TCP/IP

• Yang Wang

• 103301

• Professor: M.ANVARI

TCP/IP

• 1: Distributed Processing• 2: Communications Architecture• 3: What is TCP/IP• 4: TCP/IP Architecture Model • 5: TCP• 6: IP• 7: The Operation of the TCP/IP

• 8: Conclusion

Distributed Processing

• 1: Centralized data processing: Mainframe, Host, Terminal. Only host processes data.

• 2: Distributed data processing: LAN, Sever, Workstation. Workstation fetches software from Sever, and processes data by itself.

• 3: The advantage of DDP include:

• 1): Responsiveness

• 2): Availability

• 3): Resource sharing

• 4): Incremental growth

• 5): Increased user involvement and control

• 6): End-user productivity

Communications Architecture

• 1: To achieve these DDP benefits, the operation system must provide a range of support functions for DDP. These include the software for exchanging data among workstations.

• 2: Communication Architecture is software that supports a network of independent computer.

• 3: It is possible that each computer has its own separate and different operation system, as long as all computers support the same communications architecture.

• 4: The technology of the communications architecture is well developed and is supported by all vendors. TCP/IP is the most widely used communications architecture protocol suite.

What is TCP/IP?(con)

• 1: TCP/IP stands for Transmission Control Protocol/Internet Protocol. It is a networking protocol that provides communication across interconnected networks, between computers with diverse hardware architectures and various operating systems.

• 2: It was developed by a Department of Defense (DOD) research project to connect a number of different networks designed by different venders into a network of the Internet.

• 3: The most important TCP/IP services are:• 1): File transfer. The file transfer protocol (FTP) allows a user on any

computer to get files from another computer, or to send files to another computer.

What is TCP/IP?(2)

• 2): Electronic mail. Simple Mail Transfer Protocol (SMTP) to send electronic mail on a TCP/IP network. This allows you to send messages to users on other computers.

• 3): Remote login. The Network Terminal Protocol (TELNET) allows a user to log in on any other computer on the network.

• 4: Why is the TCP/IP popular?• 1): Robust client-server framework. It is an excellent client-server

application platform, especially in wide-area network environment.

• 2): Information sharing. Thousands of academic, defense, scientific, and commercial organizations share data, electronic mail and services on the connected Internet using TCP/IP.

What is TCP/IP?(3)

• 3): General availability. Implementations of TCP/IP are available on nearly every popular computer operating system.Additionally, bridge, router and network analyzer vendors all offer support for the TCP/IP protocol family within their products.

TCP/IP Architecture Model

• 1: Application layer. This layer contains the logic need to support the various user applications.

• 2: Transport layer or Host-to-host layer. This layer handles all error detection and recovery. Reliability control is concentrated at this layer by Using checksums, acknowledgments, and time-outs.

• 3: Internet layer. The IP is used at this layer to provide the routing function across multiple networks.

• 4: Subnet layer. Covers the physical interface and the exchange of data between an end system and the network to which it is attached.

TCP(con)

• 1: Definition• 1): TCP is a transport layer, connection-oriented, end-to-end protocol.

It provides reliable, sequenced, and unduplicated delivery of bytes to a remote or local user.

• a): Connection-oriented implies that TCP first establishes a connection between the two systems that intend to exchange data.

• b): End-to-end means data transmission between the source system and the destination system.

• 2): Datagram: A transmission method in which sections of a message are transmitted in scattered order and the correct order is re-established by the receiving workstation. TCP/IP supports Datagram. So no two communicating computers monopolize the network.

TCP(2)

• 2: How TCP works?• 1): Sequence number

• a): when an application sends a message to TCP for transmission, TCP breaks the message into packets, and sized appropriately for the network.

• b): TCP marks these packets with sequence numbers before sending them.

• c): The sequence numbers allow the receiving system to properly reassemble the original message.

TCP(3)

• 2): Checksum• a): Being able to reassemble the original message is not enough, the

accuracy of the data must also be verified. TCP does this by computing a checksum.

• b): A checksum is a simple mathematical computation applied, by the sender, to the data contained in the TCP packet.

• c): The recipient then does the same calculation on the received data and compares the result with the checksum that the sender computed.

• d): If the results match, the recipient sends an acknowledgment (ACK). If the results do not match, the recipient asks the sender to resend the packet.

TCP(4)

• 3): The port ID: TCP uses port ID to specify which application running on the system is sending or receiving data.

• 4): The TCP header:

• a):The port ID, sequence number, and checksum are inserted into the TCP packet in a special section called the header.

• b): The header is at the beginning of the packet containing this and other “control” information for TCP.

IP(con)

• 1: Definition • IP is the messenger protocol of TCP/IP. The IP protocol, much simpler

than TCP, basically addresses and sends packets

• 2: How IP works? • 1): IP relies on three pieces of information, which you provide, to

receive and deliver packets successfully: IP address, subnet mask, and default gateway..

IP(2)

• 2): IP address• a): The IP address identifies your system on the TCP/IP network.

• b): IP addresses are 32-bit addresses that are globally unique on a network

• c): They are generally represented in dotted decimal notation, which separates the four bytes of the address with periods. An IP address looks like this: 102.54.94.97

• d): Although an IP address is a single value, it really contains two pieces of information: your system’s network ID and your system’s host ID.

IP(3)

• 3): the subnet mask• a): It also represented in dotted decimal notation, is used to extract the

network ID and host ID from your IP address.

• b): the value of the subnet mask is determined by setting the network ID bits of the IP address to ones and the host ID bits to zeros.

• c): It allows TCP/IP to determine the host ID and network ID of the workstation.

• d): example: when the IP address is 102.54.94.97 ( specified by the user ) and the subnet mask is 255.255.0.0 (specified by the user ) The network ID is 102.54 ( IP address and subnet mask ) and the host ID is 94.97 ( IP address and subnet mask )

The Operation of the TCP/IP

• 1: The sending process generates a block of data and passes this to the TCP layer.

• 2: TCP may break this block into packets and append the TCP header, then hands each packet over to the IP layer.

• 3: IP appends an IP header to each packet then presents it to the subnet layer.

• 4: the subnet layer appends its own header to each packet, then sends it to the receiver across the sub-networks.

• 5: when recipient receives data, the reverse process occurs. At each layer , the corresponding header is removed, until the original user data are delivered to the destination process.

conclusion

• 1: TCP/IP is the most complete and accepted networking protocol available

• 2: Almost all modern operating systems offer TCP/IP support, and most large networks rely on TCP/IP for all their network traffic.