Computer Communication N_L03TCP_IPModel.pptx

TCP IP model

1. TCP/IP Model Dr. Ajay Singh Raghuvanshi Electronics & Telecommunication Engineering, NIT, Raipur

2. TCP/IP Protocol Suite Dr.Ajay Singh Raghuvanshi 2 1/20/2023 The layers in the TCP/IP protocol suite do not exactly match those in the OSI model . The original TCP/IP protocol suite was defined as having four layers: Host-to-Network , Internet , Transport , and Application . However, when TCP/IP is compared to OSI , we can say that the TCP/IP protocol suite is made of five layers : Physical , Data link , Network , Transport , and Application . The first four layers provide physical standards, network interface, internetworking, and transport functions that correspond to the first four layers of the OSI model . The three topmost layers in the OSI model, however, are represented in TCP/IP by a single layer called the Application layer .

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5. Dr.Ajay Singh Raghuvanshi 5 1/20/2023 Table 1. Differences between TCP, UDP, and SCTP Attribute TCP UDP SCTP Reliability Reliable Unreliable Reliable Connection Management Connection-oriented Connectionless Connection-oriented Transmission Byte-oriented Message-oriented Message-oriented Flow Control Yes No Yes Congestion Control Yes No Yes Fault Tolerance No No Yes Data Delivery Strictly Ordered Unordered Partially ordered Security Yes Yes Improved The following table highlights the general differences in behavior between SCTP and existing transport protocols, TCP and UDP. In general,  SCTP  may provide more flexibility for certain applications, like  Voice over IP (VoIP) , that require the reliable but message-oriented data

6. Dr.Ajay Singh Raghuvanshi 6 1/20/2023 Addresses in TCP/IP

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8. Dr.Ajay Singh Raghuvanshi 8 1/20/2023 A node with Physical address 10 sends a frame to a node with Physical address 87 . The two nodes are connected by a link. At the data link level this frame contains physical (link) addresses in the header. These are the only addresses needed. The rest of the header contains other information needed at this level. The trailer usually contains extra bits needed for error detection. most local area networks use a 48-bit (6 bytes) physical address(MAC) written as 12 hexadecimal digits, with every 2 bytes separated by a colon 07:01:02:01:2C:4B

9. Dr.Ajay Singh Raghuvanshi 9 1/20/2023 MAC Address Format

10. Dr.Ajay Singh Raghuvanshi 10 1/20/2023 we want to send data from a node with network address A and physical address 10 , located on one LAN , to a node with a network address P and physical address 95 , located on another LAN. Because the two devices are located on different networks, we cannot use link addresses only; the link addresses have only local jurisdiction . What we need here are universal addresses that can pass through the LAN boundaries. The network (logical) addresses have this characteristic.

11. Dr.Ajay Singh Raghuvanshi 11 1/20/2023 The packet at the network layer contains the logical addresses, which remain the same from the original source to the final destination ( A and P , respectively, in the figure). They will not change when we go from network to network. However, the physical addresses will change as the packet moves from one network to another. The boxes labeled routers are internetworking devices, which we will discussed later Internet address (in IPv4) is 32 bits in length, normally written as four decimal numbers, with each number representing 1 byte. The numbers are separated by a dot. 132.24.75.9

12. Dr.Ajay Singh Raghuvanshi 12 1/20/2023 Figure in the next slide shows two computers communicating via the Internet. The sending computer is running three processes at this time with port addresses a, b, and c. The receiving computer is running two processes at this time with port addresses j and k. Process a in the sending computer needs to communicate with process j in the receiving computer. Note that although physical addresses change from hop to hop, logical and port addresses remain the same from the source to destination. Example of Port Address

13. Dr.Ajay Singh Raghuvanshi 13 1/20/2023 A port address is a 16-bit address represented by one decimal number example 80

14. Some practically used port Addresses Dr.Ajay Singh Raghuvanshi 14 1/20/2023  123  Network Time Protocol (NTP)  UDP  135-139  NetBIOS  TCP and UDP  143  Internet Message Access Protocol (IMAP4)  TCP and UDP  161, 162  Simple Network Management Protocol (SNMP)  TCP and UDP  389  Lightweight Directory Access Protocol  TCP and UDP  443  HTTP with Secure Sockets Layer (SSL)  TCP and UDP  989, 990  FTP over SSL/TLS (implicit mode)  TCP  3389  Remote Desktop Protocol  TCP and UDP Port Service name Transport protocol  20, 21  File Transfer Protocol (FTP)  TCP  22  Secure Shell (SSH)  TCP and UDP  23  Telnet  TCP  25  Simple Mail Transfer Protocol (SMTP)  TCP  50, 51   IPSec    53  Domain Name System (DNS)  TCP and UDP  67, 68  Dynamic Host Configuration Protocol (DHCP)  UDP  69  Trivial File Transfer Protocol (TFTP)  UDP  80  HyperText Transfer Protocol (HTTP)  TCP  110  Post Office Protocol (POP3)  TCP

15. Dr.Ajay Singh Raghuvanshi 15 1/20/2023 HTTP Request TCP Header Header contains source and destination port numbers Header contains source and destination IP addresses; transport protocol type IP Header Header contains source and destination physical addresses; network protocol type Frame Check Sequence Ethernet Header

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17. Assignment –II DOS: 6/02/2022 Tabulate the developed OSI 7 layered protocols with name, layer, purpose and its application. Tabulate the developed TCP/IP layered model protocols with name, layer, purpose and its application. Dr.Ajay Singh Raghuvanshi 17 1/20/2023