Traffic Management for the Available Bit Rate (ABR) Service in ...
Traffic Management for the Available Bit Rate (ABR) Service in ... Traffic Management for the Available Bit Rate (ABR) Service in ...
4.11.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 4.12 HKUST Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 4.12.1 Key Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 86 4.12.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 4.13 SP-EPRCA scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 4.13.1 Key Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 88 4.13.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 4.14 Summary of Switch Congestion Control Schemes . . . . . . . . . . 91 4.14.1 Common Drawbacks . . . . . . . . . . . . . . . . . . . . . . 92 5. The Ohio State University (OSU) Scheme . . . . . . . . . . . . . . . . . 95 5.1 The Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 5.1.1 Control-Cell Format . . . . . . . . . . . . . . . . . . . . . . 96 5.1.2 The Source Algorithm . . . . . . . . . . . . . . . . . . . . . 98 5.1.3 The Switch Algorithm . . . . . . . . . . . . . . . . . . . . . 100 5.1.4 The Destination Algorithm . . . . . . . . . . . . . . . . . . 104 5.1.5 Initialization Issues . . . . . . . . . . . . . . . . . . . . . . . 104 5.2 Key Features and Contributions of the OSU scheme . . . . . . . . . 105 5.2.1 Congestion Avoidance . . . . . . . . . . . . . . . . . . . . . 105 5.2.2 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 5.2.3 Use Measured Rather Than Declared Loads . . . . . . . . . 108 5.2.4 Congestion Detection: Input Rate vs Queue Length . . . . . 108 5.2.5 Bipolar Feedback . . . . . . . . . . . . . . . . . . . . . . . . 111 5.2.6 Count the Number of Active Sources . . . . . . . . . . . . . 112 5.2.7 Order 1 Operation . . . . . . . . . . . . . . . . . . . . . . . 113 5.2.8 Backward Congestion Noti cations Cannot Be Used to Increase113 5.3 Extensions of The OSU Scheme . . . . . . . . . . . . . . . . . . . . 114 5.3.1 Aggressive Fairness Option . . . . . . . . . . . . . . . . . . 114 5.3.2 Precise Fair Share Computation Option . . . . . . . . . . . 117 5.3.3 BECN Option . . . . . . . . . . . . . . . . . . . . . . . . . 119 5.4 Other Simple Variants of the OSU Scheme . . . . . . . . . . . . . . 121 5.5 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 5.5.1 Default Parameter Values . . . . . . . . . . . . . . . . . . . 123 5.5.2 Single Source . . . . . . . . . . . . . . . . . . . . . . . . . . 123 5.5.3 Two Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5.5.4 Three Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5.5.5 Transient Sources . . . . . . . . . . . . . . . . . . . . . . . . 125 5.5.6 Parking Lot . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 5.5.7 Upstream Bottleneck . . . . . . . . . . . . . . . . . . . . . . 127 5.6 Results for WAN Con guration . . . . . . . . . . . . . . . . . . . . 130 5.7 Results with Packet Train Workload . . . . . . . . . . . . . . . . . 132 ix
5.8 Proof: Fairness Algorithm Improves Fairness . . . . . . . . . . . . . 138 5.8.1 Proof of Claim C1 . . . . . . . . . . . . . . . . . . . . . . . 139 5.8.2 Proof of Claim C2 . . . . . . . . . . . . . . . . . . . . . . . 141 5.8.3 Proof for Asynchronous Feedback Conditions . . . . . . . . 145 5.9 Current Tra c Management Speci cations vs OSU Scheme . . . . 147 5.10 Limitations and Summary of the OSU Scheme . . . . . . . . . . . . 148 6. The ERICA and ERICA+ Schemes . . . . . . . . . . . . . . . . . . . . . 153 6.1 The Basic ERICA Algorithm . . . . . . . . . . . . . . . . . . . . . 154 6.2 Achieving Max-Min Fairness . . . . . . . . . . . . . . . . . . . . . . 156 6.3 Fairshare First to Avoid Transient Overloads . . . . . . . . . . . . 157 6.4 Forward CCR Used for Reverse Direction Feedback . . . . . . . . . 159 6.5 Single Feedback in a Switch Interval . . . . . . . . . . . . . . . . . 160 6.6 Per-VC CCR Measurement Option . . . . . . . . . . . . . . . . . . 161 6.7 ABR Operation with VBR and CBR in the Background . . . . . . 163 6.8 Bi-directional Counting of Bursty Sources . . . . . . . . . . . . . . 164 6.9 Averaging of the Number of Sources . . . . . . . . . . . . . . . . . 165 6.10 Boundary Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 6.11 Averaging of the Load Factor . . . . . . . . . . . . . . . . . . . . . 166 6.12 Time and Count Based Averaging . . . . . . . . . . . . . . . . . . 168 6.13 Selection of ERICA Parameters . . . . . . . . . . . . . . . . . . . . 169 6.13.1 Target Utilization U . . . . . . . . . . . . . . . . . . . . . . 170 6.13.2 Switch Averaging Interval AI . . . . . . . . . . . . . . . . . 171 6.14 ERICA+: Queue Length as a Secondary Metric . . . . . . . . . . . 172 6.15 ERICA+: 100% Utilization and Quick Drain of Queues . . . . . . . 173 6.16 ERICA+: Maintain a \Pocket" of Queues . . . . . . . . . . . . . . 174 6.17 ERICA+: Scalability toVarious Link Speeds . . . . . . . . . . . . 174 6.18 ERICA+: Target Operating Point . . . . . . . . . . . . . . . . . . 175 6.19 The ERICA+ Scheme . . . . . . . . . . . . . . . . . . . . . . . . . 176 6.20 E ect of Variation on ERICA+ . . . . . . . . . . . . . . . . . . . . 180 6.21 Selection of ERICA+ Parameters . . . . . . . . . . . . . . . . . . . 182 6.21.1 Parameters a and b . . . . . . . . . . . . . . . . . . . . . . . 182 6.21.2 Target Queueing Delay T 0. . . . . . . . . . . . . . . . . . . 183 6.21.3 Queue Drain Limit Factor QDLF . . . . . . . . . . . . . . 185 6.22 Performance Evaluation of the ERICA and ERICA+ Schemes . . . 186 6.22.1 Parameter Settings . . . . . . . . . . . . . . . . . . . . . . . 187 6.22.2 E ciency . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 6.22.3 Minimal Delay andQueue Lengths . . . . . . . . . . . . . . 189 6.22.4 Fairness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.22.5 Transient and Steady State Performance . . . . . . . . . . . 192 6.22.6 Adaptation to Variable ABR Capacity . . . . . . . . . . . . 193 x
- Page 1 and 2: Tra c Management for the Available
- Page 3 and 4: ABSTRACT With the merger of telecom
- Page 5 and 6: Tra c Management for the Available
- Page 7 and 8: To my family iv
- Page 9 and 10: VITA April 30, 1971 :::::::::::::::
- Page 11: 2.7 Switch Behavior . . . . . . . .
- Page 15 and 16: 8.15 Factors A ecting Bu ering Requ
- Page 17 and 18: Bibliography . . . . . . . . . . .
- Page 19 and 20: 8.12 Maximum Queues for Satellite N
- Page 21 and 22: 5.1 Transmitted cell rate (instanta
- Page 23 and 24: 6.13 Results foratwo sources con gu
- Page 25 and 26: 7.11 E ect of UILI on Medium Bursts
- Page 27 and 28: C.3 Flow Chart of Bi-Directional Co
- Page 29 and 30: header information which limits the
- Page 31 and 32: switches since a standard does not
- Page 33 and 34: congestion control deals with the c
- Page 35 and 36: hand side of the equation is the su
- Page 37 and 38: analyses which are used to validate
- Page 39 and 40: CHAPTER 2 THE ABR TRAFFIC MANAGEMEN
- Page 41 and 42: time (RTT). As we explain later, AB
- Page 43 and 44: feedback from nearby switches to re
- Page 45 and 46: Note that in-rate and out-of-rate d
- Page 47 and 48: Data cells also have an Explicit Fo
- Page 49 and 50: opportunity the source may nd that
- Page 51 and 52: Figure 2.7: Scheduling of forward R
- Page 53 and 54: as the timeout value) which reduces
- Page 55 and 56: It has been incorrectly believed th
- Page 57 and 58: NI CI Action 0 0 ACR Min(ER, ACR +
- Page 59 and 60: Source Rule 13: Sources can optiona
- Page 61 and 62: Switch Rule 1: This rule speci es t
5.8 Proof: Fairness Algorithm Improves Fairness . . . . . . . . . . . . . 138<br />
5.8.1 Proof of Claim C1 . . . . . . . . . . . . . . . . . . . . . . . 139<br />
5.8.2 Proof of Claim C2 . . . . . . . . . . . . . . . . . . . . . . . 141<br />
5.8.3 Proof <strong>for</strong> Asynchronous Feedback Conditions . . . . . . . . 145<br />
5.9 Current Tra c <strong>Management</strong> Speci cations vs OSU Scheme . . . . 147<br />
5.10 Limitations and Summary of <strong>the</strong> OSU Scheme . . . . . . . . . . . . 148<br />
6. The ERICA and ERICA+ Schemes . . . . . . . . . . . . . . . . . . . . . 153<br />
6.1 The Basic ERICA Algorithm . . . . . . . . . . . . . . . . . . . . . 154<br />
6.2 Achiev<strong>in</strong>g Max-M<strong>in</strong> Fairness . . . . . . . . . . . . . . . . . . . . . . 156<br />
6.3 Fairshare First to Avoid Transient Overloads . . . . . . . . . . . . 157<br />
6.4 Forward CCR Used <strong>for</strong> Reverse Direction Feedback . . . . . . . . . 159<br />
6.5 S<strong>in</strong>gle Feedback <strong>in</strong> a Switch Interval . . . . . . . . . . . . . . . . . 160<br />
6.6 Per-VC CCR Measurement Option . . . . . . . . . . . . . . . . . . 161<br />
6.7 <strong>ABR</strong> Operation with VBR and CBR <strong>in</strong> <strong>the</strong> Background . . . . . . 163<br />
6.8 Bi-directional Count<strong>in</strong>g of Bursty Sources . . . . . . . . . . . . . . 164<br />
6.9 Averag<strong>in</strong>g of <strong>the</strong> Number of Sources . . . . . . . . . . . . . . . . . 165<br />
6.10 Boundary Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165<br />
6.11 Averag<strong>in</strong>g of <strong>the</strong> Load Factor . . . . . . . . . . . . . . . . . . . . . 166<br />
6.12 Time and Count Based Averag<strong>in</strong>g . . . . . . . . . . . . . . . . . . 168<br />
6.13 Selection of ERICA Parameters . . . . . . . . . . . . . . . . . . . . 169<br />
6.13.1 Target Utilization U . . . . . . . . . . . . . . . . . . . . . . 170<br />
6.13.2 Switch Averag<strong>in</strong>g Interval AI . . . . . . . . . . . . . . . . . 171<br />
6.14 ERICA+: Queue Length as a Secondary Metric . . . . . . . . . . . 172<br />
6.15 ERICA+: 100% Utilization and Quick Dra<strong>in</strong> of Queues . . . . . . . 173<br />
6.16 ERICA+: Ma<strong>in</strong>ta<strong>in</strong> a \Pocket" of Queues . . . . . . . . . . . . . . 174<br />
6.17 ERICA+: Scalability toVarious L<strong>in</strong>k Speeds . . . . . . . . . . . . 174<br />
6.18 ERICA+: Target Operat<strong>in</strong>g Po<strong>in</strong>t . . . . . . . . . . . . . . . . . . 175<br />
6.19 The ERICA+ Scheme . . . . . . . . . . . . . . . . . . . . . . . . . 176<br />
6.20 E ect of Variation on ERICA+ . . . . . . . . . . . . . . . . . . . . 180<br />
6.21 Selection of ERICA+ Parameters . . . . . . . . . . . . . . . . . . . 182<br />
6.21.1 Parameters a and b . . . . . . . . . . . . . . . . . . . . . . . 182<br />
6.21.2 Target Queue<strong>in</strong>g Delay T 0. . . . . . . . . . . . . . . . . . . 183<br />
6.21.3 Queue Dra<strong>in</strong> Limit Factor QDLF . . . . . . . . . . . . . . 185<br />
6.22 Per<strong>for</strong>mance Evaluation of <strong>the</strong> ERICA and ERICA+ Schemes . . . 186<br />
6.22.1 Parameter Sett<strong>in</strong>gs . . . . . . . . . . . . . . . . . . . . . . . 187<br />
6.22.2 E ciency . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188<br />
6.22.3 M<strong>in</strong>imal Delay andQueue Lengths . . . . . . . . . . . . . . 189<br />
6.22.4 Fairness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190<br />
6.22.5 Transient and Steady State Per<strong>for</strong>mance . . . . . . . . . . . 192<br />
6.22.6 Adaptation to Variable <strong>ABR</strong> Capacity . . . . . . . . . . . . 193<br />
x
Change language