ZyXEL P-202H User Guide - Page 191

PPP Multilink, Bandwidth on Demand

Page 191 highlights

P-202H Plus v2 User's Guide 20.4 PPP Multilink The ZyXEL Device uses the PPP Multilink Protocol (PPP/MP) to bundle multiple links in a single connection to boost the effective throughput between two nodes. Due to the fragmentation/reconstruction overhead associated with MP, you may not get a linear increase in throughput when a link is added. The number of links in an MP bundle can be statically configured, or dynamically determined at runtime, as explained in the following section. 20.5 Bandwidth on Demand The Bandwidth on Demand (BOD) feature adds or subtracts links dynamically according to traffic demand. After the initial call, the ZyXEL Device uses BAP (Bandwidth Allocation Protocol) to ask the peer for additional telephone number if BACP (Bandwidth Allocation Control Protocol) is negotiated. Otherwise, the ZyXEL Device uses the statically configured (primary and secondary) telephone numbers of the remote node. The configuration of bandwidth on demand focuses on the Base Transmission Rate (BTR) and the Maximum Transmission Rate (MTR). The relationship between BTR and MTR are shown in the following table: Table 65 BTR vs MTR for BOD BTR AND MTR SETTING NO. OF CHANNEL(S) USED MAX NO. OF CHANNEL(S) USED BTR = 64, MTR = 64 1 1 BTR = 64, MTR = 128 1 2 BTR = 128, MTR = 128 2 2 BANDWIDTH ON DEMAND Off On Off When bandwidth on demand is enabled, a second channel will be brought up if traffic on the initial channel is higher than the high Target Utility number for longer than the specified Add Persist value. Similarly, the second channel will be dropped if the traffic level falls below the low Target Utility number for longer than the Subtract Persist value. The Target Utility specifies the line utilization range at which you want the ZyXEL Device to add or subtract bandwidth. The range is 30 to 64 Kbps (kilobits per second). The parameters are separated by a '-'. For example, '30-60' means the add threshold is 30 Kbps and subtract threshold is 60 Kbps. The ZyXEL Device performs bandwidth on demand only if it initiates the call. Addition and subtraction are based on the value set in the BOD Calculation field. If this field is set to Transmit or Receive, then traffic in either direction will be included to determine if a link should be added or dropped. Transmit will only use outgoing traffic to make this determination and Receive will only use incoming traffic to make this determination. Chapter 20 Remote Node Configuration 190

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375

P-202H Plus v2 User’s Guide
Chapter 20 Remote Node Configuration
190
20.4
PPP Multilink
The ZyXEL Device uses the PPP Multilink Protocol (PPP/MP) to bundle multiple links in a
single connection to boost the effective throughput between two nodes.
Due to the fragmentation/reconstruction overhead associated with MP, you may not get a
linear increase in throughput when a link is added.
The number of links in an MP bundle can be statically configured, or dynamically determined
at runtime, as explained in the following section.
20.5
Bandwidth on Demand
The Bandwidth on Demand (BOD) feature adds or subtracts links dynamically according to
traffic demand. After the initial call, the ZyXEL Device uses BAP (Bandwidth Allocation
Protocol) to ask the peer for additional telephone number if BACP (Bandwidth Allocation
Control Protocol) is negotiated. Otherwise, the ZyXEL Device uses the statically configured
(primary and secondary) telephone numbers of the remote node.
The configuration of bandwidth on demand focuses on the Base Transmission Rate (BTR) and
the Maximum Transmission Rate (MTR). The relationship between BTR and MTR are shown
in the following table:
When bandwidth on demand is enabled, a second channel will be brought up if traffic on the
initial channel is higher than the high
Target Utility
number for longer than the specified
Add
Persist
value. Similarly, the second channel will be dropped if the traffic level falls below the
low
Target Utility
number for longer than the
Subtract Persist
value.
The
Target Utility
specifies the line utilization range at which you want the ZyXEL Device to
add or subtract bandwidth. The range is 30 to 64 Kbps (kilobits per second). The parameters
are separated by a '-'. For example, '30-60' means the add threshold is 30 Kbps and subtract
threshold is 60 Kbps. The ZyXEL Device performs bandwidth on demand only if it initiates
the call. Addition and subtraction are based on the value set in the
BOD Calculation
field. If
this field is set to
Transmit or Receive
, then traffic in either direction will be included to
determine if a link should be added or dropped.
Transmit
will only use outgoing traffic to
make this determination and
Receive
will only use incoming traffic to make this
determination.
Table 65
BTR vs MTR for BOD
BTR AND MTR SETTING
NO. OF CHANNEL(S)
USED
MAX NO. OF
CHANNEL(S) USED
BANDWIDTH ON
DEMAND
BTR = 64, MTR = 64
1
1
Off
BTR = 64, MTR = 128
1
2
On
BTR = 128, MTR = 128
2
2
Off