1 / 46

Chapter 23

Chapter 23. Congestion Control and Quality of Service. 23.1 Data Traffic. Traffic Descriptor. Traffic Profiles. Figure 23.1 Traffic descriptors. Figure 23.2 Constant-bit-rate traffic. Figure 23.3 Variable-bit-rate traffic. Figure 23.4 Bursty traffic. 23.2 Congestion.

dahlia
Download Presentation

Chapter 23

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 23 Congestion ControlandQuality of Service

  2. 23.1 Data Traffic Traffic Descriptor Traffic Profiles

  3. Figure 23.1Traffic descriptors

  4. Figure 23.2Constant-bit-rate traffic

  5. Figure 23.3Variable-bit-rate traffic

  6. Figure 23.4Bursty traffic

  7. 23.2 Congestion Network Performance

  8. Figure 23.5Incoming packet

  9. Figure 23.6Packet delay and network load

  10. Figure 23.7Throughput versus network load

  11. 23.3 Congestion Control Open Loop Open Loop Closed Loop

  12. 23.4 Two Examples Congestion Control in TCP Congestion Control in Frame Relay

  13. Note: TCP assumes that the cause of a lost segment is due to congestion in the network.

  14. Note: If the cause of the lost segment is congestion, retransmission of the segment does not remove the cause—it aggravates it.

  15. Figure 23.8Multiplicative decrease

  16. Figure 23.9BECN

  17. Figure 23.10FECN

  18. Figure 23.11Four cases of congestion

  19. 23.5 Quality of Service Flow Characteristics Flow Classes

  20. 23.6 Techniques to Improve QoS Scheduling Traffic Shaping Resource Reservation Admission Control

  21. Figure 23.12Flow characteristics

  22. Figure 23.13FIFO queue

  23. Figure 23.14Priority queuing

  24. Figure 23.15Weighted fair queuing

  25. Figure 23.16Leaky bucket

  26. Figure 23.17Leaky bucket implementation

  27. Note: 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.

  28. Flowchart for Leaky Bucket Algorithm

  29. Example of Leaky Bucket Algorithm

  30. Figure 23.18Token bucket

  31. Note: The token bucket allows bursty traffic at a regulated maximum rate.

  32. 23.7 Integrated Services Signaling Flow Specification Admission Service Classes RSVP

  33. Note: Integrated Services is a flow-based QoS model designed for IP.

  34. Figure 23.19Path messages

  35. Figure 23.20Resv messages

  36. Figure 23.21Reservation merging

  37. Figure 23.22Reservation styles

  38. 23.8 Differentiated Services An Alternative to Integrated Services

  39. Note: Differentiated Services is a class-based QoS model designed for IP.

  40. Figure 23.23DS field

  41. Figure 23.24Traffic conditioner

  42. 23.9 QoS in Switched Networks QoS in Frame Relay QoS in ATM

  43. Figure 23.25Relationship between traffic control attributes

  44. Figure 23.26User rate in relation to Bc and Bc + Be

  45. Figure 23.27Service classes

  46. Figure 23.28Relationship of service classes to the total capacity

More Related