PROTOCOL ARCHITECTURE,TCP/IP, 
AND INTERNET-BASED APPLICATIONS 
Ayyaz Yaqoob (Lecturer) 
Department of Computer Science 
UOS Mandi Bahauddin Campus
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
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
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
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
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
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
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
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
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
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
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.
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.
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
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.
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.
Operation of TCP and IP
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
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
TCP and UDP
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
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)
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 
•
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
IP and IPv6
IPv6

TCP/IP Protocols

  • 1.
    PROTOCOL ARCHITECTURE,TCP/IP, ANDINTERNET-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 FORA 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 FORA 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 PROTOCOLARCHITECTURE • 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 ofTCP/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 transportlayer • 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 transportlayer • 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.
  • 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.
  • 21.
    What is InternetProtocol (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 BetweenIPv6 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.
  • 26.