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Algumas informações básicas acerca do CMTS.
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Cisco CMTS Router Downstream and Upstream Features ConfigurationGuideFirst Published: February 14, 2008
Last Modified: June 16, 2014
Americas HeadquartersCisco Systems, Inc.170 West Tasman DriveSan Jose, CA 95134-1706USAhttp://www.cisco.comTel: 408 526-4000 800 553-NETS (6387)Fax: 408 527-0883
Text Part Number: OL-27606-08
2008-2014 Cisco Systems, Inc. All rights reserved.
C O N T E N T S
C H A P T E R 1 Cable Modem Upstream RF Adaptation 1
Prerequisites for Cable Modem Upstream RF Adaptation 2
Restrictions for Cable Modem Upstream RF Adaptation 3
Information About Cable Modem Upstream RF Adaptation 3
Related CMTS Software Features 4
How to Configure Cable Modem Upstream RF Adaptation 5
Troubleshooting Tips 9
Cable Modem Does Not Downgrade to the Secondary Logical Channel 9
Cable Modem Does Not Upgrade to the Primary Logical Channel 9
Verifying Cable Modem Upstream RF Adaptation 10
Configuration Examples for Cable Modem Upstream RF Adaptation 10
Example: Configuring Cable Modem Upstream RF Adaptation on the Cisco uBR10012
Router 10
Example: Configuring Cable Modem Upstream RF Adaptation on the Cisco uBR7200
Router 11
Example: Non-Default Timer Configuration 12
Additional References 13
Feature Information for Cable Modem Upstream RF Adaptation 13
C H A P T E R 2 Configuring Downstream Cable Interface Features on the Cisco CMTS Routers 17
Prerequisites for Configuring Downstream Cable Interfaces on the Cisco CMTS Routers 18
Activating Downstream Cable Address Resolution Protocol Requests 19
Activating Downstream Ports 21
Assigning the Downstream Channel ID 22
Verifying the Downstream Channel ID 22
Traffic Shaping 23
Downstream Traffic Shaping 23
Configuring Downstream Rate Limiting and Traffic Shaping 24
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 iii
Setting the Downstream Helper Address 25
Verifying the Downstream Helper Address 25
Setting the Downstream Interleave Depth 26
Verifying the Downstream Interleave Depth 26
Setting the Downstream Modulation 27
Verifying the Downstream Modulation 27
Setting the Downstream MPEG Framing Format 28
Verifying the Downstream MPEG Framing Format 28
Setting Downstream Traffic Shaping 28
Verifying Downstream Traffic shaping 29
Activating Host-to-Host Communication (Proxy ARP) 30
Activating Cable Proxy ARP Requests 30
Verifying Cable Proxy ARP Requests 30
Activating Packet Intercept Capabilities 31
Configuring Payload Header Suppression and Restoration 31
Setting Optional Broadcast and Cable IP Multicast Echo 32
Setting IP Multicast Echo 32
Verifying IP Multicast Echo 32
Access Lists and the cable ip-multicast echo Command 33
Setting IP Broadcast Echo 33
Verifying IP Broadcast Echo 34
Cable Interface Configuration Examples 34
Example: Subinterface Configuration 34
Example: Cable Interface Bundling 34
Example: Subinterface Definition on Bundle Master 35
Example: Cable Interface Bundle Master Configuration 35
Example: PE Router Configuration 35
Example: Router Configuration 39
Example: Configuring BGP Routing Sessions 40
Example: Configuring PE-to-PE Routing Sessions 40
Example: Configuring BGP PE-to-CE Routing Sessions 41
Example: Configuring RIP PE-to-CE Routing Sessions 41
Example: Configuring Static Route PE-to-CE Routing Sessions 42
C H A P T E R 3 Configuring Upstream Cable Interface Features on the Cisco CMTS Routers 43
Cisco CMTS Router Downstream and Upstream Features Configuration Guideiv OL-27606-08
Contents
Prerequisites for Configuring Upstream Cable Interfaces on the Cisco CMTS Routers 44
Prioritizing Upstream Traffic to Initialize Cable Modems 45
Configuring the Priority of the QoS Profile 46
Activating the Upstream Minimum Reserved Traffic Rate Plus Excess Traffic Rate 47
Activating Upstream Admission Control 48
Verifying Upstream Admission Control 49
Activating Upstream Differential Encoding 49
Verifying Upstream Differential Encoding 49
Activating Upstream Forward Error Correction 50
Verifying Upstream FEC 50
Activating the Upstream Ports 51
Activating Upstream Power Adjustment 52
Activating the Upstream Scrambler 53
Verifying the Upstream Scrambler 53
Activating Upstream Timing Adjustment 54
Verifying Upstream Timing Adjustment 54
Traffic Shaping 55
Upstream Traffic Shaping 55
Upstream Buffer Control for Maximum Queue Depth 56
Configuring Upstream Rate Limiting and Traffic Shaping 57
Setting Upstream Backoff Values 58
Setting the Upstream Channel Width 59
Verifying Upstream Channel Width 60
Copy and Paste Support for TDMA to A-TDMA Upgrade 61
Setting the Upstream Frequency 61
Verifying the Upstream Frequency 63
Setting the Upstream Input Power Level 63
Verifying the Upstream Input Power Level 64
Specifying Upstream Minislot Size 65
Verifying Upstream Minislot Size 65
Setting Upstream Traffic Shaping 66
Verifying Upstream Bandwidth Request Shaping 67
Troubleshooting Tips 68
Configuring Upstream Drop Classifier 68
Setting Upstream Buffer Control Parameters 69
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 v
Contents
Verifying Upstream Buffer Control Parameters 70
Additional References 72
Feature Information for Configuring UpstreamCable Interface Features on the Cisco CMTS
Routers 73
C H A P T E R 4 Cable Modem Steering on the Cisco CMTS Routers 75
Prerequisites for Cable Modem Steering 76
Restrictions for Cable Modem Steering 77
Information About Cable Modem Steering 78
Channel Redirection 79
Channel Restriction 79
Upstream Channel Descriptor TLV for Ranging Hold-off 80
Ranging Class ID 80
Cable Modem Exclusion for DOCSIS Load Balance 80
How to Configure Cable Modem Steering on the CMTS Router 80
Configuring a Channel Redirection 80
Configuring a Channel Restriction 81
Configuring an Upstream Channel Class ID 82
Configuring an Upstream Ranging Hold-off Priority Value 84
Configuration Examples for Cable Modem Steering 85
Example: Configuring a Channel Class ID and Ranging Hold-off Priority Value 85
Example: Clearing a Channel Redirection 85
Verifying and Troubleshooting Cable Modem Steering 86
Verifying a Channel Redirection 86
Verifying a Channel Restriction 87
Verifying an Upstream Ranging Class ID Configuration 88
Clearing Attribute Masks 92
Debugging Channel Redirection 92
Troubleshooting Tips 93
Additional References 93
Feature Information for Cable Modem Steering 95
C H A P T E R 5 DOCSIS 2.0 A-TDMAModulation Profiles for the Cisco CMTS Routers 99
Prerequisites for DOCSIS 2.0 A-TDMA Modulation Profiles for the Cisco CMTS Routers 100
Restrictions for DOCSIS 2.0 A-TDMA Services 101
Cisco CMTS Router Downstream and Upstream Features Configuration Guidevi OL-27606-08
Contents
Information About DOCSIS 2.0 A-TDMA Services 102
Modes of Operation 103
Modulation Profiles 105
Benefits 106
How to Configure DOCSIS 2.0 A-TDMA Services 106
Creating Modulation Profiles 106
Creating a TDMA Modulation Profile 106
Creating a Mixed Mode Modulation Profile 108
Creating an A-TDMA Modulation Profile 109
Configuring the DOCSIS Mode and Profile on an Upstream 110
Monitoring the DOCSIS 2.0 A-TDMA Services 112
Displaying Modulation Profiles 112
Displaying Cable Modem Capabilities and Provisioning 113
Configuration Examples for DOCSIS 2.0 A-TDMA services 114
Creating Modulation Profiles Examples 114
Example: DOCSIS 1.0/DOCSIS 1.1 TDMA Modulation Profiles 114
Example: Mixed TDMA/A-TDMA Modulation Profiles 115
Example: DOCSIS 2.0 A-TDMA Modulation Profiles 115
Assigning Modulation Profiles to Upstreams Examples 116
Example: Assigning DOCSIS 1.0/DOCSIS 1.1 TDMA Modulation Profiles 116
Example: Assigning Mixed TDMA/A-TDMA Modulation Profiles 117
Example: Assigning DOCSIS 2.0 A-TDMA Modulation Profiles 118
Additional References 119
Feature Information for DOCSIS 2.0 A-TDMA Modulation Profiles for the Cisco CMTS
Routers 121
C H A P T E R 6 DOCSIS 3.0 Downstream Bonding for Bronze Certification 123
Prerequisites for DOCSIS 3.0 Downstream Bonding for Bronze Certification 124
Restrictions for DOCSIS 3.0 Downstream Bonding for Bronze Certification 125
Information About DOCSIS 3.0 Downstream Bonding for Bronze Certification 125
Receive Channel Profile 126
Receive Channel Configuration 126
RCC Template 126
Channel Assignment 126
Downstream Traffic Forwarding 127
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 vii
Contents
How to Configure RCC Encoding 127
Configuring an RCC Template 127
Configuring RCC Encoding 128
Assigning an RCC Template to a Cable Interface 130
Verifying the RCC Configuration 131
Verifying the MD-DS-SG Configuration 132
How to Configure Attribute Masks 132
Configuring Provisioned Attributes for a Cable Interface 134
Configuring Provisioned Attributes for a Modular Cable Interface 134
Configuring Provisioned Attributes for an Integrated Cable Interface 135
Configuring Provisioned Attributes for a Wideband Cable Interface 136
Verifying the Attribute-Based Service Flow Assignments 137
Enabling Verbose Reporting for Receive Channel Profiles 138
Configuration Example for an RCC Template 139
Additional References 140
Feature Information for DOCSIS 3.0 Downstream Bonding for Bronze Certification 141
C H A P T E R 7 Downstream Channel ID Assignment on the Cisco CMTS Routers 145
Prerequisites for Downstream Channel ID Assignment on the Cisco CMTS Routers 146
Information About Downstream Channel ID Assignment on the Cisco CMTS Routers 147
Manual Downstream Channel ID Assignment on the Cisco CMTS Routers 148
Automatic Downstream Channel ID Assignment on the Cisco CMTS Routers 149
How to Configure Downstream Channel ID Assignment on the Cisco CMTS Routers 150
Configuring Manual Downstream Channel ID Assignment 150
Configuring Automatic Downstream Channel ID Assignment 151
Additional References 153
Feature Information for Downstream Channel ID Assignment on the Cisco CMTS
Routers 154
C H A P T E R 8 Downstream Resiliency Bonding Group 155
Prerequisites for Downstream Resiliency Bonding Group 156
Restrictions for the Downstream Resiliency Bonding Group 156
Information About Downstream Resiliency Bonding Group 158
Finding a Best-Fit RBG for the Cable Modem 158
How to Configure Downstream Resiliency Bonding Group 159
Cisco CMTS Router Downstream and Upstream Features Configuration Guideviii OL-27606-08
Contents
Enabling Downstream Resiliency Bonding Group 159
Reserving a Resiliency Bonding Group for a Line Card 160
Verifying Downstream Resiliency Bonding Group Configuration 161
Verifying the Downstream Resiliency Bonding Group 161
Verifying a Reserved Resiliency Bonding Group 162
Wideband Modem Resiliency Versus Downstream Resiliency 162
Troubleshooting the Downstream Resiliency Bonding Group Configuration 165
Configuration Examples of the Downstream Resiliency Bonding Group Feature 166
Additional References 171
Feature Information for Downstream Resiliency Bonding Group 172
C H A P T E R 9 IGMP-Triggered Dynamic Channel Change Load Balancing for DOCSIS 2.0 Cable Modems 173
Prerequisites for IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 CMs 174
Restrictions for IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 CMs 175
Information About IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 CMs 175
Combined Optimization Technique 176
Deployment of the IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 and DOCSIS 3.0
CMs 177
Interaction of IGMP-Triggered DCC Load Balancing With DOCSIS Load Balancing 178
Interaction of IGMP-Triggered DCC Load Balancing With Fairness Across DOCSIS
Interfaces 178
DOCSIS 2.0 Multicast Enhancement for VDOC 179
How to Configure IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 CMs 180
Creating a Load Balancing Group 180
Creating a Load Balancing Rule 181
Creating a Load Balancing Policy 183
Configuring a Load Balancing Group 184
Verifying IGMP-Triggered DCC Load Balancing Operations 186
Additional References 188
Feature Information for IGMP-Triggered DCC Load Balancing for DOCSIS 2.0 CMs 189
C H A P T E R 1 0 IGMP-Triggered VDOC Broadcast Support on the Cisco CMTS Routers 191
Prerequisites for Configuring VDOC Broadcast 192
Restrictions for Configuring VDOC Broadcast 193
Information About Configuring VDOC Broadcast 193
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 ix
Contents
Inter Line Card RF Spanning 194
RF Spanning of Bonding Groups Carrying Static Multicast Traffic 194
RF Spanning of Remote Bonding Groups 195
RCC Template 197
How to Configure VDOC Broadcast 198
Configuring the Primary and Secondary Bonding Group 198
Configuring the RCC Template 199
Configuring the Multicast Static Group 201
How to Configure Inter Line Card RF Spanning 203
Configuring RF Spanning of Bonding Groups Carrying Static Multicast Traffic 203
Configuring RF Spanning of Remote Bonding Groups 204
Configuration Examples for VDOC Broadcast 206
Example: Configuring the Primary and Secondary Bonding Groups 206
Example: Configuring the RCC Template 207
Example: Configuring the Multicast Static Group 208
Configuration Examples for Inter Line Card RF Spanning 209
Example: RF Spanning of Bonding Groups Carrying Static Multicast Traffic 209
Example: RF Spanning of Remote Bonding Groups 210
Verifying VDOC Broadcast and Inter Line Card RF Spanning 211
Additional References 215
Feature Information for Configuring VDOC Broadcast 216
C H A P T E R 1 1 Load Balancing, Dynamic Channel Change, and Dynamic Bonding Change on the Cisco
CMTS Routers 219
Prerequisites 221
Prerequisites for Load Balancing 222
Prerequisites for Dynamic Channel Change for Load Balancing 222
Prerequisites for Dynamic Bonding Change for DOCSIS 3.0 Static Modem Count-Based
Load Balancing 223
Restrictions 223
Restrictions for Load Balancing 223
Restrictions for Dynamic Channel Change for Load Balancing 225
DCC Restrictions with N+1 Redundancy and Inter-Card Load Balancing 226
Restrictions for DOCSIS 3.0 Static Modem Count-Based Load Balancing 227
Cisco CMTS Router Downstream and Upstream Features Configuration Guidex OL-27606-08
Contents
Restrictions for Dynamic Bonding Change for DOCSIS 3.0 Static Modem Count-Based
Load Balancing 227
Restrictions for MRC-Only Cable Modems 228
Information on the Load Balancing on the Cisco CMTS 228
Feature Overview 228
DOCSIS 3.0 Static Modem Count-Based Load Balancing 229
Error Handling of Channel Assignment 231
Multiple Channel Load Balancing Operation 231
Using DOCSIS 3.0 Static Modem Count-Based Load Balancing With DBC 233
Using DBC to Change the Receive Channel Set 234
Using DBC to Change the Transmit Channel Set 234
Using DBC to Change the Downstream ID 234
Using DBC to Change the Security Association for Encrypting Downstream
Traffic 235
Using DBC to Change the Service Flow SID Cluster Assignments 235
Types of Load Balancing Operations 235
Methods to Determine When Interfaces Are Balanced 237
Modems Method 237
Utilization Method 238
Service-Flows Method 239
Using Both Static and Dynamic Load Balancing 240
Load Balancing Parameters 240
Load Balancing Groups 240
Support for 256 Legacy LBGs 242
Downstream Load Balancing Distribution with Upstream Load Balancing 242
Upstream Load Balancing for DOCSIS 3.0 Cable Modems in Single Upstream Mode 243
Disabling Upstream Load Balancing for DOCSIS 3.0 Modems 243
Disabling Upstream Load Balancing for DOCSIS 3.0 Modems 244
DOCSIS 3.0 Dynamic Load Balancing 244
Interaction with Spectrum Management 244
DOCSIS 2.0 Multicast Enhancement for VDOC 245
Benefits of Load Balancing 246
Exclude Cable Modems from Load Balancing Groups 246
How to Configure Load Balancing 247
Creating a Load Balancing Group 247
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xi
Contents
Creating a Load Balancing Rule 248
Troubleshooting Tips 249
Creating a Load Balancing Policy 249
Configuring a Load Balancing Group 250
Configuring the DOCSIS 3.0 Dynamic Load Balancing 251
Assigning Interfaces to a Load Balancing Group 252
Excluding Cable Modems from a Load Balancing Group 254
Disabling Load Balancing 256
Distributing Downstream Load Balancing with Upstream Load Balancing 256
Examples 257
How to Configure Dynamic Channel Change for Load Balancing 259
Configuring DCC for Load Balancing on the Cisco CMTS 259
Verifying Load Balancing Operations 260
Troubleshooting Tips 261
Examples 262
Verifying Dynamic Bonding Change for Load Balancing 263
Debugging Load Balancing 264
Extended Load Balance Debugging 264
Configuration Examples for Load Balancing 265
Example: Load Balancing Group (Static Load Balancing) 265
Example: Load Balancing Group (Passive Load Balancing) 265
Example: Load Balancing Group (Dynamic Load Balancing) 265
Example: Interface Configuration 266
Example: Configuration for Upstreams and Downstreams 266
Example: Configuring Dynamic Channel Change for Load Balancing 268
Additional References 270
Feature Information for Load Balancing, Dynamic Channel Change, and Dynamic Bonding
Change on the Cisco CMTS Routers 272
C H A P T E R 1 2 M-CMTS DEPI Control Plane 279
Prerequisites for M-CMTS DEPI Control Plane 280
Restrictions for M-CMTS DEPI Control Plane 281
Information About M-CMTS DEPI Control Plane 281
Benefits of M-CMTS DEPI Control Plane 282
DEPI Control Connections 282
Cisco CMTS Router Downstream and Upstream Features Configuration Guidexii OL-27606-08
Contents
DEPI Data Sessions 282
DEPI SSO 282
N+1 DEPI Redundancy 283
GigE Port-level Redundancy 284
Difference Between Manual DEPI and Control Plane DEPI Configuration 284
DEPI EQAM Statistics 284
How to Configure M-CMTS DEPI Control Plane 285
Configuring DEPI Control Plane on the M-CMTS Router 285
Configuring DEPI Control Plane on Cisco RFGW-10 289
Configuring N+1 DEPI Redundancy on the M-CMTS Router and Cisco RFGW-10 295
Configuring DLM on the M-CMTS Router 296
Disabling a DEPI Data Session on the M-CMTS Router 297
Configuration Examples for M-CMTS DEPI Control Plane 298
Example: DEPI Control Plane Configuration on the M-CMTS Router 299
Example: DEPI Control Plane Configuration on Cisco RFGW-10 299
Example: N+1 DEPI Redundancy Configuration on the M-CMTS Router 300
Example: GigabitEthernet Interface Configuration on the M-CMTS Router 300
Example: GigabitEthernet Interface Configuration on Cisco RFGW-10 300
Verifying M-CMTS DEPI Control Plane 301
Verifying DEPI Tunnel Information 301
Verifying DEPI Session Information 302
Verifying DLM Configuration Information 304
Additional References 304
Feature Information for M-CMTS DEPI Control Plane 306
C H A P T E R 1 3 Restricted/General Load Balancing and Narrowband Dynamic Bandwidth Sharing with
Downstream Dynamic Load Balancing 309
Prerequisites for Restricted/General Load Balancing andNarrowbandDynamic Bandwidth Sharing
with Downstream Dynamic Load Balancing 310
Restrictions for Restricted/General Load Balancing and NarrowbandDynamic Bandwidth Sharing
with Downstream Dynamic Load Balancing 312
Information About Restricted/General Load Balancing and Narrowband Dynamic Bandwidth
Sharing with Downstream Dynamic Load Balancing 313
Service-Based Load Balancing 313
RLBG/GLBG Assignment 315
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xiii
Contents
Channel Assignment 316
Upstream Load Balancing for DOCSIS 3.0 Cable Modems in Single Upstream Mode 322
Narrowband LB with DBS 323
Auto-generate DOCSIS 2.0 GLBG 323
Independent Upstream/Downstream Throughput Rules 323
How to Configure Restricted/General Load Balancing and Narrowband Dynamic Bandwidth
Sharing with Downstream Dynamic Load Balancing 324
Configuring DOCSIS 3.0 and 2.0 RLBG and DOCSIS 2.0 GLBG 325
Configuring DOCSIS 3.0 GLBG 328
Configuring a DOCSIS 3.0 General Load Balancing Group 328
Configuring Default Values of DOCSIS 3.0 Load Balancing Group 330
Configuring Cable Modems to RLBG or a Service Type ID 331
Configuring Rules and Policies 331
Troubleshooting Tips 332
Configuring Load Balancing Parameter for a Cable Modem Movement Failure 333
Creating and Configuring TLV type Tag 333
Configuration Examples for Restricted/General Load Balancing and Narrowband Dynamic
Bandwidth Sharing with Downstream Dynamic Load Balancing 335
Example: Configuring a Tag 335
Example: Disabling Load Balancing 336
Verifying Restricted/General Load Balancing and Narrowband Dynamic Bandwidth Sharing
with Downstream Dynamic Load Balancing 336
Additional References 341
Feature Information for Restricted/General Load Balancing and Narrowband Dynamic
Bandwidth Sharing with Downstream Dynamic Load Balancing 342
C H A P T E R 1 4 RSVP-Based Video on Demand Support Over DOCSIS 347
Prerequisites for Configuring RSVP-Based Video on Demand Support Over DOCSIS 348
Restrictions for Configuring RSVP-Based Video on Demand Support Over DOCSIS 348
Information About RSVP-Based Video on Demand Support Over DOCSIS 349
How to Configure RSVP-Based Video over DOCSIS 350
Configuring the RSVP Service Class 350
Displaying the RSVP-DOCSIS Flow Data 350
Additional References 351
Feature Information for RSVP-Based Video over DOCSIS 352
Cisco CMTS Router Downstream and Upstream Features Configuration Guidexiv OL-27606-08
Contents
C H A P T E R 1 5 S-CDMA and Logical Channel Support on the Cisco CMTS Routers 355
Prerequisites for S-CDMA and Logical Channel Support 356
Restrictions for S-CDMA and Logical Channel Support 357
Information About S-CDMA and Logical Channel Support 358
S-CDMA Services 358
Modulation Profiles 359
Benefits 360
Logical Channels 361
Spectrum Management on Logical Channels 361
Load Balancing on Logical Channels 362
How to Configure S-CDMA and Logical Channel Support 362
Creating Modulation Profiles 362
Creating a DOCSIS 2.0 S-CDMA Modulation Profile 362
Configuring a Global Modulation Profile 363
Creating a DOCSIS 3.0 S-CDMA Modulation Profile 364
Configuring the DOCSIS Mode and Profile on an Upstream 365
Configuring the Logical Channel Support 368
Monitoring the S-CDMA and Logical Channel Support 369
Displaying Modulation Profiles 369
Displaying Cable Modem Capabilities and Provisioning 370
Displaying the Logical Channel Support 370
Configuration Examples for S-CDMA and Logical Channel Support 372
Creating Modulation Profiles Examples 372
Example: DOCSIS 2.0 S-CDMA Modulation Profiles 372
Example: Global Modulation Profiles 373
Example: DOCSIS 3.0 S-CDMA Modulation Profiles 373
Assigning Modulation Profiles to Upstreams Examples 374
Example: Assigning DOCSIS 2.0 S-CDMA Modulation Profiles 374
Example: Assigning Global Modulation Profiles 375
Example: Assigning DOCSIS 3.0 S-CDMA Modulation Profiles 377
Example: Creating Logical Channels 377
Additional References 378
Feature Information for S-CDMA and Logical Channel Support on the Cisco CMTS Routers 380
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xv
Contents
C H A P T E R 1 6 Spectrum Management and Advanced Spectrum Management for the Cisco CMTS 383
Prerequisites for Spectrum Management and Advanced Spectrum Management 384
Restrictions for Spectrum Management 386
Shared Spectrum Groups 387
Cisco IOS Releases and Cable Interface Line Card Support 387
Dynamic Upstream Modulation 388
Fixed-Frequency Spectrum Groups with Advanced Spectrum Management 388
Limitations on Upstream Modulation Parameters for PacketCable VoIP Calls 388
N+1 Redundancy Support 389
Intelligent and Advanced Spectrum Management Support 389
Information About Spectrum Management 390
Spectrum Management Measurements 391
Signal and Carrier Noise Ratios 391
Differences Between the MER (SNR) and CNR (CNiR) Values 392
Additional Measurements 394
Upstream Signal Channel Overview 394
Upstream Segments and Combiner Groups 396
Frequency Management Policy 397
Noise Impairments 397
Spectrum Groups and Frequency Hopping 398
Guidelines for Spectrum Management 398
Guided and Scheduled Spectrum Management 399
Frequency Hopping Capabilities 399
Dynamic Upstream Modulation (MER [SNR]-Based) 401
Feature Overview 401
Criteria for Switching Modulation Profiles 402
Input Power Levels 403
Intelligent and Advanced Hardware-Based Spectrum Management 404
Intelligent Spectrum Management Enhancements 404
Advanced Spectrum Management Support Using the Cisco uBR10-MC5X20S/U/H
BPE 404
Benefits 406
Guided and Scheduled Spectrum Management Benefits 406
Intelligent and Advanced Spectrum Management Benefits 407
Cisco CMTS Router Downstream and Upstream Features Configuration Guidexvi OL-27606-08
Contents
How to Configure Spectrum Management 408
Guided and Scheduled Spectrum Management Configuration Tasks 408
Creating and Configuring Spectrum Groups 408
Assigning a Spectrum Group to One or More Upstream Ports 411
Configuring Shared Spectrum Groups (Fiber Node Groups) for DOCSIS 3.0 412
Configuring Dynamic Upstream Modulation (MER [SNR]-Based) 412
Verifying Frequency Hopping 416
Intelligent and Advanced Spectrum Management Configuration Tasks 419
Configuring and Assigning Spectrum Groups 419
Configuring Dynamic Upstream Modulation (CNR-Based) 419
Configuring Proactive Channel Management 421
Configuring Proactive Channel Management for Releases Prior to 12.3(13a)BC 422
Configuring Proactive ChannelManagement for Release 12.3(13a)BC, 12.2(33)SCC,
and Later 424
Verifying the Spectrum Management Configuration 427
Monitoring Spectrum Management 430
Using CLI Commands 431
Using SNMP 433
ccsSNRRequestTable 433
ccsSpectrumRequestTable 434
ccsSpectrumDataTable 435
ccsUpSpecMgmtTable 435
ccsHoppingNotification 437
Configuration Examples 438
Spectrum Group and Combiner Group Examples 438
Example: Verifying Spectrum Group Creation 438
Example: Time-Scheduled Spectrum Group 438
Example: Verifying Spectrum Group Configuration 439
Example: Determining the Upstream Ports Assigned to a Combiner Group 439
Example: Combiner Group 440
Example: Other Spectrum Management Configurations 441
Dynamic Upstream Modulation Examples 442
Verifying Your Settings 443
Example: Modulation Profiles 443
Example: Input Power Level 444
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xvii
Contents
Advanced Spectrum Management Configuration Examples 445
Example: Advanced Spectrum Management for the Cisco uBR7200 Series Router 445
Example: Advanced Spectrum Management for the Cisco uBR10012 Router 448
Additional References 449
Feature Information for Spectrum Management and Advanced Spectrum Management on
CMTS 451
C H A P T E R 1 7 Support for Extended Upstream Frequency Ranges 457
Prerequisites for Extended Upstream Frequency Ranges 458
Restrictions for Extended Upstream Frequency Ranges 458
Information About Extended Upstream Frequency Ranges 458
Frequency Ranges Currently in Use 459
Extended Frequency Support for Downstreams 459
Extended Frequency Support for Upstreams 459
How to Configure the Upstream Frequency Range 460
Configuring DOCSIS Upstream Frequencies 460
Configuring Extended DOCSIS Upstream Frequencies for Japan 462
Configuring EuroDOCSIS Upstream Frequencies 464
Configuration Examples for Extended Upstream Frequency Ranges 465
Example: Configuring North American (DOCSIS) Frequency Range 465
Example: Configuring Japanese Frequency Range 467
Example: Configuring European (EuroDOCSIS) Frequency Range 470
Additional References 473
C H A P T E R 1 8 Upstream Bonding Support for D-PON on the Cisco CMTS Routers 475
Prerequisites for Upstream Bonding Support for D-PON 475
Restrictions for Upstream Bonding Support for D-PON 476
Information About Upstream Bonding Support for D-PON 477
D-PON on Upstream Scheduling 478
How to Configure Upstream Bonding Support for D-PON 478
Verifying the Upstream Bonding Support for D-PON 479
Additional References 480
Feature Information for Upstream Bonding Support for D-PON on the Cisco CMTS
Routers 481
Cisco CMTS Router Downstream and Upstream Features Configuration Guidexviii OL-27606-08
Contents
C H A P T E R 1 9 Upstream Channel Bonding 483
Prerequisites for Upstream Channel Bonding 484
Restrictions for Upstream Channel Bonding 484
Information About Upstream Channel Bonding 485
Multiple Transmit Channel Mode 486
Multiple Receive Channel Mode 486
Dynamic Range Window and Transmit Power Levels for Upstream Channel Bonding 487
Extended Transmit Power 487
Reduced Transmit Channel Set 489
T4 Multiplier 489
Fiber Node Configuration for Upstream Channel Bonding 489
New TLVs for Upstream Channel Bonding 490
Upstream Weighted Fair Queuing 491
Class-Based Weighted Fair Queuing 491
Activity-Based Weighted Fair Queuing 491
Custom Weight for Service Flow Priorities 491
Upstream Scheduler and Service Flows 492
Distribution of Traffic across all Channels in a USBG 493
DOCSIS 3.0 Load Balancing with USBG Smaller than Cable Modem Capabilities 493
Cisco uBR10-MC5X20H Line Card Rate Limiting 494
SID Tracking 494
Service ID Clusters 494
How to Configure Upstream Channel Bonding 495
Enabling MTC Mode on a Cisco CMTS Router 495
Default MTC Mode Configuration on a Cisco CMTS Router 495
Enabling MTC Mode for All CMs 495
Creating a Bonding Group 496
Adding Upstream Channels to a Bonding Group 497
Adding Upstream Channel Ports to a Fiber Node 498
Configuring the Class-Based Weighted Fair Queuing 499
Configuring the Activity-Based Weighted Fair Queuing 500
Configuring Custom Weights for Service Flow Priorities 501
Configuring the SID Cluster 501
Configuring the Channel Timeout for a Cable Modem 503
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xix
Contents
Configuring Cable Upstream Resiliency 504
Configuring Rate Limiting on the Cisco uBR10-MC5X20H Line Card 505
Enabling Upstream Related Events for CM Status Reports 505
Modifying the Bonding Group Attributes 506
Modifying the Ranging Poll Interval on Upstream Channels 507
Configuring the Reduced Channel Set Assignment 508
Configuring DOCSIS Extended Transmit Power Feature 509
Troubleshooting Tips 509
Configuration Example for Upstream Channel Bonding 510
Example: Enabling MTC Mode for a Single CM Using the CM Configuration File 511
Verifying the Upstream Channel Bonding Configuration 511
Verifying Weighted Fair Queuing for Upstream Service Flows 515
Verifying Rate Limiting for Upstream Bonded Service Flows 515
Verifying Extended Power Transmission 516
Additional References 516
Feature Information for Upstream Channel Bonding 518
C H A P T E R 2 0 Upstream Scheduler Mode for the Cisco CMTS Routers 525
Prerequisites for the Upstream Scheduler Mode for the Cisco CMTS Routers 526
Restrictions for Upstream Scheduler Mode for the Cisco CMTS Routers 527
Information About Upstream Scheduler Mode for the Cisco CMTS Routers 527
Upstream Peak Traffic Rate 528
Upstream Bandwidth Request Rate Limiting 528
How to Configure Upstream Scheduler Modes 529
How to Configure Exempted Priority for BRRL feature 530
Additional References 531
Feature Information for Upstream Scheduler Mode for the Cisco CMTS Routers 532
C H A P T E R 2 1 Upstream Utilization Optimization on the Cisco CMTS Routers 535
Prerequisites for Upstream Utilization Optimization 536
Information about Upstream Utilization Optimization 537
How to Configure Upstream Utilization Optimization 537
Configuring Upstream Utilization Optimization Globally 537
Configuring Upstream Utilization Optimization Locally Per Upstream 538
Verifying Upstream Utilization Optimization Configuration 539
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Contents
Additional References 540
Feature Information for Upstream Utilization Optimization 541
C H A P T E R 2 2 Wideband Modem Resiliency 543
Prerequisites for Wideband Modem Resiliency 543
Restrictions for Wideband Modem Resiliency 544
Information About Wideband Modem Resiliency 544
CM-STATUS Messages 545
RF Channel Event Dampening Time 545
Response of CMTS to RF Impairment Recovery 545
Trigger Thresholds for Downstream Events 546
How to Configure Wideband Modem Resiliency 548
Specifying Trigger Thresholds for Downstream Events 548
Specifying Persistence Time for RF Channels 548
Changing Default CM-STATUS Configuration 549
Verifying Wideband Modem Resiliency 550
What to Do Next 551
Modifying CM-STATUS Reports for Events 552
Enabling SNMP Traps for Wideband Resiliency Events 553
Enabling Wideband Resiliency Trap Notifications 554
Setting the Trap Interval 555
Configuration Example for Wideband Modem Resiliency 555
Additional References 556
Feature Information for Wideband Modem Resiliency 557
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 xxi
Contents
Cisco CMTS Router Downstream and Upstream Features Configuration Guidexxii OL-27606-08
Contents
C H A P T E R 1Cable Modem Upstream RF Adaptation
First Published: June 13, 2011
The CableModemUpstreamRFAdaptation feature uses per cable modem physical layer statistics to identifyand automatically move cable modems to another logical upstream channel within the same physical port.This is to prevent unnecessary channel-wide parameter changes, which reduces throughput, disrupts trafficflow for all modems, and makes some modems to go offline in extreme cases.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest featureinformation and caveats, see the release notes for your platform and software release. To find informationabout the features documented in this module, and to see a list of the releases in which each feature issupported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://www.cisco.com/ is not required.
Contents
Prerequisites for Cable Modem Upstream RF Adaptation, page 2
Restrictions for Cable Modem Upstream RF Adaptation, page 3
Information About Cable Modem Upstream RF Adaptation, page 3
How to Configure Cable Modem Upstream RF Adaptation, page 5
Troubleshooting Tips, page 9
Verifying Cable Modem Upstream RF Adaptation, page 10
Configuration Examples for Cable Modem Upstream RF Adaptation, page 10
Additional References, page 13
Feature Information for Cable Modem Upstream RF Adaptation, page 13
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 1
http://tools.cisco.com/ITDIT/CFN/http://www.cisco.com/http://www.cisco.com/Prerequisites for Cable Modem Upstream RF Adaptation Multiple logical channels must be configured.
Logical channels should be enabled per upstream.
Logical channel 0 is the preferred primary logical channel, and logical channel 1 is the preferred secondarylogical channel. This increases interoperability with other CMTS applications such as load balancingand upstream channel bonding.
The table below shows the hardware compatibility prerequisites for this feature.
The hardware components introduced in a given Cisco IOS Release are supported in all subsequent releasesunless otherwise specified.
Note
Table 1: Cable Hardware Compatibility Matrix for Cable Modem Upstream RF Adaptation
Cable Interface CardsProcessor EnginePlatform
Cisco IOS Release 12.2(33)SCFand later releases
Cisco uBR10-MC5X20H
Cisco UBR-MC20X20V1
Cisco uBR-MC3GX60V2
Cisco IOS Release 12.2(33)SCFand later releases
PRE2
PRE4
Cisco IOS Release 12.2(33)SCHand later releases
PRE5
Cisco uBR10012 UniversalBroadband Router
Cisco IOS Release 12.2(33)SCFand later releases
Cisco uBR-MC88V3
Cisco IOS Release 12.2(33)SCFand later releases
NPE-G2
Cisco uBR7246VXR UniversalBroadband Router
Cisco IOS Release 12.2(33)SCFand later releases
Cisco uBR-MC88V
Cisco IOS Release 12.2(33)SCFand later releases
NPE-G2
Cisco uBR7225VXR UniversalBroadband Router
1 The Cisco UBR-MC20X20V cable interface line card has three variantsCisco UBR-MC20X20V-0D, Cisco UBR-MC20X20V-5D, and CiscoUBR-MC20X20V-20D. The Cisco UBR-MC20X20V-0D line card supports 20 upstreams and zero (no) downstreams. The Cisco UBR-MC20X20V-5D linecard supports 20 upstreams and 5 downstreams, and the Cisco UBR-MC20X20V-20D line card supports 20 upstreams and 20 downstreams.
2 The Cisco uBR-MC3GX60V line card is not compatible with PRE2.3 The Cisco uBR-MC88V cable interface line card is not compatible with NPE-G1. You must use NPE-G2 with the Cisco uBR-MC88V cable interface line
card.
Cisco CMTS Router Downstream and Upstream Features Configuration Guide2 OL-27606-08
Cable Modem Upstream RF AdaptationPrerequisites for Cable Modem Upstream RF Adaptation
Restrictions for Cable Modem Upstream RF Adaptation Logical channel 1 cannot be part of an upstream bonding group.
TheUpstreamChannel Bonding (USCB) feature coexists with the CableModemUpstreamRFAdaptationfeature; however, cable modems in the multiple transmits channel (MTC) mode are excluded.
Cable modems that use the multiple receive channel (MRC)mode withoutMTCmay participate in cablemodem upstream RF adaptation because these cable modems can be moved using the dynamic channelchange (DCC) method.
Advanced spectrum management is not supported in multiple logical channel configurations.
Dynamic channel-width configurations are not supported.
A pair of logical upstream channels configured with a mix of DOCSIS modes (i.e. SCDMA on logicalchannel 0 and ATDMA on logical channel 1) is supported, however, the CMTS will request that thecable modem uses the initialization technique 1 for the DCC.
Information About Cable Modem Upstream RF AdaptationThe Cable ModemUpstream RF Adaptation feature moves a single cable modem or a group of cable modemsto a more robust channel when a user-defined set of per cable modem PHY statistics does not meet a set ofuser-specified thresholds. Similarly, it releases a single cable modem or a group of cable modems from thesecondary channel when the user-defined set of per cable modem PHY statistics exceeds a set of user-specifiedthresholds.
The following relocation methods are used while moving a cable modem to and from the secondary logicalupstream channel:
UCC for DOCSIS 1.0 cable modems.
DCC initialization technique 2 for DOCSIS 1.1 and newer cable modems. Initialization technique 2performs periodic ranging. The cable modem is kept online and allowed to start on the new channel withperiodic ranging.
DCC initialization technique 1 for any configuration where at least one logical channel uses the SCDMADOCSIS mode. The initialization technique 1 broadcasts the initial ranging. The cable modem is keptonline and re-registration is avoided, but this technique requires completion of initial ranging.
The following PHY statistics are used while moving a cable modem to and from the secondary logical upstreamchannel:
Ranging burst Modulation Error Ratio (MER)
Data burst MER for JIB3-based line cards
Correctable and uncorrectable Forward Error Correction (FEC)
The cable modems to be relocated from the primary logical upstream channel to the secondary channel aremarked as downgrade candidates. Similarly, the cable modems to be relocated from the secondary logicalupstream channel to the primary channel are marked as upgrade candidates. Tracking individual cable modem
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 3
Cable Modem Upstream RF AdaptationRestrictions for Cable Modem Upstream RF Adaptation
statistics prevents a cable modem or a small group of cable modems from lowering the available bandwidthfor the larger population of cable modems.
Following are the step-by-step timer-based events that occur during RF adaptation:
1 General timer eventThe PHY statistics of the cable modems on the RF adapt-enabled channel arechecked. The cable modems that fail or exceed the set threshold are flagged as either downgrade or upgradecandidates.
2 Candidate timer eventThe PHY statistics of the cable modems that are flagged as downgrade or upgradecandidates are checked again to verify if the impairment still exists.
3 Relocation timer eventThe cable modems that continue to fail or exceed the threshold are relocated.
After a line card switchover, the cable modems remain online on either the primary or secondary logicalupstream channel depending on the state of the cable modem prior to the switchover. The upgrade anddowngrade candidate cable modems, and the cable modem movement history from primary to secondarylogical upstream channel and vice versa are not retained after a line card switchover. The Cable ModemUpstreamRFAdaptation feature is not affected by a PRE switchover and the candidate information and historyis retained during a PRE switchover.
The Cable Modem Upstream RF Adaptation feature is disabled by default. For information about how toenable this feature, see How to Configure Cable Modem Upstream RF Adaptation, on page 5.
Related CMTS Software FeaturesThe Cable Modem Upstream RF Adaptation feature via spectrum management integrates with and leveragesfrom the following CMTS software features:
Multiple Logical Channels, on page 4
CMTS PHY Measurement, on page 5
Multiple Logical Channels
The ability to use a multiple logical channel configuration to relocate cable modems with PHY impairmentsis a key capability of the Cable Modem Upstream RF Adaptation feature. In a cable modem upstream RFadaptation configuration, the logical channels are used as:
Logical Channel 0This is the default primary logical channel that cable modems registers on. Theprimary logical channel should be configured with performance options such as 64 QAM modulationprofile irrespective of the index value.
Logical Channel 1This is the default secondary logical channel. The secondary logical channel shouldbe configured with robust options, such as QPSK-based modulation profile irrespective of the indexvalue.
You can configure the primary and secondary logical channel. Whenmultiple logical channels are configured,the upstream-related commands are categorized into physical port level and logical channel level groups.Logical channel level commands use the format of cable upstream port logical-channel-index, where portdenotes the physical port number, and logical-channel-index denotes the logical channel index number.
The following logical channel-level configuration options have an impact on the Cable Modem Upstream RFAdaptation feature:
Cisco CMTS Router Downstream and Upstream Features Configuration Guide4 OL-27606-08
Cable Modem Upstream RF AdaptationRelated CMTS Software Features
DOCSIS mode. In the case of SCDMA, change in parameters like codes-per-minislot may also impactrobustness.
Modulation profile.
Equalization-coefficient (that is pre-equalization).
For more details on the Multiple Logical Channel feature, see S-CDMA and Logical Channel Support on theCisco CMTS Routers .
CMTS PHY Measurement
The CMTS PHY measurements collected on a per cable modem basis is used during RF adaptation. For acable modem upstream RF adaptation, the MER (also referred to as Signal-to-noise Ratio [SNR]), and FEC(both correctable and uncorrectable) measurements provide an accurate indication about the effect of anyPHY impairments on a single cable modem.
The Cable Modem Upstream RF Adaptation feature uses the following thresholds:
rf-adaptSets the RF adaptation percentage threshold.
snr-profilesSpecifies the MER (SNR) threshold in dB.
hysteresisSpecifies the hysteresis value.
corr-fecSpecifies the allowable number of correctable FEC errors for the upstream.
uncorr-fecSpecifies the allowable number of uncorrectable FEC errors for the upstream.
All the above thresholds are configured at the physical port level to ensure that the same collection ofthresholds is used for both upgrade and downgrade.
Note
How to Configure Cable Modem Upstream RF AdaptationThis section describes how to configure a physical upstream and its associated logical channels for cablemodem upstream RF adaptation.
Before You Begin
Multiple logical channels must be configured.
The cable modem upstream RF adaptation is not applicable for modems that are registered in MTCmode.Restriction
DETAILED STEPS
PurposeCommand or Action
Enables privileged EXEC mode.enableStep 1
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 5
Cable Modem Upstream RF AdaptationHow to Configure Cable Modem Upstream RF Adaptation
http://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_d30_scdma_lc_ps2209_TSD_Products_Configuration_Guide_Chapter.htmlhttp://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_d30_scdma_lc_ps2209_TSD_Products_Configuration_Guide_Chapter.htmlPurposeCommand or Action
Example:Router> enable
Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:Router# configure terminal
Step 2
(Optional) Sets the timer for cable modem upstream RF adaptation.cable rf-adapt timer general timeStep 3
Example:Router(config)# cable rf-adapt timer general1
general timeSpecifies the period when the RF adaptationprocess examines the physical layer statistics of all modems onRF adaptation-enabled upstream channels. The valid range isfrom 1 to 300 seconds.
(Optional) Sets the timer for cable modem upstream RF adaptation.cable rf-adapt timer candidate timeStep 4
Example:Router(config)# cable rf-adapt timercandidate 2
candidate timeSpecifies the period when the RF adaptationprocess examines the physical layer statistics of modems flaggedas downgrade or upgrade candidates, or both. The valid rangeis from 1 to 300 seconds.
(Optional) Sets the timer for cable modem upstream RF adaptation.cable rf-adapt timer relocation timeStep 5
Example:Router(config)# cable rf-adapt timerrelocation 300
relocation timeSpecifies the period when the RF adaptationprocess performs a single relocation of a candidate modem fromits current upstream channel to the appropriate destination. Thevalid range is from 1 to 300 seconds.
Enters interface configuration mode.interface cable {slot/cable-interface-index |slot/subslot/cable-interface-index}
Step 6
slotSlot where the line card resides.
Example:Router(config)# interface cable 8/0/0
Cisco uBR7225VXR routerThe valid value is 1 or 2.
Cisco uBR7246VXR routerThe valid range is from 3 to6.
Cisco uBR10012 routerThe valid range is from 5 to 8.
subslot(Cisco uBR10012 only) Secondary slot number of thecable interface line card. The valid subslot is 0 or 1.
cable-interface-indexDownstream port of the CiscouBR10-MC5X20 and Cisco uBR-MC88V line cards, or MACdomain index of the Cisco UBR-MC20X20V and CiscouBR-MC3GX60V line cards.
Cisco uBR7225VXR and Cisco uBR7246VXRroutersThe valid port value is 0 or 1.
Cisco CMTS Router Downstream and Upstream Features Configuration Guide6 OL-27606-08
Cable Modem Upstream RF AdaptationHow to Configure Cable Modem Upstream RF Adaptation
PurposeCommand or Action
Cisco uBR10012 routerThe valid range for the CiscoUBR-MC20X20V and Cisco uBR-MC5X20 line cards isfrom 0 to 4. The valid range for the CiscouBR-MC3GX60V line card is from 0 to 14.
Enables multiple logical channels on the physical upstream channelintended for RF adaptation.
cable upstreamportmax-logical-chans code
Example:Router(config-if)# cable upstream 0max-logical-chans 2
Step 7
portUpstream port. The valid range is from 0 to 3.
codeNumber of logical channels per port. The valid valuesare 1 and 2.
Enables RF adaptation on the physical upstream channel.cable upstream port rf-adaptStep 8
Example:Router(config-if)# cable upstream 0 rf-adapt
portUpstream port. The valid range is from 0 to 3.
(Optional) Sets the RF adaptation percentage threshold.cable upstream port threshold rf-adaptthreshold1-in-percent
Step 9
portUpstream port. The valid range is from 0 to 3.
Example:Router(config-if)# cable upstream 0threshold rf-adapt 25
rf-adaptSpecifies the ratio of candidate cable modems to totalnumber of upstream cable modems, which disables further RFadaptation.
threshold1-in-percentRF adapt disable threshold in percentage.The valid range is from 1 to 50.
You can bypass the RF adapt disable threshold by setting itto 0.
Note
(Optional) Specifies the MER (SNR) threshold in dB.cableupstreamportthresholdsnr-profilessnr-threshold1snr-threshold2
Step 10
snr-threshold1MER (SNR) threshold for the primarymodulation profile specified for the upstream. The valid rangeis from 5 to 35 dB, with a default value of 25 dB.
Example:Router(config-if)# cable upstream 0threshold snr-profiles 25 0
You can bypass the primary MER (SNR) threshold(snr-threshold1-in-db) by setting it to 0.
Note
snr-threshold2MER (SNR) threshold for the secondarymodulation profile specified for the upstream. The valid rangeis from 5 to 35 dB, with a default value of 25 dB. For the CableModem Upstream RF Adaptation feature, it is recommended toset this value to 0.
snr-threshold2 is ignored by the Cable ModemUpstream RF Adaptation feature.
Note
(Optional) Specifies the hysteresis value.cableupstreamportthresholdhysteresishysteresis-value
Step 11
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 7
Cable Modem Upstream RF AdaptationHow to Configure Cable Modem Upstream RF Adaptation
PurposeCommand or Action
hysteresis-valueHysteresis value. The valid range is from 0to 10 dB, with a default value of 3 dB.Example:
Router(config-if)# cable upstream 0threshold hysteresis 3
You can bypass the hysteresis threshold by setting thevalue to 0.
Note
(Optional) Specifies the allowable number of correctable FEC errorsfor the upstream.
cable upstreamportthreshold corr-fecfec-corrected
Example:Router(config-if)# cable upstream 0threshold corr-fec 2
Step 12
fec-correctedAllowable number of correctable FEC errorsfor the upstream, given as a percentage of total packets receivedon the upstream during the polling period. It is given as apercentage of total packets received on the upstream during thepolling period. The valid range is from 1 to 30 percent, with adefault value of 3 percent.
You can bypass the corr-fec threshold by setting thevalue to 0.
Note
(Optional) Specifies the allowable number of uncorrectable FEC errorsfor the upstream.
cable upstreamportthresholduncorr-fecfec-uncorrected
Step 13
Example:Router(config-if)# cable upstream 0threshold uncorr-fec 10
fec-uncorrectedAllowable number of uncorrectable FECerrors for the upstream, given as a percentage of total packetsreceived on the upstream during the polling period. The validrange is from 1 to 30 percent of total packets, with a default of1 percent.
You can bypass the uncorr-fec threshold by setting thevalue to 0.
Note
(Optional) Specifies the primary upstream logical channel and thesecondary upstream logical channel.
cable upstream port logical-channel-indexrf-adapt [primary | secondary]
Step 14
Example:Router(config-if)# cable upstream 0 0rf-adapt primary
portUpstream port. The valid range is from 0 to 3.
logical-channel-indexLogical channel index. The valid valuesare 0 and 1.
primarySets the logical channel as primary for RF adaptation.By default, the logical channel 0 is primary.
secondarySets the logical channel as secondary for RFadaptation. By default, the logical channel 1 is secondary.
When you set the primary channel, the secondarychannel is automatically set.
Note
Performs a no shutdown on logical channel 1.no cable upstream portlogical-channel-indexshutdown
Step 15
Cisco CMTS Router Downstream and Upstream Features Configuration Guide8 OL-27606-08
Cable Modem Upstream RF AdaptationHow to Configure Cable Modem Upstream RF Adaptation
PurposeCommand or Action
Example:Router(config-if)# no cable upstream 0 1shutdown
Exits the interface configurationmode and returns to privileged EXECmode.
end
Example:Router(config-if)# end
Step 16
What to Do Next
If you want to customize multiple logical channels, see S-CDMA and Logical Channel Support on the CiscoCMTS Routers.
Troubleshooting TipsFollowing are some scenarios that you may encounter while configuring or after configuring the CableModemUpstream RF Adaptation feature. Follow the recommended action to resolve these issue.
Cable Modem Does Not Downgrade to the Secondary Logical ChannelProblem A cable modem with PHY statistics less than the user-specified threshold is not downgraded to thesecondary logical channel.
Possible Cause The RF adaptation downgrade threshold has been met.
Possible Cause The RF adaptation downgrade threshold is exceeded while the cable modem is stillon the downgrade candidate list.
Possible Cause The RF adaptation downgrade threshold is exceeded after a group of cable modemsare moved to the secondary logical channel.
Solution Contact Cisco Technical Assistance Center (TAC).
Cable Modem Does Not Upgrade to the Primary Logical ChannelProblem A cable modem with PHY statistics greater than the user-specified threshold is not upgraded to theprimary logical channel.
Possible Cause The cable modem was upgraded or downgraded five times.
Possible Cause The SNR has not improved beyond the threshold and the hysteresis value.
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 9
Cable Modem Upstream RF AdaptationTroubleshooting Tips
http://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_d30_scdma_lc_ps2209_TSD_Products_Configuration_Guide_Chapter.htmlhttp://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_d30_scdma_lc_ps2209_TSD_Products_Configuration_Guide_Chapter.htmlSolution You can delete the cable modem history from the CMTS database using the clear cable modemdelete command.
Verifying Cable Modem Upstream RF AdaptationPurposeCommand
To verify the downgrade candidate cable modems.show cable rf-adapt downgrade-candidates
To verify the upgrade candidate cable modems.show cable rf-adapt upgrade-candidates
To verify the RF adaptation historyshow cable modem rf-adapt
Configuration Examples for Cable Modem Upstream RFAdaptation
This section provides configuration examples for the Cable Modem Upstream RF Adaptation feature:
Example: Configuring Cable Modem Upstream RF Adaptation on the CiscouBR10012 Router
The following example shows how to configure the Cable Modem Upstream RF Adaptation feature on theCisco uBR10012 router.
!interface Cable8/0/0load-interval 30downstream Modular-Cable 1/1/0 rf-channel 0 upstream 0-3cable mtc-modeno cable packet-cachecable bundle 1cable upstream max-ports 4cable upstream bonding-group 700upstream 0upstream 1upstream 2upstream 3attributes A0000000
cable upstream 0 connector 0cable upstream 0 frequency 13000000cable upstream 0 channel-width 6400000 6400000cable upstream 0 max-logical-chans 2cable upstream 0 threshold snr-profiles 20 0cable upstream 0 threshold corr-fec 0cable upstream 0 threshold uncorr-fec 0cable upstream 0 threshold rf-adapt 0cable upstream 0 rf-adaptcable upstream 0 0 docsis-mode scdmacable upstream 0 0 spreading-interval 16cable upstream 0 0 codes-per-minislot 16
Cisco CMTS Router Downstream and Upstream Features Configuration Guide10 OL-27606-08
Cable Modem Upstream RF AdaptationVerifying Cable Modem Upstream RF Adaptation
cable upstream 0 0 active-codes 112cable upstream 0 0 range-backoff 3 6cable upstream 0 0 modulation-profile 321cable upstream 0 0 attribute-mask 20000000no cable upstream 0 0 shutdowncable upstream 0 1 docsis-mode atdmacable upstream 0 1 minislot-size 1cable upstream 0 1 range-backoff 3 6cable upstream 0 1 modulation-profile 223cable upstream 0 1 attribute-mask 20000000no cable upstream 0 1 shutdownno cable upstream 0 shutdowncable upstream 1 connector 1cable upstream 1 frequency 20000000cable upstream 1 channel-width 3200000 3200000cable upstream 1 load-balance group 80cable upstream 1 docsis-mode scdmacable upstream 1 spreading-interval 16cable upstream 1 codes-per-minislot 4cable upstream 1 active-codes 112cable upstream 1 range-backoff 3 6cable upstream 1 modulation-profile 321cable upstream 1 attribute-mask 20000000no cable upstream 1 shutdowncable upstream 2 connector 2cable upstream 2 frequency 26400000cable upstream 2 channel-width 3200000 3200000cable upstream 2 power-level 1cable upstream 2 load-balance group 80cable upstream 2 docsis-mode scdmacable upstream 2 spreading-interval 16cable upstream 2 codes-per-minislot 4cable upstream 2 active-codes 112cable upstream 2 range-backoff 3 6cable upstream 2 modulation-profile 321cable upstream 2 attribute-mask 20000000no cable upstream 2 shutdowncable upstream 3 connector 3cable upstream 3 frequency 32600000cable upstream 3 channel-width 3200000 3200000cable upstream 3 power-level 1cable upstream 3 load-balance group 80cable upstream 3 docsis-mode scdmacable upstream 3 spreading-interval 16cable upstream 3 codes-per-minislot 4cable upstream 3 active-codes 112cable upstream 3 range-backoff 3 6cable upstream 3 modulation-profile 321cable upstream 3 attribute-mask 20000000no cable upstream 3 shutdowncable sid-cluster-group num-of-cluster 2cable sid-cluster-switching max-request 1
...
...
Example: Configuring Cable Modem Upstream RF Adaptation on the CiscouBR7200 Router
The following example shows how to configure the Cable Modem Upstream RF Adaptation feature on theCisco 7200 router.
!interface Cable1/1load-interval 30downstream Integrated-Cable 1/1 rf-channel 0-3 upstream 0-3cable mtc-modeno cable packet-cache
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 11
Cable Modem Upstream RF AdaptationExample: Configuring Cable Modem Upstream RF Adaptation on the Cisco uBR7200 Router
cable bundle 2cable upstream max-ports 4cable upstream 0 connector 4cable upstream 0 frequency 20000000cable upstream 0 channel-width 6400000 6400000cable upstream 0 max-logical-chans 2cable upstream 0 threshold snr-profiles 26 0cable upstream 0 threshold corr-fec 5cable upstream 0 threshold uncorr-fec 2cable upstream 0 threshold hysteresis 4cable upstream 0 threshold rf-adapt 0cable upstream 0 rf-adaptcable upstream 0 0 docsis-mode atdmacable upstream 0 0 minislot-size 4cable upstream 0 0 range-backoff 3 6cable upstream 0 0 modulation-profile 221cable upstream 0 0 attribute-mask 20000000no cable upstream 0 0 shutdowncable upstream 0 1 docsis-mode atdmacable upstream 0 1 minislot-size 4cable upstream 0 1 range-backoff 3 6cable upstream 0 1 modulation-profile 222cable upstream 0 1 attribute-mask 20000000no cable upstream 0 1 shutdownno cable upstream 0 shutdowncable upstream 1 connector 5cable upstream 1 frequency 26600000cable upstream 1 channel-width 3200000 3200000cable upstream 1 docsis-mode atdmacable upsteram 1 minislot-size 4cable upstream 1 range-backoff 3 6cable upstream 1 modulation-profile 321cable upstream 1 attribute-mask 20000000no cable upstream 1 shutdowncable upstream 2 connector 6cable upstream 2 frequency 30000000cable upstream 2 channel-width 3200000 3200000cable upstream 2 docsis-mode atdmacable upsteram 2 minislot-size 4cable upstream 2 range-backoff 3 6cable upstream 2 modulation-profile 221cable upstream 2 attribute-mask 20000000no cable upstream 2 shutdowncable upstream 3 connector 7cable upstream 3 frequency 33500000cable upstream 3 channel-width 3200000 3200000cable upstream 3 docsis-mode atdmacable upsteram 3 minislot-size 4cable upstream 3 range-backoff 3 6cable upstream 3 modulation-profile 221cable upstream 3 attribute-mask 20000000no cable upstream 3 shutdownend
Example: Non-Default Timer ConfigurationThe following example shows how to configure non-default timer configuration.
Router# show running-config | in timercable rf-adapt timer general 60cable rf-adapt timer candidate 15cable rf-adapt timer relocation 5
Cisco CMTS Router Downstream and Upstream Features Configuration Guide12 OL-27606-08
Cable Modem Upstream RF AdaptationExample: Non-Default Timer Configuration
Additional ReferencesRelated Documents
Document TitleRelated Topic
Cisco IOS Master Commands List, All ReleasesCisco IOS commands
http://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.htmlCisco IOS CMTSCable Command Reference
CMTS cable commands
Technical Assistance
LinkDescription
http://www.cisco.com/cisco/web/support/index.htmlThe Cisco Support and Documentation websiteprovides online resources to download documentation,software, and tools. Use these resources to install andconfigure the software and to troubleshoot and resolvetechnical issues with Cisco products and technologies.Access to most tools on the Cisco Support andDocumentation website requires a Cisco.com user IDand password.
Feature Information for Cable Modem Upstream RF AdaptationUse Cisco Feature Navigator to find information about platform support and software image support.Cisco Feature Navigator enables you to determine which software images support a specific software release,feature set, or platform. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. Anaccount on http://www.cisco.com/ is not required.
The below table lists only the software release that introduced support for a given feature in a givensoftware release train. Unless noted otherwise, subsequent releases of that software release train alsosupport that feature.
Note
Cisco CMTS Router Downstream and Upstream Features Configuration Guide OL-27606-08 13
Cable Modem Upstream RF AdaptationAdditional References
http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.htmlhttp://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.htmlhttp://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.htmlhttp://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.htmlhttp://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.htmlhttp://www.cisco.com/cisco/web/support/index.htmlhttp://tools.cisco.com/ITDIT/CFN/http://www.cisco.com/Table 2: Feature Information for Cable Modem Upstream RF Adaptation
Feature InformationReleasesFeature Name
12.2(33)SCFCable Modem Upstream RFAdaptation
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Cable Modem Upstream RF AdaptationFeature Information for Cable Modem Upstream RF Adaptation
Feature InformationReleasesFeature Name
The Cable Modem Upstream RFAdaptation feature uses the percable modem physical layerstatistics to identify andautomaticallymove cablemodemsto another logical upstream channelwithin the same physical port toprevent unnecessary channel-wideparameter changes.
In Cisco IOSRelease 12.2(33)SCF,this feature was introduced on theCisco uBR10012 router and CiscouBR7200 series routers.
The following sections provideinformation about this feature:
Information About CableModem Upstream RFAdaptation, on page 3
How to Configure CableModem Upstream RFAdaptation, on page 5
Verifying Cable ModemUpstreamRFAdaptation, onpage 10
Configuration Examples forCable Modem Upstream RFAdaptation, on page 10
The following commands wereintroduced or modified: cablerf-adapt timer, cable upstreamrf-adapt(logical channel), cableupstream rf-adapt, cableupstream threshold rf-adapt,show cable modem rf-adapt,show cable rf-adapt, cableupstream threshold hysteresis,cable upstream threshold, showcablemodem, show cablemodemaccess-group, show cablemodemcalls, show cable modemconnectivity, show cable modemcounters, show cable modemdocsis version, show cablemodem domain-name, showcable modem errors, show cable
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Cable Modem Upstream RF AdaptationFeature Information for Cable Modem Upstream RF Adaptation
Feature InformationReleasesFeature Name
modem flap, show cable modemipv6, show cable modem mac,show cablemodemmaintenance,show cable modem offline, showcable modem phy, show cablemodem primary channel, showcable modem registered, showcable modem rogue, show cablemodem summary, show cablemodem type, show cable modemunregistered, show cablemodemvendor, show cable modemwideband.
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Cable Modem Upstream RF AdaptationFeature Information for Cable Modem Upstream RF Adaptation
C H A P T E R 2Configuring Downstream Cable InterfaceFeatures on the Cisco CMTS Routers
First Published: February 14, 2008
Last Updated:May 12, 2009
Cisco IOS Release 12.2(33)SCA integrates support for this feature on the Cisco CMTS routers. Thisfeature is also supported in Cisco IOS Release 12.3BC, and this document contains information thatreferences many legacy documents related to Cisco IOS 12.3BC. In general, any references to Cisco IOSRelease 12.3BC also apply to Cisco IOS Release 12.2SC.
Note
The cable interface in the Cisco universal broadband routers serves as the cable TV radio frequency (RF)interface, supporting downstream and upstream signals. The downstream signal is output as anintermediate-frequency (IF) signal suitable for use with an external upconverter. Your cable plant, combinedwith your planned and installed subscriber base, service offering, and external network connections, determinesthe combination of cable interfaces, network uplink line cards, and other components that you should use.
The Cisco IOS software command-line interface (CLI) can be used to configure the Cisco cable interfaceline card for correct operation on the hybrid fiber-coaxial (HFC) cable network. This chapter provides aconfiguration summary for the various downstream cable interface features available on a Cisco CMTSrouter. Details about some of these features can be found in other chapters of this book.
The configuration commands and examples in this chapter may show slot numbering or references toeither Cisco uBR7200 series or Cisco uBR10012 Universal Broadband Routers. However, the featurescan be configured on either platform. Use the slot numbering appropriate for your CMTS routerconfiguration.
Note
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest featureinformation and caveats, see the release notes for your platform and software release. To find informationabout the features documented in this module, and to see a list of the releases in which each feature issupported, see the Feature Information Table at the end of this document.
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Use Cisco Feature Navigator to find information about platform support and Cisco software image support.To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://www.cisco.com/ is not required.
Contents
Prerequisites for Configuring Downstream Cable Interfaces on the Cisco CMTS Routers, page 18
Activating Downstream Cable Address Resolution Protocol Requests, page 19
Activating Downstream Ports, page 21
Assigning the Downstream Channel ID, page 22
Traffic Shaping, page 23
Configuring Downstream Rate Limiting and Traffic Shaping, page 24
Setting the Downstream Helper Address, page 25
Setting the Downstream Interleave Depth, page 26
Setting the Downstream Modulation, page 27
Setting the Downstream MPEG Framing Format, page 28
Setting Downstream Traffic Shaping, page 28
Activating Host-to-Host Communication (Proxy ARP), page 30
Activating Packet Intercept Capabilities, page 31
Configuring Payload Header Suppression and Restoration, page 31
Setting Optional Broadcast and Cable IP Multicast Echo, page 32
Cable Interface Configuration Examples, page 34
Prerequisites for Configuring Downstream Cable Interfaces onthe Cisco CMTS Routers
The configuration of downstream cable interface features is supported on the Cisco CMTS routers in CiscoIOS Release 12.3BC and 12.2SC. The table below shows the hardware compatibility prerequisites for thisfeature.
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersPrerequisites for Configuring Downstream Cable Interfaces on the Cisco CMTS Routers
http://tools.cisco.com/ITDIT/CFN/http://www.cisco.com/http://www.cisco.com/Table 3: Configuring Downstream Cable Interfaces on the Cisco CMTS Routers Hardware Compatibility Matrix
Cable Interface CardsProcessor EngineCMTS Platform
Cisco IOS Release 12.2(33)SCA
CiscouBR10-MC5X20S/U/H
Cisco IOS Release 12.2(33)SCA
PRE-2
Cisco IOS Release 12.2(33)SCHand later releases
PRE5
Cisco uBR10012 UniversalBroadband Router
Cisco IOS Release 12.2(33)SCA
Cisco uBR-MC28U/X
Cisco uBR-MC16U/X
Cisco IOS Release 12.2(33)SCA
NPE-G1
NPE-G2
Cisco uBR7246VXR UniversalBroadband Router
Cisco IOS Release 12.2(33)SCA
Cisco uBR-E-28U
Cisco uBR-E-16U
Cisco uBR-MC28U/X
Cisco uBR-MC16U/X
Cisco IOS Release 12.2(33)SCA
NPE-G1
Cisco uBR7225VXR UniversalBroadband Router
In most applications, default values for the commands used in these configuration steps are adequate toconfigure the Cisco CMTS router. You do not need to specify individual parameters unless you want todeviate from system defaults.
Note
Activating Downstream Cable Address Resolution ProtocolRequests
This configuration is required. Address Resolution Protocol (ARP) is an Internet protocol used to map IPaddresses to MAC addresses on computers and other equipment installed in a network. You must activateARP requests on the cable interface so that the Cisco uBR10000 series CMTS can perform IP address resolutionon the downstream path.
The default values for the commands used in this configuration step are adequate in most cases to configurethe Cisco uBR7200 series CMTS.
Note
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersActivating Downstream Cable Address Resolution Protocol Requests
DETAILED STEPS
PurposeCommand or Action
Enables privileged EXEC mode.enableStep 1
Example:Router> enable
Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:Router# configure terminal
Step 2
Enters cable interface configuration mode.interface cable5/0Step 3
Example:Router(config)# interface cable5/0
In this example, the interface is downstream port 0 on the cableinterface card installed in slot 1 of the Cisco uBR7200 seriesCMTS.
Enables ARP. This is the default.cable arp
Example:Router(config-if)# cable arp
Step 4
What to Do Next
To verify that cable ARP is activated, enter themore system:running-config command and look for thecable interface configuration information. If ARP is activated, it does not appear in this output. If ARP isdeactivated, it appears in the output asno cable arp.Router# more system:running-configBuilding configuration...
Current configuration:!interface cable5/0ip address 1.1.1.1 255.255.255.0no keepaliveno cable arpcable downstream annex Bcable downstream modulation 64qamcable downstream interleave-depth 32cable downstream symbol-rate 5056941cable upstream 0 frequency 15008000no cable upstream 0 shutdown
If you are having difficulty with verification, verify that you entered the correct port and cable interfaceline card slot number when you activated ARP and when you entered the show interface cable command.
Tip
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersActivating Downstream Cable Address Resolution Protocol Requests
Activating Downstream PortsTo activate a downstream port on a Cisco uBR7200 series cable interface card for digital data transmissionsover the HFC network, complete the steps in the following table.
DETAILED STEPS
PurposeCommand or Action
Enables privileged EXEC mode.enableStep 1
Example:Router> enable
Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:Router# configure terminal
Step 2
Enters cable interface configuration mode.interface cable5/0Step 3
Example:Router(config)# interface cable5/0
In this example, the interface is downstream port 0 on the cableinterface card installed in slot 1 of the Cisco uBR7200 seriesCMTS.
Activates downstream digital data from the Cisco uBR7200series router.
Enter the following commands:Step 4
cable downstream if-outputDeactivates downstream digital data. This commandmutes theIF output of the cable interface card and shuts down theinterfaces.
no cable downstream if-output
Example:Router(config-if)# cable downstream if-outputRouter(config-if)# no cable downstreamif-output
Places the downstream port in the admin up state.no shutdown
Example:Router(config-if)# no shutdown
Step 5
Returns to privileged EXEC mode.endStep 6
Example:Router(config-if)# endRouter#
This message is normal and does not indicate an error.
%SYS-5-CONFIG_I: Configured from console byconsole
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersActivating Downstream Ports
What to Do Next
To determine if the downstream carrier is active (up), enter the show controllers cable command for thedownstream port that you just configured. For National Television Standards Committee (NTSC) 6 MHzoperations, see the following example:Router# show controllers cable5/0 downstream
Cable5/0 Downstream is upFrequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 MspsFEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Assigning the Downstream Channel IDTo assign a numeric channel ID to the downstream port on the Cisco cable interface line card, use the followingcommand in cable interface configuration mode.Router(config-if)# cable downstream channel-id id
For Cisco IOS Release 12.2(33)SCB and later releases, the acceptable range is 1 to 255 (0 is reserved fornetwork management) and for releases prior to Cisco IOS Release 12.2(33)SCB, the acceptable range is0 to 255.
Note
The cable downstream channel-id command must be used with the following command:cable downstream frequency 54000000-1000000000 broadcast frequency - h
Note
These commands are used in instances where you want to send multiple downstream frequencies to a singleregion that contains CMs that can connect only to upstream ports on the same cable interface line card. Youmust configure unique channel IDs for each downstream that any CM is capable of receiving. The downstreamfrequency setting must match the setting on the upconverter.
After defining unique downstream IDs, test the CMs for correct operation. Cisco recommends that whenusing this feature, you re-test each subsequent software release of CM code to verify correct operationand to ensure reasonable acquisition time for new installations. Failure to use these commands in conjunctionor to test the involved CMs can result in customer service outages of indefinite duration.
Caution
Verifying the Downstream Channel IDTo verify the downstream channel ID, enter the show controllers cable command for the downstream portyou have just configured. See the following example:Router# show controllers cable5/0 downstream
Cable5/0 Downstream is upFrequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 MspsFEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4Downstream channel ID: 1
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersAssigning the Downstream Channel ID
Traffic ShapingTraffic shaping basically uses queues to limit data surges that can congest a network. The data is buffered andthen sent into the network in regulated amounts to ensure that the traffic fits within the expected traffic envelopefor the particular connection.
Traffic shaping reduces the chance that information must be retransmitted to hosts on the cable plant. Whencable modems (CMs) have rate limits established, the CMTS typically drops data packets to enforce the ratelimit. Dropping packets from the requesting CM causes the host sending the information to retransmit itsinformation, which wastes bandwidth on the network. If both hosts sending and requesting information areon the cable plant, the upstream bandwidth is wasted as well.
Traffic shaping allows the CMTS to perform upstream and downstream rate limiting on the DOCSIS upstreamand downstream channels. Rate limiting restricts the data rate to and from a CM; the MAC scheduler supportstraffic-shaping capabilities for downstream and upstream traffic. Rate limiting ensures that no single CMconsumes all of the channel bandwidth and allows a CMTS administrator to configure different maximumdata rates for different subscribers. Subscribers requiring higher sustained rates and willing to pay for higherrates can be configured with higher sustained rate limits in their CM DOCSIS configuration file over regularsubscribers, who pay less and get lower rate limits.
Each time a packet belonging to a flow is transmitted on an output channel, the token-bucket policer functionchecks the rate limit status of the flow, passing the following parameters:
Token bucket maximum sustained rate in bits per millisecond.
Token bucket depth (maximum transmit burst) in bits.
Length of current packet to be sent in bits.
Pointer to the flows token bucket.
Pointer to the flows token bucket last update time stamp.
Variable to return the milliseconds buffering delay in case the packet needs to be shaped.
Maximum buffering delay that the subsequent traffic shaper can handle in milliseconds.
Every flow has its own shaping buffer where rate-exceeded packets are typically held back in first-in/first-out(FIFO) order for later releases transmission.
Token bucket policing with shaping is the per-upstream default rate limiting setting at the CMTS. Shapingcan be enabled or disabled for the token-bucket algorithm.
Tip
Downstream Traffic ShapingThe CMTS supports basic downstream traffic shaping by effecting data rate limiting on a per-modem basis.A downstream traffic shaping feature called downstream rate limiting with type of service (ToS) bits extendsthat capability by allowing the CMTS administrator to configure the ToS byte to calculate the data rate for aspecified flow.
Downstream rate limiting with ToS bits enables you to partition downstream traffic for a CM into multipleclasses of service and multiple data rates by using the three precedence bits in the ToS byte in the IP header
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersTraffic Shaping
to specify a class of service assignment for each packet. Those packets with the precedence bit set in the ToSfield are given higher priority. Using the ToS byte, you can calculate the data rate for a specified flow, inaddition to the data rate configured on a per-CM basis. By specifying a maximum data rate for a particularToS, you can override the common maximum downstream data rate.
The administrator can override the maximum common downstream data rate limits by configuring the ToSbyte.
Packets that contain ToS bytes that have not been configured for downstream data rates continue to use thecommon data rate limits.
Configuring Downstream Rate Limiting and Traffic ShapingTo configure downstream traffic shaping, use the following command in cable interface configuration mode.
PurposeCommand
Enables or disables rate limiting and traffic shapingon the downstream of a cable interface.
Router(config-if)# [no] cable downstreamrate-limittoken-bucket [shaping] weighted-discard[expwt]
Using Cisco IOS Release 12.0(5)T1 or higher, the software adds downstream calendar queuing routinesand grant shaping application of the calendar queues.
Note
Effective with Cisco IOS Release 12.2(33)SCF, the cable downstream rate-limit command is notsupported for Cisco uBR-MC88U line card in Cisco IOS software.
Note
Details for key command usage are provided below:
To enable rate limiting on the given downstream port using the token bucket policing algorithm, issuethe cable downstream rate-limit token-bucket command.
To enable rate limiting on the given downstream port using the token bucket policing algorithm withtraffic shaping, issue the cable downstream rate-limit token-bucket shaping command.
To enable rate limiting on the given downstream port using the token bucket policing algorithm with aspecific traffic shaping time granularity, issue the cable downstream rate-limit token-bucket shapinggranularity 8 command. Acceptable values are 1, 2, 4, 8, or 16 msecs.
To enable rate limiting on the given downstream port using the token bucket policing algorithm with aspecific maximum traffic shaping buffering delay, issue the cable downstream rate-limit token-bucketshaping granularity 8 command. Acceptable values are 128, 256, 512, or 1028 msecs.
To remove rate limiting on the given downstream port, issue the cable downstream rate-limittoken-bucket command.
To enable rate limiting on the given downstream port using a weighted packet discard policing algorithmand to assign a weight for the exponential moving average of loss rate value, issue the cable downstreamrate-limit weighted-discard 3 command. Acceptable values are 1 to 4.
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Configuring Downstream Cable Interface Features on the Cisco CMTS RoutersConfiguring Downstream Rate Limiting and Traffic Shaping
Setting the Downstream Helper AddressSpecify an IP address of a Dynamic Host Configuration Protocol (DHCP) server where User Datagram Protocol(UDP) broadcast packets will be sent. You can specify a DHCP server for UDP broadcast packets from cableinterfaces, and a DHCP server for UDP broadcast packets from hosts. To set a downstream helper address,use the following commands in cable interface configuration mode.
DETAILED STEPS
PurposeCommand or Action
Set the downstream helper address to the DHCP server at IP address10.x.x.x for UDP broadcast packets from cable modems.
cable helper-address 10.x.x.x cable-modem
Example:Router(config-if)# cable helper-address10.x.x.x cable-modem
Step 1
Use the IP address of the DHCP server. Both 10.x.x.x and172.56.x.x are private ranges.
Note
Set the downstream helper address to the DHCP server at IP address172.56.x.x for UDP broadcast packets from hosts.
cable helper-address 172.56. x.xhost
Example:Router(config-if)# cable helper-address172.56.x.x host
Step 2
Verifying the Downstream Helper AddressTo verify the downstream helper address setting, enter the show running-config command and look for cablehelper-address in the cable interface configuration information:Router# show running-config
Building configuration...Current configuration:!interface cable5/0ip address 10.254.254.254 255.0.0.0no ip directed-broadcastcable helper-address 192.168.1.1no keepalive
Perform these steps if you are having difficulty with verification:
Step 1 Check the cables, upconverters, RF levels, and frequencies if the cable inter