1. TCP/IP
Yang Wang
103301
Professor: M.ANVARI

2. TCP/IP 8: Conclusion 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

3. 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

4. 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.

5. 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.

6. What is TCP/IP?(2) 4: Why is the TCP/IP popular?
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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.

12. 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.

13. IP(con) 1: Definition 2: How IP works?
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..

14. 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:
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.

15. 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 ( specified by the user ) and the subnet mask is (specified by the user ) The network ID is ( IP address and subnet mask ) and the host ID is ( IP address and subnet mask )

16. 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.

17. 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.