tailieunhanh - Network Fundamentals – Chapter 4

OSI Transport Layer. In this chapter, we examine the role of the Transport layer. The Transport layer also encompasses these functions: Enables multiple applications to communicate over the network at the same time on a single device. Ensures that, if required, all the data is received reliably and in order by the correct application. Employs error handling mechanisms. Learning Objectives–Upon completion of this chapter, you will be able to: Explain the need for the Transport layer. Identify the role of the Transport layer as it provides the end-to-end transfer of data between applications. . | 111 a 111 a CISCO OSI Transport Layer Network Fundamentals - Chapter 4 2006 Cisco Systems Inc. All rights reserved. Cisco Public 1 Objectives In this chapter we examine the role of the Transport layer. The Transport layer also encompasses these functions - Enables multiple applications to communicate over the network at the same time on a single device - Ensures that if required all the data is received reliably and in order by the correct application - Employs error handling mechanisms Learning Objectives - Upon completion of this chapter you will be able to - Explain the need for the Transport layer. - Identify the role of the Transport layer as it provides the end-to-end transfer of data between applications. - Describe the role of two TCP IP Transport layer protocols TCP and UDP. - Explain the key functions of the Transport layer including reliability port addressing and segmentation. - Explain how TCP and UDP each handle key functions. - Identify when it is appropriate to use TCP or UDP and provide examples of applications that use each protocol. 2006 Cisco Systems Inc. All rights reserved. Cisco Public 2 Purpose of the Transport Layer The Transport layer provides for the segmentation of data necessary to reassemble these pieces into the various communication streams. Its primary responsibilities to accomplish this are -Tracking the individual communication between applications on the source and destination hosts Any host may have multiple applications that are communicating across the network. It is the responsibility of the Transport layer to maintain the multiple communication streams between these applications. -Segmenting data and managing each piece The Transport layer protocols describe services that segment this data from the Application layer. Each piece of application data requires headers at the Transport layer to indicate to which communication it is associated. -Reassembling the segments into application data At the receiving host these .