1. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 23 Congestion Control and Quality of Service

2. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.1 Data Traffic Traffic Descriptor Traffic Profiles

3. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.1 Traffic descriptors

4. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.2 Constant-bit-rate traffic

5. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.3 Variable-bit-rate traffic

6. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.4 Bursty traffic

7. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.2 Congestion Network Performance

8. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.5 Incoming packet

9. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.6 Packet delay and network load

10. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.7 Throughput versus network load

11. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.3 Congestion Control Open Loop Closed Loop

12. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.4 Two Examples Congestion Control in TCP Congestion Control in Frame Relay

13. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 TCP assumes that the cause of a lost segment is due to congestion in the network. Note:

14. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 If the cause of the lost segment is congestion, retransmission of the segment does not remove the cause—it aggravates it. Note:

15. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.8 Multiplicative decrease

16. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.9 BECN

17. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.10 FECN

18. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.11 Four cases of congestion

19. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.5 Quality of Service Flow Characteristics Flow Classes

20. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.6 Techniques to Improve QoS Scheduling Traffic Shaping Resource Reservation Admission Control

21. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.12 Flow characteristics

22. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.13 FIFO queue

23. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.14 Priority queuing

24. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.15 Weighted fair queuing

25. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.16 Leaky bucket

26. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.17 Leaky bucket implementation

27. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 A leaky bucket algorithm shapes bursty traffic into fixed-rate traffic by averaging the data rate. It may drop the packets if the bucket is full. Note:

28. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.18 Token bucket

29. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 The token bucket allows bursty traffic at a regulated maximum rate. Note:

30. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.7 Integrated Services Signaling Flow Specification Admission Service Classes RSVP

31. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Integrated Services is a flow-based QoS model designed for IP. Note:

32. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.19 Path messages

33. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.20 Resv messages

34. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.21 Reservation merging

35. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.22 Reservation styles

36. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.8 Differentiated Services An Alternative to Integrated Services

37. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Differentiated Services is a class-based QoS model designed for IP. Note:

38. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.23 DS field

39. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.24 Traffic conditioner

40. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 23.9 QoS in Switched Networks QoS in Frame Relay QoS in ATM

41. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.25 Relationship between traffic control attributes

42. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.26 User rate in relation to Bc and Bc + Be

43. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.27 Service classes

44. McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.28 Relationship of service classes to the total capacity