tailieunhanh - Network Fundamentals–Chapter 3

Application Layer Functionality and Protocols. In this chapter, you will learn to: Describe how the functions of the three upper OSI model layers provide network services to end user applications. Describe how the TCP/IP Application Layer protocols provide the services specified by the upper layers of the OSI model. Define how people use the Application Layer to communicate across the information network. Describe the function of well-known TCP/IP applications, such as the World Wide Web and email, and their related services (HTTP, DNS, SMB, DHCP, SMTP/POP, and Telnet) | 111 a 111 a CISCO Application Layer Functionality and Protocols Network Fundamentals - Chapter 3 ITE I Chapter 6 2006 Cisco Systems Inc. All rights reserved. Cisco Public 1 Objectives In this chapter you will learn to - Describe how the functions of the three upper OSI model layers provide network services to end user applications. - Describe how the TCP IP Application Layer protocols provide the services specified by the upper layers of the OSI model. - Define how people use the Application Layer to communicate across the information network. - Describe the function of well-known TCP IP applications such as the World Wide Web and email and their related services HTTP DNS SMB DHCP SMTP POP and Telnet . - Describe file-sharing processes that use peer-to-peer applications and the Gnutella protocol. - Explain how protocols ensure services running on one kind of device can send to and receive data from many different network devices. - Use network analysis tools to examine and explain how common user applications work. ITE 1 Chapter 6 2006 Cisco Systems Inc. All rights reserved. Cisco Public 2 OSI and TCP IP Model The Open Systems Interconnection reference model is a layered abstract representation created as a guideline for network protocol design. -The OSI model divides the networking process into 7 logical layers each of which has unique functionality and to which are assigned specific services and protocols. In the OSI model information is passed from one layer to the next starting at the Application layer down the hierarchy to the Physical layer then passing over the communications channel to the destination host where the information proceeds back up the hierarchy ending at the Application layer. ITE 1 Chapter 6 The Human Network Generates Data App icaton layer services Initiate the data Application layer services 7 Appt cation Software and And. the Application layer receives data from the network and prepares II for human use 3 2006 Cisco Systems Inc. All .