TCP/IP Protocols and Layers

1. PROTOCOL ARCHITECTURE,TCP/IP,
AND INTERNET-BASED APPLICATIONS
Ayyaz Yaqoob (Lecturer)
Department of Computer Science
UOS Mandi Bahauddin Campus

2. Key Points
• A protocol architecture is the layered structure of hardware
and software
• that supports the exchange of data between systems and
supports distributed applications, such as electronic mail and
file transfer
• At each layer of a protocol architecture, one or more common
protocols are implemented

3. Key Points
• Each protocol provides a set of rules for the exchange of data
between systems
• The most widely used protocol architecture is the TCP/IP
protocol and seven-layer OSI model

4. THE NEED FOR A PROTOCOL ARCHITECTURE
• When computers, terminals, and/or other data processing
devices exchange data, the procedures involved can be quite
complex
• There must be a data path between the two computers
• The source system must either activate the direct data
communication path or inform the communication network of
the identity of the desired destination system
• The source system must ascertain that the destination system
is prepared to receive data
• If the file formats used on the two systems are different, one
or the other system must perform a format translation
function

5. THE NEED FOR A PROTOCOL ARCHITECTURE
• Communication is achieved by having the corresponding,
layers in two systems
• The peer layers communicate by means of formatted blocks of
data that obey a set of rules or conventions known as a
protocol.
• The key features of a protocol are as follows:
• Syntax: Concerns the format of the data blocks
• Semantics: Includes control information for coordination and
error handling
• Timing: Includes speed matching and sequencing

6. THE TCP/IP PROTOCOL ARCHITECTURE
• The Transmission Control Protocol (TCP/IP) protocol
architecture is a result of protocol research and development
conducted on the experimental packet-switched network
• In general terms, communications can be said to involve three
agents: applications, computers and networks
• In TCP/IP five relatively independent layers
• Physical layer
• Network access layer
• Internet layer
• Host-to-host, or transport layer
• Application layer

7. Physical layer of TCP/IP
• The physical layer covers the physical interface between a data
transmission device (e.g., workstation, computer) and a
transmission medium or network
• This layer is concerned with specifying the characteristics
• of the transmission medium
• the nature of the signals
• the data rate
• and related matters

8. Network access layer
• The network access layer is concerned with the exchange of
data between an end system (server, workstation, etc.) and
the network to which it is attached
• The sending computer must provide the network with the
address of the destination computer
• The network access layer is concerned with access to and
routing data across a network for two end systems attached to
the same network

9. Network access layer
• The Network Interface layer (also called the Network Access
layer) is responsible for
• placing TCP/IP packets on the network medium and receiving
TCP/IP packets off the network medium
• TCP/IP was designed to be independent of the network access
method, frame format, and medium

10. Internet layer
• The Internet layer is responsible for addressing, packaging,
and routing functions
• The core protocols of the Internet layer are IP, ARP, ICMP, and
IGMP.
• The internet layer perform its functionality. where two devices
are attached to different networks, procedures are needed to
allow data to traverse multiple interconnected networks

11. Internet layer
• The Internet Protocol (IP) is used at this layer to provide the
routing function across multiple networks
• Internet Protocol (IP) is implemented not only in the end
systems but also in routers
• A router is a processor that connects two networks and whose
primary function is to relay data from one network to the
other on its route from the source to the destination end
system

12. Internet layer
• The Internet Protocol (IP) is a routable protocol responsible for
IP addressing, routing, and the fragmentation and reassembly
of packets.
• The Address Resolution Protocol (ARP) is responsible for the
resolution of the Internet layer address to the Network
Interface layer address such as a hardware address.
• The Internet Control Message Protocol (ICMP) is responsible
for providing diagnostic functions and reporting errors due to
the unsuccessful delivery of IP packets.
• The Internet Group Management Protocol (IGMP) is
responsible for the management of IP multicast groups.

13. Host-to-host, or transport layer
• The Transport layer (also known as the Host-to-Host Transport
layer) is responsible for providing the Application layer with
session and datagram communication services
• The core protocols of the Transport layer are Transmission
Control Protocol (TCP) and the User Datagram Protocol (UDP)
• TCP provides a one-to-one, connection-oriented, reliable
communications service. TCP is responsible for the
establishment of a TCP connection, the sequencing and
acknowledgment of packets sent, and the recovery of packets
lost during transmission.

14. Host-to-host, or transport layer
• UDP provides a one-to-one or one-to-many, connectionless,
unreliable communications service. UDP is used when the
amount of data to be transferred is small (such as the data
that would fit into a single packet), when the overhead of
establishing a TCP connection is not desired or when the
applications or upper layer protocols provide reliable delivery

15. Application layer
• The Application layer provides applications the ability to
access the services of the other layers and defines the
protocols that applications use to exchange data. There are
many Application layer protocols and new protocols are
always being developed.
• The most widely-known Application layer protocols are those
used for the exchange of user information:
• The Hypertext Transfer Protocol (HTTP) is used to transfer files
that make up the Web pages of the World Wide Web.
• The File Transfer Protocol (FTP) is used for interactive file
transfer.
• The Simple Mail Transfer Protocol (SMTP) is used for the
transfer of mail messages and attachments.

16. Application layer
• Telnet, a terminal emulation protocol, is used for logging on
remotely to network hosts.
• Additionally, the following Application layer protocols help
facilitate the use and management of TCP/IP networks:
• The Domain Name System (DNS) is used to resolve a host
name to an IP address.
• The Routing Information Protocol (RIP) is a routing protocol
that routers use to exchange routing information on an IP
internetwork.
• The Simple Network Management Protocol (SNMP) is used
between a network management console and network
devices (routers, bridges, intelligent hubs) to collect and
exchange network management information.

17. Operation of TCP and IP

18. TCP and UDP
TCP UDP
TCP is a connection-oriented protocol UDP is a connectionless protocol
There is absolute guarantee that the
data transferred remains intact and
arrives in the same order in which it
was sent
There is no guarantee that the
messages or packets sent would reach
at all
TCP is suited for applications that
require high reliability, and
transmission time is relatively less
critical
UDP is suitable for applications that
need fast, efficient transmission, such
as games. UDP's stateless nature is
also useful for servers that answer
small queries from huge numbers of
clients
HTTP, HTTPs, FTP, SMTP, Telnet DNS, DHCP, TFTP, SNMP, RIP, VOIP

19. TCP and UDP
TCP header size is 20 bytes UDP Header size is 8 bytes.
TCP is heavy-weight. TCP requires
three packets to set up a socket
connection, before any user data can
be sent. TCP handles reliability and
congestion control
UDP is lightweight. There is no
ordering of messages, no tracking
connections, etc. It is a small transport
layer designed on top of IP
TCP does error checking UDP does error checking, but no
recovery options.
1. Sequence Number, 2. AcK number,
3. Data offset, 4. Reserved, 5. Control
bit, 6. Window, 7. Urgent Pointer 8.
Options, 9. Padding, 10. Check Sum,
11. Source port, 12. Destination port
1. Length, 2. Source port, 3.
Destination port, 4. Check Sum
Acknowledgement segments No Acknowledgment

20. TCP and UDP

21. What is Internet Protocol (IP)?
• IP (short for Internet Protocol) specifies the technical format
of packets and the addressing scheme for computers to
communicate over a network. Most networks combine IP with
a higher-level protocol called Transmission Control Protocol
(TCP), which establishes a virtual connection between a
destination and a source
• IP by itself can be compared to something like the postal
system. It allows you to address a package and drop it in the
system, but there's no direct link between you and the
recipient
• TCP/IP, on the other hand, establishes a connection between
two hosts so that they can send messages back and forth for a
period of time

22. What is IPv4
• IPv4 (Internet Protocol Version 4) is the fourth revision of the
Internet Protocol (IP) used to to identify devices on a
network through an addressing system. The Internet Protocol
is designed for use in interconnected systems of packet-switched
computer communication networks
• Pv4 is the most widely deployed Internet protocol used to
connect devices to the Internet. IPv4 uses a 32-bitaddress
scheme allowing for a total of 2^32 addresses (just over 4
billion addresses)

23. What is IPv6
• Pv6 (Internet Protocol Version 6) is also called IPng
(Internet Protocol next generation) and it is the newest version
of the Internet Protocol (IP) reviewed in the IETF standards
committees to replace the current version of IPv4 (Internet
Protocol Version 4).
• IPv6 is the successor to Internet Protocol Version 4 (IPv4)
• IPv6 is designed to allow the Internet to grow steadily, both in
terms of the number of hosts connected and the total amount
of data traffic transmitted
•

24. The Difference Between IPv6 and IPv4 IP Addresses
• An IP address is binary numbers but can be stored as text for
human readers. For example, a 32-bit numeric address (IPv4)
is written in decimal as four numbers separated by periods
• Each number can be zero to 255
• For example, 1.160.10.240 could be an IP address
• IPv6 addresses are 128-bit IP address written in hexadecimal
and separated by colons
• An example IPv6 address could be written like
this: 3ffe:1900:4545:3:200:f8ff:fe21:67cf

25. IP and IPv6

26. IPv6