1. www.ciscopress.com Copyright 2003 CCNA 1 Chapter 9 TCP/IP Transport and Application Layers By Your Name

2. www.ciscopress.com Copyright 2003 Objectives TCP/IP transport layer TCP/IP application layer

3. www.ciscopress.com Copyright 2003 Routed Protocols Versus Routing Protocols Routing protocols determine the path that routed protocols follow to their destinations.

4. www.ciscopress.com Copyright 2003 The Transport Layer Functions Five basic services: Segmenting upper-layer application data Establishing end-to-end operations Sending segments from one end host to another end host Ensuring data reliability Providing flow control

5. www.ciscopress.com Copyright 2003 Flow Control Avoids the problem of a host at one side of the connection overflowing the buffers in the host at the other side Ensures the integrity of the data

6. www.ciscopress.com Copyright 2003 Session Establishment

7. www.ciscopress.com Copyright 2003 Three-Way Handshake

8. www.ciscopress.com Copyright 2003 Windowing A method of controlling the amount of information transferred end to end Information can be measured in terms of the number of packets or the number of bytes

9. www.ciscopress.com Copyright 2003 Window Size Larger window sizes increase communication efficiency.

10. www.ciscopress.com Copyright 2003 Acknowledgment Positive acknowledgment requires a recipient to communicate with the source, sending back an acknowledgment message when it receives data. Sender keeps a record of each data packet that it sends and expects an acknowledgment.

11. www.ciscopress.com Copyright 2003 Layer 4 Protocols

12. www.ciscopress.com Copyright 2003 TCP Connection oriented Reliable Divides outgoing messages into segments Reassembles messages at the destination station Resends anything not received Reassembles messages from incoming segments

13. www.ciscopress.com Copyright 2003 UDP Connectionless Unreliable Transmits messages (called user datagrams) Provides no software checking for message delivery (unreliable) Does not reassemble incoming messages Uses no acknowledgments Provides no flow control

14. www.ciscopress.com Copyright 2003 TCP/IP Protocol Graph

15. www.ciscopress.com Copyright 2003 TCP Segment Format

16. www.ciscopress.com Copyright 2003 UDP Segment Format

17. www.ciscopress.com Copyright 2003 Port Numbers

18. www.ciscopress.com Copyright 2003 Application Layer

19. www.ciscopress.com Copyright 2003 TCP/IP Application Layer

20. www.ciscopress.com Copyright 2003 Responsibilities Identifying and establishing the availability of intended communication partners Synchronizing cooperating applications Establishing agreement on procedures for error recovery Controlling data integrity

21. www.ciscopress.com Copyright 2003 Application Layer Examples Domain Name System File Transfer Protocol Hypertext Transfer Protocol Simple Mail Transport Protocol Simple Network Management Protocol Telnet

22. www.ciscopress.com Copyright 2003 Domain Name System

23. www.ciscopress.com Copyright 2003 FTP FTP is a reliable, connection-oriented service that uses TCP to transfer files between systems that support FTP.

24. www.ciscopress.com Copyright 2003 HTTP

25. www.ciscopress.com Copyright 2003 SMTP E-mail servers communicate with each other using the Simple Mail Transport Protocol (SMTP) to send and receive mail.

26. www.ciscopress.com Copyright 2003 SNMP The Simple Network Management Protocol (SNMP) is an application layer protocol that facilitates the exchange of management information between network devices. An SNMP managed network consists of the following: –Network management system (NMS) –Managed device –Agents

27. www.ciscopress.com Copyright 2003 Telnet Telnet client software provides the ability to log in to a remote Internet host that is running a Telnet server application and then to execute commands from the command line.