1 Module 01 InterNetwork Overview Chapter 07 Fundamentals of TCP and UDP 2 Table of Content 1 Typical features of layer 4 2 The Transmission Control Protocol 3 The User Datagram Protocol 3 1. Typical Features of OSI Layer 4 4 Introduction to transport layer  The primary duties of the transport layer are to transport and regulate the flow of information from the source to the destination, reliably and accurately.  The transport layer defines end-to-end connectivity between host applications  Transport services include the following basic services:  Segmentation of upper-layer application data  Establishment of end-to-end operations  Transport of segments from one end host to another end host  Flow control provided by sliding windows  Reliability provided by sequence numbers and acknowledgments 5 2. The Transmission Control Protocol 6 TCP: Three way handshaking A B 7 TCP: Window and Acknowledgment 8 TCP: Sliding window and Acknowledgment 9 TCP: Sequence and acknowledgment 1 0 Transport Layer: TCP  TCP supplies a reliably transportation between end-user applications.  These are its characteristics:  Connection-oriented.  Supplies a virtual circuit between end-user applications  Breacking outgoing messages into segments and reassembles messages at the destination.  Resends anything not received by acknowledgement.  Flow control: Windowing.  The protocols that use TCP include: FTP, HTTP SMTP, Telnet. [...]... software checking for message delivery  Transmit messages, does not need reassemble incoming messages  Without acknowledgements  Error processing and retransmission must be handled by higher layer protocols  The protocols that use UDP include: TFTP, SNMP, DHCP, DNS UDP Header format 68 -7 FC R  UDP is a simple protocol that exchanges datagrams, without acknowledgments or guaranteed delivery TCP. .. simple protocol that exchanges datagrams, without acknowledgments or guaranteed delivery TCP and UDP port numbers 00 -1 7 FC R  Both TCP and UDP use port (or socket) numbers to pass information to the upper layers Range of ports  2 bytes: 0 – 65535  Numbers below 255 : for public applications  Numbers from 255 - 1023 : assigned to companies for marketable applications  Numbers above 1023 : are unregulated... data from sender TCP Header format: Window •• Window: 16 bits Window: 16 bits – The number of data octets beginning – The number of data octets beginning with the one indicated in the with the one indicated in the acknowledgment field which the sender acknowledgment field which the sender of this segment is willing to accept of this segment is willing to accept Transport Layer: UDP  UDP transports... is present) (except when SYN is present) TCP Header format: Acknowledgment •• Acknowledgment Number: 32 bits Acknowledgment Number: 32 bits – This field contains the value of the – This field contains the value of the next sequence number the sender of next sequence number the sender of the segment is expecting to receive the segment is expecting to receive TCP Header format: Code bits •• Control Bits:.. .TCP Header format 61 -7 FC R TCP Header format: Port number •• •• Source Port 16 bits Source Port 16 bits Destination Port 16 bits Destination Port 16 bits TCP Header format: Sequence •• Sequence Number: 32 bits Sequence Number: 32 bits – The sequence number of the – The sequence number of the first data octet in this segment first data octet... number larger than 1023 Telnet port number Summary  TCP:  Connection-oriented  Supplies a virtual circuit between end-user applications  Breacking outgoing messages into segments and reassembles messages at the destination  Resends anything not received by acknowledgement  Flow control: Windowing  UDP:  Connectionless  Unreliable, no software checking for message delivery  Transmit messages,... UDP:  Connectionless  Unreliable, no software checking for message delivery  Transmit messages, does not need reassemble incoming messages  Without acknowledgements  Error processing and retransmission must be handled by higher layer protocols . 1 Module 01 InterNetwork Overview Chapter 07 Fundamentals of TCP and UDP 2 Table of Content 1 Typical features of layer 4 2 The Transmission Control Protocol 3 The. Protocol 6 TCP: Three way handshaking A B 7 TCP: Window and Acknowledgment 8 TCP: Sliding window and Acknowledgment 9 TCP: Sequence and acknowledgment 1 0 Transport Layer: TCP  TCP supplies. delivery. R F C - 7 6 8 R F C - 7 6 8 1 9 TCP and UDP port numbers  Both TCP and UDP use port (or socket) numbers to pass information to the upper layers. R F C - 1 7 0 0 R F C - 1 7 0 0 2 0 Range of ports  2 bytes: