The TCP/IP model is a fundamental framework for computer networking.

It stands for Transmission

Control Protocol/Internet Protocol, which are the core protocols of the Internet. This model defines
how data is transmitted over networks, ensuring reliable communication between devices. It
consists of four layers: the Link Layer, the Internet Layer, the Transport Layer, and the Application
Layer. Each layer has specific functions that help manage different aspects of network
communication, making it essential for understanding and working with modern networks.

The main work of TCP/IP is to transfer the data of a computer from one device to another. The
main condition of this process is to make data reliable and accurate so that the receiver will receive
the same information which is sent by the sender. To ensure that, each message reaches its final
destination accurately, the TCP/IP model divides its data into packets and combines them at the
other end, which helps in maintaining the accuracy of the data while transferring from one end to
another end.
The diagrammatic comparison of the TCP/IP and OSI model is as follows:

1. Network Access Layer

The Network Access Layer represents a collection of applications that require network
communication. This layer is responsible for generating data and initiating connection requests. It
operates on behalf of the sender to manage data transmission, while the Network Access layer on
the receiver’s end processes and manages incoming data. In this article, we will focus on its role
from the receiver’s perspective.
The packet’s network protocol type, in this case, TCP/IP, is identified by network access layer. Error
prevention and “framing” are also provided by this layer. Point-to-Point Protocol (PPP) framing and
Ethernet IEEE 802.2 framing are two examples of data-link layer protocols.
2. Internet or Network Layer
This layer parallels the functions of OSI’s Network layer. It defines the protocols which are
responsible for the logical transmission of data over the entire network. The main protocols
residing at this layer are as follows:
 IP:IP stands for Internet Protocol and it is responsible for delivering packets from the source
host to the destination host by looking at the IP addresses in the packet headers. IP has 2
versions: IPv4 and IPv6. IPv4 is the one that most websites are using currently. But IPv6 is
growing as the number of IPv4 addresses is limited in number when compared to the
number of users.
 ICMP:ICMP stands for Internet Control Message Protocol. It is encapsulated within IP
datagrams and is responsible for providing hosts with information about network problems.
 ARP:ARP stands for Address Resolution Protocol. Its job is to find the hardware address of a
host from a known IP address. ARP has several types: Reverse ARP, Proxy ARP, Gratuitous
ARP, and Inverse ARP.
3. Transport Layer
The TCP/IP transport layer protocols exchange data receipt acknowledgments and retransmit
missing packets to ensure that packets arrive in order and without error. End-to-end
communication is referred to as such. Transmission Control Protocol (TCP) and User
Datagram Protocol are transport layer protocols at this level (UDP).
 TCP: Applications can interact with one another using TCP as though they were physically
connected by a circuit. TCP transmits data in a way that resembles character-by-character
transmission rather than separate packets. A starting point that establishes the connection,
the whole transmission in byte order, and an ending point that closes the connection make
up this transmission.
 UDP: The datagram delivery service is provided by UDP , the other transport layer protocol.
Connections between receiving and sending hosts are not verified by UDP. Applications that
transport little amounts of data use UDP rather than TCP because it eliminates the processes
of establishing and validating connections.
4. Application Layer
The Application Layer in the TCP/IP model combines the functions of three layers from
the OSI model: the Application, Presentation, and Session layers. It is responsible for end-
to-end communication and error-free delivery of data. It shields the upper-layer applications
from the complexities of data. The three main protocols present in this layer are:
 HTTP and HTTPS:HTTP stands for Hypertext transfer protocol. It is used by the World Wide
Web to manage communications between web browsers and servers. HTTPS stands for
HTTP-Secure. It is a combination of HTTP with SSL(Secure Socket Layer). It is efficient in cases
where the browser needs to fill out forms, sign in, authenticate, and carry out bank
transactions.
 SSH:SSH stands for Secure Shell. It is a terminal emulations software similar to Telnet. The
reason SSH is preferred is because of its ability to maintain the encrypted connection. It sets
up a secure session over a TCP/IP connection.
 NTP:NTP stands for Network Time Protocol. It is used to synchronize the clocks on our
computer to one standard time source. It is very useful in situations like bank transactions.
 Assume the following situation without the presence of NTP. Suppose you carry out a
transaction, where your computer reads the time at 2:30 PM while the server records it at
2:28 PM. The server can crash very badly if it’s out of sync.
Advantages of TCP/IP Model
 Interoperability : The TCP/IP model allows different types of computers and networks to
communicate with each other, promoting compatibility and cooperation among diverse
systems.
 Scalability : TCP/IP is highly scalable, making it suitable for both small and large networks,
from local area networks (LANs) to wide area networks (WANs) like the internet.
 Standardization : It is based on open standards and protocols, ensuring that different devices
and software can work together without compatibility issues.
 Flexibility : The model supports various routing protocols, data types, and communication
methods, making it adaptable to different networking needs.
 Reliability : TCP/IP includes error-checking and retransmission features that ensure reliable
data transfer, even over long distances and through various network conditions.
Disadvantages of TCP/IP Model
 Complex Configuration : Setting up and managing a TCP/IP network can be complex,
especially for large networks with many devices. This complexity can lead to configuration
errors.
 Security Concerns : TCP/IP was not originally designed with security in mind. While there are
now many security protocols available (such as SSL/TLS), they have been added on top of the
basic TCP/IP model, which can lead to vulnerabilities.
 Inefficiency for Small Networks : For very small networks, the overhead and complexity of
the TCP/IP model may be unnecessary and inefficient compared to simpler networking
protocols.
 Limited by Address Space : Although IPv6 addresses this issue, the older IPv4 system has a
limited address space, which can lead to issues with address exhaustion in larger networks.
The IEEE 802 is a set of protocols that is employed in the management of network protocols.In IEEE
standard IEEE 802.3, IEEE 802.4, and IEEE 802.5 are known as Ethernet, token bus, and token ring
networks. Each standard has its own topology, access control, and frame format for. In this article,
we will see these standards differences, advantages and disadvantages in detail.
What is IEEE 802.3?
IEEE 802. 3 is the standard of Ethernet that is used in the bus topology, whereby the devices are
connected directly to the communication line and are served in turns to enable them to access the
line. The CSMA/CD protocol is used by the network in order to manage the access acknowledging
collision while it is trying to put through data packets. For data sending, a device has to listen in
order not to interrupt some other device that may be transmitting. In case two devices are
transmitting at the same time, this is handled by collision detection that will ensure both devices
are made to stop transmitting, after which transmission is resumed after a certain interval of time
has been created.
Advantages of IEEE 802. 3
 Simple Protocol: CSMA/CD makes the ease of implementation of Ethernets.
 Cost-effective: IEEE 802. 3 uses basic technology without modems and other modem fancy
equipment; thus, it avoids the need to make extra expense in installation or for timely
maintenance.
 Widespread Adoption: Currently, Ethernet is one of the most popular established network
standards across the globe, which simply means that compatibility of Ethernet hardware and
software equipment will comprise switches, routers, and NICs.
Disadvantages of IEEE 802.3
 Decreased Efficiency at High Loads: If the number of devices in the network rises, then the
collision incidences are more frequent, hence pulling down the efficiency and the throughput
of large networks.
 Not Suitable for Real-Time Applications: Due to the fact that it is a collision-based system,
IEEE 802. 3 is not good for real-time operation requirements such as video conferencing and
live streaming, playing games, and so on.
 Limited Priority Support: Many networks do not have a mechanism of identifying which of
the data packets is more important than others. This is particularly the case where several
packages of data have to get to a specific destination before other nonurgent packages like
videos or voice do.
What is IEEE 802. 4?
IEEE 802. 4 explains what token bus standards are. Token passing is a protocol in which there is a
token—a specific data packet that passes through the stations that may be formed in a bus or tree
topology. Every station that possesses the token is allowed to transmit data, and therefore, there
can never be a collision of data. Thus, this token-passing method is more controllable with access
than to the CSMA/CD due to the structured store and forward nature of the protocol.
Advantages of IEEE 802. 4
 High Efficiency Under Heavy Load: Token Bus networks are specifically ideal for high-traffic
networks, as collisions are completely eliminated notwithstanding the size of the network.
 Prioritization of Stations: Standard: IEEE 802. 4 It makes some stations have charge over
others so as to ensure that the important jobs are processed first. This is important,
especially in industrial applications or the overall network, when some or certainly certain
data has to be updated in real time, for instance.
 Real-Time Traffic Support: This is because it allows real-time data transfer since the token
allows only those who have authorized access to the network; it is therefore ideal in the
industrial area that needs frequent data transfer.
Disadvantages of IEEE 802. 4
 Complex Protocol: Token passing protocol, which is much more complex to be implemented
in comparison to CSMA/CD. It employs other interface equipment, for instance, the modems,
and therefore, the general start-up and operational costs of such a system are usually high.
 Less Flexibility: Logical ring also suggests that for opposing Ethernet networks, adding or
removing the stations in the network is complicated.
 Obsolete in Modern Networks: Today the token bus networks are not widely used due to
Ethernet and are very easily substitutive by others faster, cheaper, and simpler networks.
What is IEEE 802. 5?
The token ring standard is one in which the stations aggregate IS in what can physically be referred
to as a ring where the token is passed from one station to another. Like in Token Bus, the token
grants permission to send, but the physical layout of the network is not the same. URLs in the ring
create positions for a token in the organization of the token ring.
Advantages of IEEE 802. 5
 No Collision: Like in Token Bus, Token Ring does not have collision data in the network
because only one station sends data in the network at a particular period of time.
 Support for Large Data Transfers: Other vile standards which he pointed that regulated the
size of fields in the data frames differed from the IEEE 802. 5 is for variable size data frames
which makes its use useful in instances that involve large data frames such as file transfer or
a video stream.
 Real-Time and Interactive Applications: Because there is no limit in data field size and very
efficient network topology, Token Ring most suits for real-time applications like video
conferencing, online games, and client-server activities.
Disadvantages of IEEE 802. 5
 Moderate Complexity: Relative to the other network, the token ring can be considered as
moderate complex because, in order for the communication between the stations to occur
properly, modems are needed. This is time-consuming and expensive, hence contributing to
the total cost of developing the network.
 Dependency on Token: Of course, the entire network is associated with the functionality of
the token. The problem with this setup is that if the token has been lost or becomes
corrupted, the network halts and would take time before sorting, which in the process
creates downtimes.
 Less Popular in Modern Networks: Token Ring networks are comparatively costly and
elaborate than the Ethernet networks and hence are not so widely used as the latter.
Ethernet dominates current-day networks because of the simplicity of the technology and
the fact that it is cheaper than the token ring.
Difference between IEEE 802.3, 802.4 and 802.5
IEEE 802.3 IEEE 802.4 IEEE 802.5

Topology used in IEEE

Topology used in IEEE 802.3 is Topology used in IEEE 802.5 is Ring
802.4 is Bus or Tree
Bus Topology. Topology.
Topology.

Size of the frame

Size of the frame format in IEEE Frame format in IEEE 802.5
format in IEEE 802.4
802.3 standard is 1572 bytes. standard is of the variable size.
standard is 8202 bytes.

There is no priority given in this It supports priorities to

In IEEE 802.5 priorities are possible
standard. stations.

Size of the data field is 0 to Size of the data field is No limit is on the size of the data
1500 bytes. 0 to 8182 bytes. field.

Minimum frame required is 64 It can handle short It supports both short and large
bytes. minimum frames. frames.

Efficiency decreases when

Throughput &
speed increases and Throughput & efficiency at very high
efficiency at very high
throughput is affected by the loads are outstanding.
loads are outstanding.
collision.

Modems are required Like IEEE 802.4, modems are also

Modems are not required.
in this standard. required in it.

Protocol is extremely
Protocol is very simple. Protocol is moderately complex.
complex.

It is not applicable on Real time It can be applied for Real time

applications, interactive It is applicable to Real applications and interactive
Applications and Client-Server time traffic. applications because there is no
applications. limitation on the size of data.
Difference Between IPv4 and IPv6
IPv4 IPv6

IPv4 has a 32-bit

IPv6 has a 128-bit address length
address length

It Supports Manual
It supports Auto and renumbering
and DHCP address
address configuration
configuration

In IPv4 end to end,

In IPv6 end-to-end, connection integrity is
connection integrity is
Achievable
Unachievable

It can generate
The address space of IPv6 is quite large it
4.29×10 9 address
can produce 3.4×10 38 address space
space

The Security feature is

IPSEC is an inbuilt security feature in the
dependent on the
IPv6 protocol
application

Address representation Address representation of IPv6 is in

of IPv4 is in decimal hexadecimal

Fragmentation perform
In IPv6 fragmentation is performed only
ed by Sender and
by the sender
forwarding routers

In IPv4 Packet flow In IPv6 packet flow identification are

identification is not Available and uses the flow label field in
available the header

In IPv4 checksum field In IPv6 checksum field is not available

 IPv4 IPv6

is available

It has a broadcast
In IPv6 multicast and anycast message
Message Transmission
transmission scheme is available
Scheme

In IPv4 Encryption and

In IPv6 Encryption and Authentication are
Authentication facility
provided
not provided

IPv4 has a header of

IPv6 has a header of 40 bytes fixed
20-60 bytes.

IPv4 can be converted

Not all IPv6 can be converted to IPv4
to IPv6

IPv4 consists of 4 fields

IPv6 consists of 8 fields, which are
which are separated by
separated by a colon (:)
addresses dot (.)

IPv4’s IP addresses are

divided into five
IPv6 does not have any classes of the IP
different classes. Class
address.
A , Class B, Class C,
Class D , Class E.

IPv4 supports
VLSM( Variable Length IPv6 does not support VLSM.
subnet mask ).

Example of IPv6:
Example of IPv4:
2001:0000:3238:DFE1:0063:0000:0000:F
66.94.29.13
EFB
IP stands for Internet Protocol and v4 stands for Version Four (IPv4). IPv4 was the primary version
brought into action for production within the ARPANET in 1983. IP version four addresses are 32-bit
integers which will be expressed in decimal notation. In this article, we will discuss about IPv4
datagram header.
Characteristics of IPv4
 IPv4 could be a 32-Bit IP Address.
 IPv4 could be a numeric address, and its bits are separated by a dot.
 The number of header fields is twelve and the length of the header field is twenty.
 It has Unicast, broadcast, and multicast style of addresses.
 IPv4 supports VLSM (Virtual Length Subnet Mask).
 IPv4 uses the Post Address Resolution Protocol to map to the MAC address.
 RIP may be a routing protocol supported by the routed daemon.
 Networks ought to be designed either manually or with DHCP.
 Packet fragmentation permits from routers and causing host.
IPv4 Datagram Header
 VERSION: Version of the IP protocol (4 bits), which is 4 for IPv4
 HLEN: IP header length (4 bits), which is the number of 32 bit words in the header. The
minimum value for this field is 5 and the maximum is 15.
 Type of service: Low Delay, High Throughput, Reliability (8 bits)
 Total Length: Length of header + Data (16 bits), which has a minimum value 20 bytes and the
maximum is 65,535 bytes.
 Identification: Unique Packet Id for identifying the group of fragments of a single IP
datagram (16 bits)
 Flags: 3 flags of 1 bit each : reserved bit (must be zero), do not fragment flag, more
fragments flag (same order)
 Fragment Offset: Represents the number of Data Bytes ahead of the particular fragment in
the particular Datagram. Specified in terms of number of 8 bytes, which has the maximum
value of 65,528 bytes.
 Time to live: Datagram’s lifetime (8 bits), It prevents the datagram to loop through the
network by restricting the number of Hops taken by a Packet before delivering to the
Destination.
 Protocol: Name of the protocol to which the data is to be passed (8 bits)
  Header Checksum: 16 bits header checksum for checking errors in the datagram header
 Source IP address: 32 bits IP address of the sender
 Destination IP address: 32 bits IP address of the receiver
 Option: Optional information such as source route, record route. Used by the Network
administrator to check whether a path is working or not.

IPv4 Datagram Header