tcp.pptx
- 2. INTRODUCTION -concentrate on the transport protocols i -figure on next slide shows the position of three protocols in the TCP/IP protocol suite.
- 3. Position of transport-layer protocols in the TCP/IP protocol suite
- 4. Services Each protocol provides a different type of service and should be used appropriately. 24.4
- 5. Port Numbers - Port numbers provide end-to-end addresses at the transport layer - allow multiplexing and demultiplexing, just as IP addresses do at the network layer - Table gives some common port numbers
- 6. Some well-known ports used with UDP and TCP
- 7. UDP The User Datagram Protocol (UDP) is - a connectionless, unreliable transport protocol - UDP is a very simple protocol using a minimum of overhead.
- 8. User Datagram - UDP packets, called user datagrams, have a fixed-size header of 8 bytes made of four fields, each of 2 bytes (16 bits) - Figure shows the format of a user datagram - The first two fields define the source and destination port numbers. - The third field defines the total length of the user datagram, header plus data - The last field can carry the checksum
- 9. User datagram packet format
- 10. TCP - is a connection-oriented - reliable protocol - explicitly defines connection establishment, data transfer, and connection teardown phases - uses a combination of GBN and SR protocols to provide reliability
- 12. Sending and receiving buffers Stream of bytes Sending process Receiving process
- 15. Control field
- 16. Connection establishment using three-way handshaking
- 18. Connection termination using three-way handshaking 24.18
- 19. Flow Control - Flow control balances the rate a producer creates data with the rate a consumer can use the data - We assume that the logical channel between the sending and receiving TCP is error-free.
- 20. Data flow and flow control feedbacks in TCP
- 21. An example of flow control
- 22. Error Control TCP is a reliable transport-layer protocol This means that an application program that delivers a stream of data to TCP relies on TCP to deliver the entire stream to the application program on the other end in order, without error, and without any part lost or duplicated.
- 23. Normal operation
- 24. Lost segment
- 26. Lost acknowledgment corrected by resending a segment
- 27. TCP Congestion Control TCP uses different policies to handle the congestion in the network. We describe these policies in this section.
- 28. Slow start, exponential increase
- 29. Congestion avoidance, additive increase
- 30. Example of Taho TCP 24.30
- 31. Example of a Reno TCP 24.31
- 32. Additive increase, multiplicative decrease (AIMD) 24.32