1. Computer Networks: Performance and Quality of Service Ivan Marsic Rutgers University Slides, Part 2

2. Switching and Queuing Delay Models Chapter 4

3. Topic: Packet Switching in Routers  Router Architecture  Forwarding Table Lookup  Switching Fabric Design  How Queuing Happens

4. Routing Delays

5. How Router Forwards Packets

6. Services to Incoming Packets

7. Distribution of Protocol Layers

8. Router Architectures

9. Switching via Memory / via Bus

10. Banyan Switch Fabric

11. Batcher Network

12. Batcher-Banyan Network

13. This figure is meant to illustrate why a concentrator is needed, because otherwise the gap in the input sequence will cause collision in the Banyan, but the example does not work for a 4x4 network -- need an 8x8 network example!!!!

14. Delay Components in Forwarding

15. Road Intersection Analogy

16. An Input-queued Switch

17. Topic: Queuing Models  M / M / 1  M / M / 1/ m  M / G / 1  Networks of Queues

18. General Service Model

19. Simple Queuing Model

20. Delay Time

21. Why Queuing Happens?

22. Arrival Sequences

23. Intuition for the Balance Principle See: Global Balance Equations

24. Transition Probability Diagram

25. M/G/1 Example

26. Expected Residual Time

27. Mechanisms for Quality-of-Service Chapter 5

28. Topic: Scheduling  Max-Min Fair Share  Fair Queuing (FQ)  Weighted Fair Queuing (WFQ)

29. Scheduler

30. Resource Fair Share

31. Max-Min Fair Share (1)

32. Max-Min Fair Share (2)

33. Max-Min Fair Share (3)

34. Example 5.1: Max-Min Fair Share

35. Example: Airport Check-in

36. Bit-by-bit GPS

37. Bit-by-bit GPS -- Example

38. GPS Round Number vs. Time

39. Example 5.3: GPS Round Numbers

40. 016,384@1 04,096@3 316,384@2 38,192@4 64,096@3 124,096@3 Example 5.3: GPS Round Numbers (Cont’d)

41. Example 5.3: Fair Queuing

42. Example 4.4: Fair Queuing (1)

43. Example 4.4: Fair Queuing (2b)

44. Topic: Policing  Leaky Bucket Algorithm

45. Delay Magnitude & Variability

46. Leaky Bucket

47. Wireless Networks Chapter 6

48. Topic: Routing in Wireless Networks  Dynamic Source Routing (DSR) Protocol  Ad Hoc On-Demand Distance-Vector  (AODV) Protocol

49. Route Discovery in DSR (1)

50. Route Discovery in DSR (2) Broadcast Tx Represents a node that has received RREQ for H from C

51. Route Discovery in DSR (3)

52. Route Discovery in DSR (4)

53. Route Discovery in DSR (5)

54. Route Discovery in AODV (1)

55. Multihop Throughput Challenge: more hops, less throughput Links in route share radio spectrum Extra hops reduce throughput Throughput = 1 Throughput = 1/2 Throughput = 1/3

56. Topic: IEEE 802.11n  Multiple Input Multiple Output (MIMO)  Physical Layer Enhancements  MAC Layer Enhancements: Frame Aggregation, Block Acknowledgement, Reverse Direction Protocol  Backward Compatibility

57. IEEE 802.11n - MIMO

58. 802.11n Channel Bonding and 20/40 MHz Operation

59. 802.11n PHY-layer Frame Format

60. IEEE 802.11 Terminology

61. 802.11n MAC-layer Frame Format

62. Packet Aggregation

63. 802.11n Frame Aggregation

64. Frame Aggregation: A-MSDU and A-MPDU

65. Block Acknowledgement Session

66. Block Acknowledgement Frame

67. Block ACK Frame Subfields

68. Block ACK Example

69. Reverse Direction (RD) Protocol Unidirectional vs. Bidirectional RTS/CTS Access Scheme

70. 802.11n Backwards Compatibility Modes: CTS-to-Self

71. Dual-CTS protection (CTS-to-self)

72. Example of L-SIG Duration Setting

73. 802.11n Phased Coexistence Operation (PCO)

74. Topic: QoS in Wireless Networks  IEEE 802.11e

75. Classification of QoS Techniques in 802.11

76. Network Monitoring Chapter 7

77. Packet-pair Dispersion

78. Internet Protocols Chapter 8

79. Topic: IPv6  IPv6 Addresses  IPv6 Extension Headers  Transitioning from IPv4 to IPv6

80. IPv6 Header

81. IPv6 Address Prefix Assignments

82. IPv6 Global Unicast Address

83. Example IPv6 Extension Headers

84. Format of IPv6 Extension Headers

85. Topic: Internet Routing Protocols  Routing Information Protocol (RIP)  Open Shortest Path First (OSPF)  Border Gateway Protocol (BGP): Routing Between and Within ASs, BGP Messages & Path Attributes  Multicast Routing Protocols

86. RIP Header (for IPv4)

87. eBGP and iBGP Sessions

88. BGP Finite State Machine

90. BGP Header & Message Formats

91. BGP UPDATE Message

92. Example BGP UPDATE Message

93. BGP MULTI_EXIT_DISC ( MED ) Attribute

94. Topic: Address Translation Protocols  Address Resolution Protocol (ARP)

95. Address Resolution Protocol (ARP) Need for multiple addresses, hierarchical vs. non-hierarchical

96. Address Resolution Protocol (ARP)

97. ARP Packet Format (for IPv4)

98. Future Trends Chapter 9

99. Wireless Applications Fixed radio cheaper for startup and difficult terrain Wire technologies usually win for large bandwidth non-mobile continuing needs Mobile voice is a “killer app” for wireless Mobile messaging – growth Mobile data has limited usefulness

100. Home Area Networks (HANs)

101. Wired long-distance infrastructure Future Consumer Networks Small islands of wireless on the periphery Bottlenecks are close to the edges

102. Spectrum of Wireless Bandwidth  WANs (cellular, satellite)  LANs (IEEE 802.11/WiFi, HiperLAN)  PANs (Bluetooth) How to achieve seamless mobility between these?

103. Cloud Computing

104. Internet Future Computing Trends Compute-intensive applications run in the Internet core ( e.g., the Computing Grid ) At the Internet periphery: mostly editing, visualization, browsing, querying,… Data sharing and collaboration are key applications Computing Cloud Client p2pc/s Mostly Wireless, Mobile Mostly Fixed

105. Probability Refresher Appendix

106. Jar with Black & White Balls

107. Random Events Possible outcomes of two coin tosses: “Tree diagram” of possible outcomes of two coin tosses:

108. Drawing from Jar/Urn Decided by Rolling a Die

109. Probability Matrix for Ball Drawing

110. Illustration for Bayes Theorem

111. Poisson Process average arrival rate = 5

112. Partitioning of Areas Under Normal Curve

113. How to Read Table A-1