The Transport layer segments and reassembles data into a data stream. Services located in the Transport layer both segment and reassemble data from upper-layer applications and unite it onto the same data stream. They provide end-to-end data transport services and can establish a logical connection between the sending host and destination host on an internetwork.
Some of you are probably familiar with TCP and UDP already. (But if you’re not, no worries— I’ll tell you all about them in Chapter 2, “Internet Protocols.”) If so, you know that both work at the Transport layer, and that TCP is a reliable service and UDP is not. This means that application developers have more options because they have a choice between the two protocols when working with TCP/IP protocols.
The Transport layer is responsible for providing mechanisms for multiplexing upper-layer applications, establishing sessions, and tearing down virtual circuits. It also hides details of any network-dependent information from the higher layers by providing transparent data transfer.
Some of you are probably familiar with TCP and UDP already. (But if you’re not, no worries— I’ll tell you all about them in Chapter 2, “Internet Protocols.”) If so, you know that both work at the Transport layer, and that TCP is a reliable service and UDP is not. This means that application developers have more options because they have a choice between the two protocols when working with TCP/IP protocols.
The Transport layer is responsible for providing mechanisms for multiplexing upper-layer applications, establishing sessions, and tearing down virtual circuits. It also hides details of any network-dependent information from the higher layers by providing transparent data transfer.