TAILIEUCHUNG - Bài giảng Chapter 5: Transport Layer UDP and TCP

Chapter 5: Transport Layer UDP and TCP. Overview of Transport Layer, UDP Protocol, UDP Protocol, types of data deliveries, port numbers, IP addresses versus port numbers, IANA ranges, socket, address, Multiplexing and demultiplexing, error control, position of UDP, TCP, and SCTP in TCP/IP suite. | Chapter 5 Transport Layer: UDP and TCP Outline Overview of Transport Layer UDP Protocol TCP Protocol PROCESS-TO-PROCESS DELIVERY The transport layer is responsible for process-to-process delivery—the delivery of a packet, part of a message, from one process to another. Two processes communicate in a client/server relationship, as we will see later. The transport layer is responsible for process-to-process delivery. Note The transport layer tasks include: Note Types of data deliveries Port numbers IP addresses versus port numbers IANA ranges Socket address Multiplexing and demultiplexing Error control Position of UDP, TCP, and SCTP in TCP/IP suite USER DATAGRAM PROTOCOL (UDP) The User Datagram Protocol (UDP) is called a connectionless, unreliable transport protocol. It does not add anything to the services of IP except to provide process-to-process communication instead of host-to-host communication. Well-Known Ports for UDP User Datagram Checksum UDP Operation Use of UDP Topics discussed in this section: Well-known ports used with UDP In UNIX, the well-known ports are stored in a file called /etc/services. Each line in this file gives the name of the server and the well-known port number. We can use the grep utility to extract the line corresponding to the desired application. The following shows the port for FTP. Note that FTP can use port 21 with either UDP or TCP. Example Example (continued) SNMP uses two port numbers (161 and 162), each for a different purpose, as we will see in Chapter 28. User datagram format UDP length = IP length – IP header’s length Note Pseudoheader for checksum calculation Figure 11 shows the checksum calculation for a very small user datagram with only 7 bytes of data. Because the number of bytes of data is odd, padding is added for checksum calculation. The pseudoheader as well as the padding will be dropped when the user datagram is delivered to IP. Example Checksum calculation of a simple UDP user datagram Queues in UDP TCP TCP

• Cơ sở dữ liệu
• Transport Layer UDP and TCP
• Overview of Transport Layer
• Types of data deliveries
• Port numbers
• Multiplexing and demultiplexing
• Process to Process Delivery
• UDP
• TCP
• SCTP
• transport layer