•
Difficult to install and expensive when compared with twisted pair.
•
If the shield is imperfect, it can lead to grounded loop.
Performance of Coaxial Cable
We can measure the performance of a coaxial cable in same way as that of Twisted Pair Cables.
From the below figure, it can be seen that the attenuation is much higher in coaxial cable than in
twisted-pair cable. In other words, although coaxial cable has a much higher bandwidth, the
signal weakens rapidly and requires the frequent use of repeaters.
Applications of Coaxial Cable
•
Coaxial cable was widely used in analog telephone networks, where a single coaxial
network could carry 10,000 voice signals.
•
Cable TV networks also use coaxial cables. In the traditional cable TV network, the
entire network used coaxial cable. Cable TV uses RG-59 coaxial cable.
•
In traditional Ethernet LANs. Because of it high bandwidth, and consequence high data
rate, coaxial cable was chosen for digital transmission in early Ethernet LANs. The
10Base-2, or Thin Ethernet, uses RG-58 coaxial cable with BNC connectors to transmit
data at 10Mbps with a range of 185 m.
3. Fiber Optic Cable
A fibre-optic cable is made of glass or plastic and transmits signals in the form of light.
For better understanding we first need to explore several aspects of the nature of light.
Light travels in a straight line as long as it is mobbing through a single uniform substance. If ray
of light travelling through one substance suddenly enters another substance (of a different
density), the ray changes direction.
Page 9 of 25
The below figure shows how a ray of light changes direction when going from a more dense to a
less dense substance.
Bending of a light ray
As the figure shows:
•
If the angle of incidence I(the angle the ray makes with the line perpendicular to the
interface between the two substances) is less than the critical angle, the ray refracts and
moves closer to the surface.
•
If the angle of incidence is greater than the critical angle, the ray reflects(makes a turn)
and travels again in the denser substance.
•
If the angle of incidence is equal to the critical angle, the ray refracts and moves
parallel to the surface as shown.
Note: The critical angle is a property of the substance, and its value differs from one substance
to another.
Optical fibres use reflection to guide light through a channel. A glass or plastic core is
surrounded by a cladding of less dense glass or plastic. The difference in density of the two
materials must be such that a beam of light moving through the core is reflected off the cladding
instead of being refracted into it.
Internal view of an Optical fibre
3.1. Propagation Modes of Fiber Optic Cable
Current technology supports two modes(Multimode and Single mode) for propagating light
along optical channels, each requiring fibre with different physical characteristics. Multimode
can be implemented in two forms: Step-index and Graded-index.
Multimode Propagation Mode
Multimode is so named because multiple beams from a light source move through the core in
different paths. How these beams move within the cable depends on the structure of the core as
shown in the below figure.
Page 10 of 25
•
In multimode step-index fibre, the density of the core remains constant from the centre
to the edges. A beam of light moves through this constant density in a straight line until it
reaches the interface of the core and the cladding.
The term step-index refers to the suddenness of this change, which contributes to the
distortion of the signal as it passes through the fibre.
•
In multimode graded-index fibre, this distortion gets decreases through the cable. The
word index here refers to the index of refraction. This index of refraction is related to the
density. A graded-index fibre, therefore, is one with varying densities. Density is highest
at the centre of the core and decreases gradually to its lowest at the edge.
Single Mode
Single mode uses step-index fibre and a highly focused source of light that limits beams to a
small range of angles, all close to the horizontal. The single-mode fibre itself is manufactured
with a much smaller diameter than that of multimode fibre, and with substantially lower density.
The decrease in density results in a critical angle that is close enough to 90 degree to make the
propagation of beams almost horizontal.
Fibre Sizes for Fiber Optic Cable
Optical fibres are defined by the ratio of the diameter or their core to the diameter of their
cladding, both expressed in micrometers. The common sizes are shown in the figure below:
Fibre Optic Cable Connectors
There are three types of connectors for fibre-optic cables, as shown in the figure below.
The Subscriber Channel(SC) connector is used for cable TV. It uses push/pull locking system.
The Straight-Tip(ST) connector is used for connecting cable to the networking devices. MT-RJ
is a connector that is the same size as RJ45.
Advantages of Fibre Optic Cable
Fibre optic has several advantages over metallic cable:
•
Higher bandwidth
Page 11 of 25
•
Less signal attenuation
•
Immunity to electromagnetic interference
•
Resistance to corrosive materials
•
Light weight
•
Greater immunity to tapping
Disadvantages of Fibre Optic Cable
There are some disadvantages in the use of optical fibre:
•
Installation and maintenance
•
Unidirectional light propagation
•
High Cost
Performance of Fibre Optic Cable
Attenuation is flatter than in the case of twisted-pair cable and coaxial cable. The performance is
such that we need fewer(actually one tenth as many) repeaters when we use the fibre-optic cable.
Applications of Fibre Optic Cable
•
Often found in backbone networks because its wide bandwidth is cost-effective.
•
Some cable TV companies use a combination of optical fibre and coaxial cable thus
creating a hybrid network.
•
Local-area Networks such as 100Base-FX network and 1000Base-X also use fibre-optic
cable.
Types of Computer Networks
Computer Network can be of following 5 types:
1. Local Area Network (LAN)
2. Wide Area Network (WAN)
3. Wireless
Page 12 of 25
1. Local Area Network (LAN)
It is also called LAN and designed for small physical areas such as an office, group of buildings
or a factory. LANs are used widely as it is easy to design and to troubleshoot. Personal
computers and workstations are connected to each other through LANs. We can use different
types of topologies through LAN, these are Star, Ring, Bus, Tree etc.
LAN can be a simple network like connecting two computers, to share files and network among
each other while it can also be as complex as interconnecting an entire building.
LAN networks are also widely used to share resources like printers, shared hard-drive etc.
Characteristics of LAN
•
LAN's are private networks, not subject to tariffs or other regulatory controls.
•
LAN's operate at relatively high speed when compared to the typical WAN.
•
There are different types of Media Access Control methods in a LAN, the prominent ones
are Ethernet, Token ring.
•
It connects computers in a single building, block or campus, i.e. they work in a restricted
geographical area.
Applications of LAN
•
One of the computer in a network can become a server serving all the remaining
computers called clients. Software can be stored on the server and it can be used by the
remaining clients.
•
Connecting Locally all the workstations in a building to let them communicate with each
other locally without any internet access.
Page 13 of 25
•
Sharing common resources like printers etc are some common applications of LAN.
Advantages of LAN
•
Resource Sharing: Computer resources like printers, modems, DVD-ROM drives and
hard disks can be shared with the help of local area networks. This reduces cost and
hardware purchases.
•
Software Applications Sharing: It is cheaper to use same software over network instead
of purchasing separate licensed software for each client a network.
•
Easy and Cheap Communication: Data and messages can easily be transferred over
networked computers.
•
Centralized Data: The data of all network users can be saved on hard disk of the server
computer. This will help users to use any workstation in a network to access their data.
Because data is not stored on workstations locally.
•
Data Security: Since, data is stored on server computer centrally, it will be easy to
manage data at only one place and the data will be more secure too.
•
Internet Sharing: Local Area Network provides the facility to share a single internet
connection among all the LAN users. In Net Cafes, single internet connection sharing
system keeps the internet expenses cheaper.
Disadvantages of LAN
•
High Setup Cost: Although the LAN will save cost over time due to shared computer
resources, but the initial setup costs of installing Local Area Networks is high.
•
Privacy Violations: The LAN administrator has the rights to check personal data files of
each and every LAN user. Moreover he can check the internet history and computer use
history of the LAN user.
•
Data Security Threat: Unauthorised users can access important data of an organization
if centralized data repository is not secured properly by the LAN administrator.
•
LAN Maintenance Job: Local Area Network requires a LAN Administrator because,
there are problems of software installations or hardware failures or cable disturbances in
Local Area Network. A LAN Administrator is needed at this full time job.
•
Covers Limited Area: Local Area Network covers a small area like one office, one
building or a group of nearby buildings.
Page 14 of 25
Wide Area Network (WAN)
It is also called WAN. WAN can be private or it can be public leased network. It is used for the
network that covers large distance such as cover states of a country. It is not easy to design and
maintain. Communication medium used by WAN are PSTN or Satellite links. WAN operates on
low data rates.
Characteristics of WAN
•
It generally covers large distances(states, countries, continents).
•
Communication medium used are satellite, public telephone networks which are
connected by routers.
•
Owned by a group of companies
Advantages of WAN
•
Covers a large geographical area so long distance business can connect on the one
network.
•
Shares software and resources with connecting workstations.
•
Messages can be sent very quickly to anyone else on the network. These messages can
have picture, sounds or data included with them(called attachments).
•
Expensive things(such as printers or phone lines to the internet) can be shared by all the
computers on the network without having to buy a different peripheral for each computer.
Page 15 of 25
•
Everyone on the network can use the same data. This avoids problems where some users
may have older information than others.
Disadvantages of WAN
•
Need a good firewall to restrict outsiders from entering and disrupting the network.
•
Setting up a network can be an expensive, slow and complicated. The bigger the network
the more expensive it is.
•
Once set up, maintaining a network is a full-time job which requires network supervisors
and technicians to be employed.
•
Security is a real issue when many different people have the ability to use information
from other computers. Protection against hackers and viruses adds more complexity and
expense.
Connection Oriented and Connectionless Services
In a transmission network, the communication between layers can be connection oriented or
connectionless.
1. Connection Oriented Service
2. Connectionless Services
Connection Oriented Services
There is a sequence of operation to be followed by the users of connection oriented service.
These are:
1. Connection is established.
2. Information is sent.
3. Connection is released.
In connection oriented service we have to establish a connection before starting the
communication. When connection is established, we send the message or the information and
then we release the connection.
Connection oriented service is more reliable than connectionless service. We can send the
message in connection oriented service if there is an error at the receivers end. Example of
connection oriented is TCP (Transmission Control Protocol) protocol.
Page 16 of 25
Connection Less Services
It is similar to the postal services, as it carries the full address where the message (letter) is to be
carried. Each message is routed independently from source to destination. The order of message
sent can be different from the order received.
In connectionless the data is transferred in one direction from source to destination without
checking that destination is still there or not or if it prepared to accept the message.
Authentication is not needed in this. Example of Connectionless service is UDP (User Datagram
Protocol) protocol.
Difference: Connection oriented and Connectionless service
1. In connection oriented service authentication is needed, while connectionless service
does not need any authentication.
2. Connection oriented protocol makes a connection and checks whether message is
received or not and sends again if an error occurs, while connectionless service protocol
does not guarantees a message delivery.
3. Connection oriented service is more reliable than connectionless service.
4. Connection oriented service interface is stream based and connectionless is message
based.
Reference Models in Computer Networks
In this tutorial, we will be covering reference models in Computer Networks.
In the past couple of decades, many networks that were built used different hardware and
software implementations as a result they were incompatible, and thus it became difficult for
networks using different specifications to communicate with each other.
In order to address this problem: the incompatibility of networks and their inability to
communicate with each other. The International Organization of Standardization(ISO)
researched various network schemes. After that, they recognized there is a need to create a
Network Model that will help vendors to create interoperable implementations of the network.
Let us now understand what is a Reference Model?
Reference Model
It is a conceptual layout mainly used to describe how the communication between devices should
occur.
Page 17 of 25
•
•
One of the main advantages of the reference model is that it defines the standards for
building components of the network thereby permitting multiple-vendor development.
Reference models define which functions should be performed at each layer of the model
and thus they promote standardization.
The most important reference models are:
1. OSI reference model.
2. TCP/IP reference model.
Introduction to ISO-OSI Model
There are many users who use computer networks and are located all over the world. To ensure
national and worldwide data communication ISO (ISO stands for International Organization of
Standardization.) developed this model. This is called a model for open system interconnection
(OSI) and is normally called an OSI model. OSI model architecture consists of seven layers. It
defines seven layers or levels in a complete communication system. These seven layers are
interconnected to each other. OSI Reference model is explained in detail in another chapter.
Seven Layers of the OSI Model are as follows:
•
•
•
•
•
•
•
Physical Layer
Data Link Layer
Network Layer
Transport Layer
Session Layer
Presentation Layer
Application Layer
Page 18 of 25
Introduction to TCP/IP Reference Model
TCP/IP is transmission control protocol and internet protocol. Protocols are a set of rules which
govern every possible communication over the internet. These protocols describe the movement
of data between the host computers or the internet and offer simple naming and addressing
schemes.
TCP/IP Reference model is explained in detail in another chapter.
Layers in the TCP/IP Model are as follows:
•
•
•
•
Network access layer
Internet layer
Transport layer
Application layer
Page 19 of 25
Comparison of OSI and TCP/IP Reference Model
In this tutorial, we will cover the comparison between the two reference Models that is OSI
model and the TCP/IP model in Computer networks.
Open System Interconnection (OSI) is commonly known as the OSI model.
•
•
•
•
The OSI Model is mainly a conceptual framework and is used to describe the functions of
a networking system.
The OSI Model consists of seven layers where each layer performs its specific function.
This model was published by ISO in 1984.
This model mainly divides the giant task into seven manageable and smaller tasks. After
that, each layer in the model is assigned a particular task.
The ISO-OSI model is a seven-layer architecture. It defines seven layers or levels in a complete
communication system. They are:
1.
2.
3.
4.
5.
6.
7.
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Datalink Layer
Physical Layer
Page 20 of 25
OSI Model
TCP/IP Model
TCP/IP is Transmission Control Protocol and Internet Protocol was developed by the
Department of Defence's Project Research Agency (ARPA, later DARPA) as a part of a
research project of network interconnection to connect remote machines.
The features that stood out during the research, which led to making the TCP/IP reference model
were:
•
•
Support for a flexible architecture. Adding more machines to a network was easy.
The network was robust, and connections remained intact until the source and destination
machines were functioning.
The overall idea was to allow one application on one computer to talk to(send data packets)
another application running on a different computer.
Page 21 of 25
TCP/IP Model
Now it's time to compare both the reference model that we have learned till now. Let's start by
addressing the similarities that both of these models have.
Following are some similarities between OSI Reference Model and TCP/IP Reference Model.
•
•
•
•
•
Both have layered architecture.
Layers provide similar functionalities.
Both are protocol stack.
Both are reference models.
Both have Predefined Standards.
Difference between OSI and TCP/IP Reference Model
Following are some major differences between OSI Reference Model and TCP/IP Reference
Model, with diagrammatic comparison below.
Page 22 of 25
OSI(Open System Interconnection)
TCP/IP(Transmission Control Protocol / Internet
Protocol)
1. OSI is a generic, protocol-independent
standard, acting as a communication
gateway between the network and enduser.
1. TCP/IP model is based on standard protocols
around which the Internet has developed. It is a
communication protocol, which allows the
connection of hosts over a network.
2. In the OSI model the transport layer
guarantees the delivery of packets.
2. In the TCP/IP model the transport layer does not
guarantee the delivery of packets. Still, the TCP/IP
model is more reliable.
3. Follows vertical approach.
3. Follows horizontal approach.
4. OSI model has a separate Presentation
layer and Session layer.
4. TCP/IP does not have a separate Presentation layer
or Session layer.
5. Transport Layer is Connection Oriented.
5. Transport Layer is both Connection-Oriented and
Connectionless.
6. Network Layer is both ConnectionOriented and Connectionless.
6. Network Layer is Connectionless.
7. OSI is a reference model around which
the networks are built. Generally, it is used
as a guidance tool.
7. TCP/IP model is, in a way implementation of the
OSI model.
Page 23 of 25
8. Network layer of the OSI model
provides both connection-oriented and
connectionless service.
8. The Network layer in the TCP/IP model provides
connectionless service.
9. Th TCP/IP model also provides
standardization to many devices such as a
router, motherboard, switches, and some
other hardware devices.
9.This model does not provide any such kind of
standardization of the devices. But this model
provides a connection between various computers
10. Protocols are hidden in the OSI model
and are easily replaced as the technology
changes.
10. In TCP/IP replacing protocol is not easy.
11. OSI model defines services, interfaces,
and protocols very clearly and makes a
clear distinction between them. It is
protocol independent.
11. In TCP/IP, services, interfaces, and protocols are
not clearly separated. It is also protocol-dependent.
12. It has 7 layers
12. It has 4 layers
13.The usage of the OSI reference model
is low.
13. On the other hand TCP/IP model is highly used.
14.OSI model has a problem of fitting the
protocols into the model.
14. TCP/IP model does not fit any protocol
Page 24 of 25
Page 25 of 25