Traffic Management for the Available Bit Rate (ABR) Service in ...

More documents

Recommendations

Info

Seen VC In This Interval[VC] 0 Seen BRM Cell In This Interval[VC] 0 END (* FOR *) ABR Cell Count 0 IF (Per VC CCR Option) THEN FOR ALL VCs DO CCR[VC] Number Of Cells[VC]=Averaging Interval Number Of Cells[VC] 0 END (* FOR *) END (* IF *) VBR and CBR Cell Count 0 Restart Averaging Interval Timer A Forward RM (FRM) cell of \VC" is received: IF (NOT(Per VC CCR Option)) THEN CCR[VC] CCR In FRM Cell END (* IF *) A Backward RM (BRM) cell of \VC" is received: IF (Averaging VCs Option) THEN IF (Contribution[VC] < 1) THEN (* VC inactive in current interval *) Number Active VCs In This Interval Number Active VCs In This Interval ; Contribution[VC] + 1 IF ((Immediate Fairshare Update Option) AND (Contribution[VC] < Decay Factor)) THEN Number Active VCs In Last Interval Number Active VCs In Last Interval 403
; (Contribution[VC] = Decay Factor) + 1 Fair Share ABR Capacity In cps = Number Active VCs In Last Interval END (* IF (Immediate ...) *) Contribution[VC] 1 END (* IF (Contribution ... ) *) ELSE (* NOT (Averaging VCs Option) *) IF (NOT(Seen VC In This Interval[VC])) THEN Seen VC In This Interval[VC] 1 END (* IF *) IF ((Immediate Fair Share Option) AND (NOT(Seen VC In Last Interval[VC]))) THEN 1 Number Active VCs In Last Interval Number Active VCs In Last Interval + Fair Share ABR Capacity In cps = Number Active VCs In Last Interval Seen VC In Last Interval[VC] 1 END (* IF ((Immediate ..)) *) END (* IF-THEN-ELSE (Averaging VCs Option) *) IF (Seen BRM Cell In This Interval[VC]) THEN ELSE ER Calculated Last Allocated ER[VC] VC Share[VC] CCR[VC] = Load Factor (* Max-Min Fairness Algorithm *) IF (Load Factor > 1+ ) THEN 404
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 and 12:
2.7 Switch Behavior . . . . . . . .
Page 13 and 14:
5.8 Proof: Fairness Algorithm Impro
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
Page 63 and 64:
Observe that the ABR tra c manageme
Page 65 and 66:
complex method like per-VC queuing
Page 67 and 68:
graphs have a steady state with con
Page 69 and 70:
Figure 3.2: Operating point between
Page 71 and 72:
The following example illustrates t
Page 73 and 74:
mention this concept of fairness fo
Page 75 and 76:
control problem was also simpler. S
Page 77 and 78:
of such an occurrence is expected t
Page 79 and 80:
y giving only one feedback per meas
Page 81 and 82:
CHAPTER 4 SURVEY OF ATM SWITCH CONG
Page 83 and 84:
The adaptive FCVC algorithm [63] co
Page 85 and 86:
np. Thus, long path VCs have fewer
Page 87 and 88:
networks like ATM can have complete
Page 89 and 90:
scheme followed by a discussion of
Page 91 and 92:
exibility of decoupling the enforce
Page 93 and 94:
4.6.1 Key Techniques In EPRCA, the
Page 95 and 96:
If the mean ACR is not a good estim
Page 97 and 98:
is the ratio of the input rate to t
Page 99 and 100:
which shares the link equally as al
Page 101 and 102:
proportional to the the unused ABR
Page 103 and 104:
The key technique in the scheme is
Page 105 and 106:
the bandwidth allocations to satis
Page 107 and 108:
4.10 DMRCA scheme The Dynamic Max R
Page 109 and 110:
on its CCR. Further MAX times out i
Page 111 and 112:
other words, a di erent set of para
Page 113 and 114:
A combination of several ideas in a
Page 115 and 116:
4.13 SP-EPRCA scheme The SP-EPRCA s
Page 117 and 118:
RTD and shuts o the source (for sta
Page 119 and 120:
4.14.1 Common Drawbacks Though the
Page 121 and 122:
The ATM Tra c Management standard a
Page 123 and 124:
5.1.1 Control-Cell Format The contr
Page 125 and 126:
The last two elds are used in the b
Page 127 and 128:
Figure 5.3: Flow chart for updating
Page 129 and 130:
LAF in cell Max(LAF in cell, z) The
Page 131 and 132:
the time of departure (instant mark
Page 133 and 134:
the steady state. The system operat
Page 135 and 136:
5.2.3 Use Measured Rather Than Decl
Page 137 and 138:
said about the maximum queue length
Page 139 and 140:
The key problem with some unipolar
Page 141 and 142:
Figure 5.6: Space time diagram show
Page 143 and 144:
As noted, these heuristics do not g
Page 145 and 146:
Transmitted Cell Rate ABR Queue Len
Page 147 and 148:
4. The RM cell contains a timestamp
Page 149 and 150:
1. The source o ered average cell r
Page 151 and 152:
Transmitted Cell Rate Link Utilizat
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Figure 5.17: The parking lot fairne
Page 159 and 160:
Figure 5.19: Network con guration w
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
5.8 Proof: Fairness Algorithm Impro
Page 167 and 168:
Region 2: y s and x s and U(1 + ) x
Page 169 and 170:
eing divided into eight non-overlap
Page 171 and 172:
Proof for Region 2 Triangular regio
Page 173 and 174:
have: and y 0 = y(1 ; ) z x + y 0 =
Page 175 and 176:
The OSU scheme is, therefore, incom
Page 177 and 178:
workloads, where input load and cap
Page 179 and 180:
(a) Regions used to prove Claim C1
Page 181 and 182:
6.1 The Basic ERICA Algorithm The s
Page 183 and 184:
A ow chart of the basic algorithm i
Page 185 and 186:
efore competing sources can receive
Page 187 and 188:
that the latest CCR information is
Page 189 and 190:
the CCR value may not be an accurat
Page 191 and 192:
(Target Utilization) (Link Bandwidt
Page 193 and 194:
ABR Capacity Input Rate Overload Fa
Page 195 and 196:
of arithmetic averaging used above.
Page 197 and 198:
level of control. These parameters
Page 199 and 200:
6.14 ERICA+: Queue Length as a Seco
Page 201 and 202:
6.16 ERICA+: Maintain a \Pocket" of
Page 203 and 204:
hence, introduces a new parameter,
Page 205 and 206:
Figure 6.4: Linear functions for ER
Page 207 and 208:
and Figure 6.6: The queue control f
Page 209 and 210:
small averaging intervals. If the a
Page 211 and 212:
The maximum value of T 0 also depen
Page 213 and 214:
6.22 Performance Evaluation of the
Page 215 and 216:
espectively. The target delay T 0 i
Page 217 and 218:
6.22.4 Fairness Figure 6.9: Parking
Page 219 and 220:
st link, VC 15 is limited to a thro
Page 221 and 222:
From the gures, it is clear that ER
Page 223 and 224:
counts the bursty source as active
Page 225 and 226:
6.23 Summary of the ERICA and ERICA
Page 227 and 228:
(a) Transmitted Cell Rate (c) Link
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
(a) Transmitted Cell Rate (basic ER
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
RM cells. In this chapter, we devot
Page 253 and 254:
low. This tradeo was discovered and
Page 255 and 256:
in the speci cation. b) ACR shall n
Page 257 and 258:
7.1.6 December 1995 Proposals There
Page 259 and 260:
Figure 7.2: Multiplicative vsAdditi
Page 261 and 262:
is never triggered. However, the PR
Page 263 and 264:
simulation results of bursty source
Page 265 and 266:
1. The time-based proposal also ind
Page 267 and 268:
The switch maintains a local alloca
Page 269 and 270:
PNI = f0, 1g : f1 ) No rule 5b, 0 )
Page 271 and 272:
after reaching the goal. The time-b
Page 273 and 274:
Figure 7.8: Closed-Loop Bursty Tra
Page 275 and 276:
The algorithm measures the load and
Page 277 and 278:
Medium Bursts Medium bursts are exp
Page 279 and 280:
count-based technique may be insu c
Page 281 and 282:
Figure 7.13: An event trace illustr
Page 283 and 284:
CHAPTER 8 SUPPORTING INTERNET APPLI
Page 285 and 286:
u ering which does not depend upon
Page 287 and 288:
4 make it to the destination are ar
Page 289 and 290:
Figure 8.3: At the ATM layer, the T
Page 291 and 292:
issues and e ect of bursty applicat
Page 293 and 294:
from the loss and they trigger the
Page 295 and 296:
8.8 Performance Metrics We measure
Page 297 and 298:
the performance is fair. Also, the
Page 299 and 300:
Figure 8.7(b) shows the rates (ACRs
Page 301 and 302:
Window Size in bytes vfive-tcp/opti
Page 303 and 304:
The e ect of large bu ers on CLR is
Page 305 and 306:
8.13 Summary of TCP/IP performance
Page 307 and 308:
Feedback delay: Twice the delay fro
Page 309 and 310:
on a link, two cells are expected a
Page 311 and 312:
state only after the switch algorit
Page 313 and 314:
queue length is less susceptible to
Page 315 and 316:
to equalize rates for fairness, and
Page 317 and 318:
QB = Link bandwidth (RT T ; T ) and
Page 319 and 320:
u ered at the end-system, and not i
Page 321 and 322:
Part b): When ABR load goes away, t
Page 323 and 324:
All our simulations presented use t
Page 325 and 326:
Averaging RTT(ms) Feedback Max Q Th
Page 327 and 328:
a modi ed version of the ERICA algo
Page 329 and 330:
ABR is better than UBR in these (en
Page 331 and 332:
problems. During the ON time, the V
Page 333 and 334:
hand, the frequency of the VBR is h
Page 335 and 336:
like ERICA+ which uses the queueing
Page 337 and 338:
minimum fairshare is low. This may
Page 339 and 340:
8.17 E ect of Long-Range Dependent
Page 341 and 342:
terminology) are called \Presentati
Page 343 and 344:
The key point is that the MPEG-2 ra
Page 345 and 346:
the MPEG-2 Transport Stream, and st
Page 347 and 348:
8.17.4 Observations on the Long-Ran
Page 349 and 350:
For the video sources, we choose me
Page 351 and 352:
Video Sources ABR Metrics # Mean St
Page 353 and 354:
However, with modi cations to ERICA
Page 355 and 356:
Video Sources ABR Metrics # Avg Src
Page 357 and 358:
Video Sources ABR Metrics # Avg Src
Page 359 and 360:
On the other hand, if the applicati
Page 361 and 362:
of managing bu ers, queueing, sched
Page 363 and 364:
hence control the total load on the
Page 365 and 366:
call such a switch a \VS/VD switch"
Page 367 and 368:
Figure 9.2: Per-class queues in a n
Page 369 and 370:
which arises is where the rate calc
Page 371 and 372:
9.2 The ERICA Switch Scheme: Renota
Page 373 and 374:
The unknowns in the above equations
Page 375 and 376:
Figure 9.9: Two methods to measure
Page 377 and 378:
9.4 VS/VD Switch Design Options 9.4
Page 379 and 380: # VC Rate VC Input Rate Input Rate
Page 381 and 382: 8 uses source rate measurement, we
Page 383 and 384: The allocated rate update and the e
Page 385 and 386: sources in chapter 6. We expect the
Page 387 and 388: con guration mentioned in the table
Page 389 and 390: can be very di erent for di erent V
Page 391 and 392: CHAPTER 10 IMPLEMENTATION ISSUES At
Page 393 and 394: With an enhanced UBR service, appli
Page 395 and 396: 2. Some switch schemes have a proce
Page 397 and 398: 4. Large legacy switches have a pro
Page 399 and 400: section 9. Further, WAN switches wo
Page 401 and 402: CHAPTER 11 SUMMARY AND FUTURE WORK
Page 403 and 404: good transient performance. Since r
Page 405 and 406: variant background tra c conditions
Page 407 and 408: APPENDIX A SOURCE, DESTINATION AND
Page 409 and 410: 7. After following behaviors #5 and
Page 411 and 412: set the QL and SN elds to zero, pre
Page 413 and 414: d) VS/VD Control: The switch may se
Page 415 and 416: 5. Setting of other parameters at V
Page 417 and 418: 4. The averaging interval timer exp
Page 419 and 420: 1. Initialization: Target Cell Rate
Page 421 and 422: THEN IF (OCR In Cell Fair Share Rat
Page 423 and 424: APPENDIX C ERICA SWITCH ALGORITHM:
Page 425 and 426: Number Active VCs In Last Interval
Page 427 and 428: IF (NOT(Averaging VCs Option)) THEN
Page 429: IF (Load Factor = In nity) THEN Loa
Page 433 and 434: Name Explanation Flow Chart (FC) or
Page 435 and 436: Figure C.2: Flow Chart for Achievin
Page 437 and 438: Figure C.4: Flow Chart of averaging
Page 439 and 440: Figure C.6: Flow chart of averaging
Page 441 and 442: C.3 Pseudocode for VS/VD Design Opt
Page 443 and 444: (* | Bottleneck rate of next loop |
Page 445 and 446: Follow SESRules 1-4 (see appendix A
Page 447 and 448: CRM - Missing RM-cell Count DIR bit
Page 449 and 450: TUB -Target Utilization Band Trm -
Page 451 and 452: [12] J. Bennett and G. Tom Des Jard
Page 453 and 454: [38] M. Grossglauser, S.Keshav, and
Page 455 and 456: [64] H. T. Kung. Flow Controlled Vi
show all

Traffic Management for the Available Bit Rate (ABR) Service in ...

Create successful ePaper yourself

Delete template?

Save as template?