Table Of Contents
Configuring Downstream Test Signals for the Cisco uBR7200 Series Cable Router
Feature Overview
Benefits
Related Features and Technologies
Related Documents
Supported Platforms
Supported Standards, MIBs, and RFCs
Configuration Tasks
Configuring Unmodulated Test Signals
Configuring PRBS Test Signals
Verifying Test Signal Output
Configuration Examples
Command Reference
cable downstream if-output
Syntax Description
Defaults
Command Modes
Command History
Usage Guidelines
Examples
Configuring Downstream Test Signals for the Cisco uBR7200 Series Cable Router
Feature Overview
This feature provides configuration commands that allow you to create downstream test signals. Both Pseudo Random Bit Stream (PRBS), and unmodulated carrier test signals are now supported.
A PRBS test signal is a random data pattern that has been modulated to look like a real data stream. An unmodulated test signal is a continuous sine wave that looks like a carrier wave on the downstream transmission.
Benefits
You can now create PRBS and unmodulated carrier tests directly. With earlier releases of IOS, you had to use test commands or indirect methods to perform these tests.
Related Features and Technologies
lists the IOS cable router features released in the IOS 12.0 timeframe.
Table 1 uBR7200 Series Cable Router Features Available Since 12.0 T
Available With:
|
Category
|
Feature
|
11.3(5)NA & 12.0(3)T
|
Cable Features
|
Feature Enhancements
|
11.3(6)NA
|
|
MC16 Modem Card
|
11.3(8)NA
|
|
Access List Support Enhancements
|
12.0(4)T
|
|
Downstream Channel ID Configuration
|
12.0(4)T
|
|
Multiple Service ID Support
|
12.0(4)T
|
|
Cable Modem and Host Subnet Addressing
|
12.0(5)T
|
|
Telephone Return
|
12.0(5)T
|
|
Time Server Functionality
|
12.0(7)T
|
|
Amplitude Averaging Compensation
|
12.0(7)XR
|
|
Cable Interface Bundling
|
12.0(7)XR
|
|
Enhanced Modem Status Display
|
12.0(7)XR
|
|
Show Interface Cable Command Verbose Enhancements
|
12.0(7)XR
|
|
IP Address Verification
|
12.0(7)XR
|
|
Registration Timeout Configuration
|
12.0(7)XR
|
|
Show Cable Modem Command Enhancements
|
12.0(7)XR
|
|
Modem Status Summary Enhancements
|
12.0(7)XR
|
|
Show Controller Command Enhancements
|
12.0(7)XR
|
|
Configuring Concatenation
|
12.0(7)XR
|
|
Virtual Private Network Support
|
12.0(7)XR
|
|
Blind Hopping Support on the MC16S Modem Card
|
12.0(7)XR
|
|
Signal-to-Noise Ratio Data Support
|
11.3(9)NA and 12.0(4)T
|
Cable QoS
|
QoS Profile Enforcement
|
12.0(4)T
|
|
Quality of Service for Voice
|
11.3(9)NA
|
Network Management
|
Upstream Traffic Shaping Feature
|
12.0(5)T
|
|
Enhanced-Spectrum Management
|
12.0(5)T
|
|
Downstream Rate Shaping with TOS bits
|
12.0(7)XR
|
|
Spectrum Management Using the MC16S Modem Card
|
12.0(7)XR
|
|
Downstream Test Signals Configuration
|
12.0(7)XR
|
Wireless Features
|
Point-to-Point Wireless Support
|
Related Documents
The uBR7200 series cable router is described in Voice, Video, and Home Applications Configuration Guide for Cisco IOS Release 12.0 and in the following online feature modules:
•
Cisco uBR7246 Universal Broadband Router Feature Enhancements
•MC16 Modem Card for uBR7200
•uBR7200 Series Access List Support Enhancements
•QoS Profile Enforcement for the Cisco uBR7200 Series Router
•Upstream Traffic Shaping Feature
•Configuring Downstream Channel IDs
•Telephone Return for the Cisco uBR7200 Series Cable Router
•Enhanced-Spectrum Management for the Cisco uBR7200 Series Cable Router
•Time Server Functionality
•Cable Interface Bundling for the Cisco uBR7200 Series Cable Router
•Quality of Service for Voice on the Cisco uBR7200 Series Cable Router
•Modem Status Enhancements for the Cisco uBR7200 Series Cable Router
•Load Sharing Support
•Cable Modem and Host Subnet Addressing
•MGX Resource Pool Management Hardware Diagnostics
•IP Address Verification for the Cisco uBR7200 Series Cable Router
•Configuring the Registration Timeout Value for the Cisco uBR7200 Series Cable Router
•Spectrum Management Using the MC16S Modem Card on the Cisco uBR7200 Series Cable Router
•Configuring Downstream Test Signals for the Cisco uBR7200 Series Cable Router (this feature)
•Configuring Concatenation on the Cisco uBR7200 Series Cable Router
•Point-to-Point Wireless Support for the Cisco uBR7200 Series Universal Broadband Router
•Blind Hopping Support on the MC16S Modem Card for the Cisco uBR7200 Series Cable Router
•Downstream Rate Shaping with TOS bits on the uBR7200 Series Cable Router
•Amplitude Averaging Compensation on the Cisco uBR7200 Series Cable Router
Supported Platforms
uBR7200 series
Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBs are supported by this feature.
RFCs
No new or modified RFCs are supported by this feature.
Configuration Tasks
See the following tasks to create PRBS and unmodulated carrier test signals. Each task in the list indicates if the task is optional or required.
•Configuring Unmodulated Test Signals (Required)
•Configuring PRBS Test Signals (Required)
Configuring Unmodulated Test Signals
Step
|
Command
|
Purpose
|
1
|
# router(config-if)# cable downstream if-output
continuous-wave
|
Generates an unmodulated continuous-wave signal on the downstream channel. The interface is shut down.
|
2
|
Router(config-if)# no cable downstream if-output
|
Stops sending test signals. Remember to re-enable the interface to resume normal operations.
|
Configuring PRBS Test Signals
Step
|
Command
|
Purpose
|
1
|
# router(config-if)# cable downstream if-output prbs
|
Generates a PRBS test signal on the downstream channel. The interface is shut down.
|
2
|
Router(config-if)# no cable downstream if-output
|
Stops sending test signals. Remember to re-enable the interface to resume normal operations.
|
Verifying Test Signal Output
Step 1 To verify the output of a continuous-wave test signal, use a spectrum analyzer on the downstream channel.
Step 2 To verify the output of a PRBS test signal, use a spectrum analyzer on the downstream channel.
Configuration Examples
None
Command Reference
This section documents the modified cable downstream if-output command. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.
cable downstream if-output
To create downstream test signals, use the cable downstream if-output interface configuration command. To stop sending test signals, use the no form of this command.
cable downstream if-output [continuous-wave | prbs]
no cable downstream if-output
Syntax Description
continuous-wave
|
Creates a downstream unmodulated carrier signal.
|
prbs
|
Creates a downstream PRBS carrier signal.
|
Defaults
Downstream carrier enabled.
Command Modes
Interface configuration
Command History
Release
|
Modification
|
11.3XA
|
This command was introduced.
|
12.0(7)XR
|
continuous-wave and prbs options added.
|
Usage Guidelines
The standard mode of operation is modulated signal output and the interface is active. For PRBS and continuous wave output, the selected interface will be shut down. The functioning of the no cable downstream if-output command has not changed (the interface is shut down).
Examples
router(config-if)# cable downstream if-output continuous-wave
router(config-if)# cable downstream if-output prbs
