© 2005 Cisco Systems, Inc. All rights reserved.INTRO v2.16-1 Ensuring the Reliability of Data Delivery Understanding How UDP and TCP Work. - презентация

1 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Ensuring the Reliability of Data Delivery Understanding How UDP and TCP Work

2 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Outline Overview Transport Layer Functions Reliable vs. Best Effort UDP and TCP UDP and TCP Port Numbers UDP and TCP Header Formats Summary

3 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Transport Layer Session multiplexing Segmentation Flow control (when required) Connection-oriented (when required) Reliability (when required)

4 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Reliable vs. Best Effort Comparison

5 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v TCP/IP Protocol Stack

6 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v UDP Characteristics

7 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v TCP Characteristics

8 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Port Numbers

9 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v UDP Header

10 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v TCP Header

11 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Summary The transport layer operates between the network layer and the application layer and provides communication services directly to the application processes running on different hosts. UDP is a best-effort, connectionless protocol used for applications that do not require error checking or sequence numbering, such as voice and video streaming. TCP is a reliable, connection-oriented protocol that ensures delivery of packets without error and in correct order.

12 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v Summary (Cont.) UDP and TCP use ports to support multiple conversations between different network devices. UDP delivers TFTP, SNMP, and RIP. TCP delivers FTP, Telnet, and SMTP. The UDP header length is always 64 bits. The TCP header follows the Internet header, supplying information specific to the TCP protocol. This division allows for the existence of host-level protocols other than TCP.

13 © 2005 Cisco Systems, Inc. All rights reserved.INTRO v