The transport layer segments application data, establishes end-to-end operations between hosts, and ensures reliable data transfer through the use of sequence numbers, acknowledgments, and flow control with sliding windows. It uses protocols like TCP and UDP, with TCP providing reliable connections using acknowledgments and UDP providing unreliable but connectionless delivery.

2. Purpose of the Transport Layer
 Segmenting upper-layer application data.
 Establishing end-to-end operations.
 Sending segments from one end host to another end host.
 Ensuring flow control provided by sliding windows.
 Ensuring reliability provided by sequence numbers and
acknowledgments.

3. Segmentation

4. Transport Layer Protocols

5. TCP and UDP
Physical
Data link
Network
Transport
TCP UDP
Builds Connections
Uses Sequence Numbers
Reliable (Uses ACKs)
Connectionless
Best-Effort Delivery
Unreliable
TCP or UDP
IP Addresses
MAC Addresses

6. How TCP and UDP Work

7. More on TCP Communication

8. TCP Windowing

9. TCP Windowing

10. TCP Windowing

11. Port Numbers

12. Port Numbers