The transport layer provides transport services from the source host to the destination host. The transport layer constitutes a logical connection between the endpoints of the network, the sending host and the receiving host. Transport protocols segment and reassemble upper-layer applications into the same data stream between endpoints. The transport layer data stream provides end-to-end transport services.

The Internet is often represented by a cloud. The transport layer sends data packets from the sending source to the receiving destination through the cloud. End-to-end control, provided by sliding windows and reliability in sequencing numbers and acknowledgments, is the primary duty of the transport layer when using TCP. The transport layer also defines end-to-end connectivity between host applications. Transport services include all the following services:

TCP and UDP

• Segmenting upper-layer application data
• Sending segments from one end device to another end device

TCP only

• Establishing end-to-end operations
• Flow control provided by sliding windows
• Reliability provided by sequence numbers and acknowledgments

The Internet is often represented by a cloud. The transport layer sends data packets from the sending source to the receiving destination through the cloud. The cloud deals with issues such as “Which of several paths is best for a given route?”

Interactive Media Activity Checkbox: The Transport Layer After completing this activity, the student will be able to identify the protocols used in the transport layer.

   

Web Links Transport Layer http://searchnetworking.techtarget.com/ sDefinition/0,,sid7_ gci213212,00.html