TCPIP

1
TCP/IP

• Transmission Control Protocol /
• Internet Protocol

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Background Information

• First developed by Department of Defense
  Research Project Agency (DARPA)
• It is really a suite of protocols also known as
  The Internet Suite of Protocols
• Because the TCP/IP are the main aspects of the
  suite It is called TCP/IP
• Currently IPv4 is used, IPv6 is developing
• It is available on EVERY PC, and it is the
  standard used for access to the internet.
• Other protocols are IPX/SPX, NetBIOS and
  AppleTalk.
• TCP/IP is the standard.

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What is a Protocol?

• Set of rules and guidelines that govern the
  communication between different devices.
• Basically they are specific rules for
  transferring information.
• The Internet is governed by rules set by TCP/IP
  or the Internet Suite of Protocols
• It is not just One Protocol, but many.
• These protocols are organized into a family that
  governs the Internet.

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The TCP/IP Layer

• The protocols can be divided into FOUR LAYERS
• Application Layer
• Provides application access to the network
• Transport Layer
• Provides flow control, sequencing, error checking
• Internet Layer
• Provides routing
• Network Interface
• Deals with the physical network connection

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The suite of Protocols for TCP/IP

• Each layer of TCP/IP consists of the protocols
  that are associated with that Layer
• These protocols each have a specific function
  that ensures the internet is used correctly and
  efficiently

Soruce http//burks.brighton.ac.uk/burks/pcinfo/h
ardware/ethernet/tcpip.htm
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The Core Protocols of TCP/IP

• Now, the Transmission Control Protocol (TCP) and
  the Internet Protocol (IP) are the main protocols
  that make up the TCP/IP Layer or the Internet
  Suite of Protocols.
• The Transmission Control Protocol (TCP) operates
  in the Transport Layer
• The Internet Protocol (IP) operates in the
  Internet Layer

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Internet Protocol (IP)

• Provides information about how and where packets
  should be delivered
• Enables the TCP/IP to inter-network
• It is connectionless protocol, therefore it does
  not guarantee delivery of data.
• It basically contains addressing information that
  allows packets to be routed
• It provides routing to the enterprise network
  then to the regional networks then to the
  internet
• A 32 bit IP address which consists of the network
  number and the host number. i.e. Four decimals
  separated by periods. E.g.
• 200.1.2.3

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What is a Packet?

• Everything on the internet involves a packet.
• Example
• Each website loaded comes as a series of packets
• Emails are sent as series of packets
• Sending an Email
• The network breaks the email into parts of a
  certain size in bytes the packets
• Each packet contains info that will help it get
  to its destination
• Then the packets carry the data
• Each packet contains part of the body of the
  message.

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Packet Information

• This is a simple example of an Email that will be
  sent via TCP / IP.
• The Total Length of the bytes will be stored and
  it will be sent until the entire packet has been
  received.

Sourcehttp//computer.howstuffworks.com/question5
25.htm
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Transmission Control Protocol (TCP)

• It is connection oriented, therefore a connection
  must be established between communicating nodes..
• Responsible for formatting packets and
  distributing them between networks
• Provides the following features
• Error Checking of Packets
• Data flow control
• Acknowledgement of Receiving Packets
• In the event that it does not need a connection
  it would use UDP.

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How you get a web-page..

• It is too much work to type an IP Address
• Therefore DNS Domain Name Serves allows names
  instead
• A Call out to a DNS server is done asking for the
  IP Address
• The DNS Sever replies with the IP Address
• TCP/IP makes the connection to the requested
  server using the IP Address

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How they work together

• If an application relied only on the Internet
  Protocol to transmit data, IP would sent packets
  without checking to see if the destination is
  online or if it was sent without errors
• TCP takes care of the communication between the
  application software such as Internet Explorer
  and the network Software
• IP takes care of the communication with other
  computers
• TCP is responsible for making sure that packets
  get to the other end in the correct order and if
  messages are too long (e.g. email) they are split
  up and sent in the correct order

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How they work together Contd

• TCP then calls on the services of the IP to
  actually get it to the destination
• TCP sends each of the packets to the IP. It tells
  the IP the IP address of the computer at the
  other end.
• Then IP finds a route for the packet to get to
  the other end.

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Sub - Protocols of TCP/IP

• UDP User Datagram Protocol
• A connectionless transport service, offers no
  assurance that packets will be received in the
  correct sequence, and no error checking
  provision, however it is more efficient and there
  is no overhead when sending audio and video
  transmission over the internet, and hence it is
  sent quickly
• ARP Address Resolution Protocol
• Works very close with the IP. It obtains the MAC
  address of the host, then creates a local dbase
  that maps it to the hosts IP address. The IP
  needs to know the address of a destination before
  it can direct data to it.
• ICMP Internet Control Message Protocol
• Notifies the sender when something goes wrong in
  the transmission of a packet and the packets are
  not delivered.

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Sub- Protocols of TCP/IP

• FTP File Transfer Protocol
• transfer of web page files between computers and
  downloading application programs other files
  from servers
• SMPT Simple Mail Transport Protocol
• Governs the transfer of electronic mail e-mails
  over the internet
• HTTP Hyper Text Transfer Protocol
• Lets users access interconnected web pages and
  related files on the net
• POP3 Post Office Protocol
• Controls the storage of emails on the server.

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Comparing TCP/IP with the OSI Model

• The Application Layer is Equivalent to the
  Application Presentation Session Layer of the
  OSI Modelbecause applications gain access to the
  network via this layer.
• The Transport Layer is equivalent to the
  Transport Layer of the OSI which provides flow
  control, error checking etc.
• Internet Layer is equivalent to the Network Layer
  of the OSI handles message routing etc.
• Network Interface handles the formatting of
  data and transmission

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Comparing IPX / SPX with TCP/IP

• IPX Inter-network Packet eXchange
• Provides routing and inter-network services
  similar to the IP of TCP/IP
• It is a connectionless service it does not
  guarantee that the data will be delivered in
  sequence or without errors
• It is efficient but it has limited capabilities
• Uses IPX Addresses, 8 bit Hexadecimal Numbers
  range from 0-9 A-F

• SPX Sequenced Packet eXchange
• Works with the IPX to ensure that the data is
  received correctly and in the right sequence
• Connection oriented
• If a packet has not been entirely received it
  will detect it and resend again.

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Comparing IPX/SPX with the OSI Model

• Implements the session, transport and network OSI
  Layers
• IPX manages packet routing and formatting
• SPX guarantees delivery of the packets by
  receiving acknowledgements of each packet.

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Summary and Conclusion

• TCP/IP is not only one protocol it is really a
  family of related protocols that govern how the
  internet is used.
• The Transmission Control Protocol (TCP) and the
  Internet Protocol (IP) are the main protocols in
  the suite.
• Transmission Control Protocol (TCP) basically
  ensures that the packets get to their destination
  in the correct sequence and without errors.
• Internet Protocol (IP) basically uses IP
  Addressing to forward these packets sent by the
  TCP to the correct computer.
• The other protocols such as the FTP, HTTP, SMTP
  are other protocols used to provide different
  services for the internet such as email,
  accessing websites, downloading files etc.
• TCP/IP corresponds with the layers of the OSI
  Model
• IPX/SPX another protocol is similar to the TCP/IP
  however TCP/IP is the standard and IPX/SPX is
  used with Novell Networks
• IPv6 is currently under development.