Using the Cable Monitor Tool

Enabling the Cable Monitor

Configuration Modes

Security Considerations

Disabling the Cable Monitor

Accessing the Cable Monitor

Through the Cable Interface when the Cable Interface is Operational

Through the Serial Interface when the Cable Interface is Not Operational

Sample Pages

Home Page

Initialization Information

CPE State Information

Cable Interface Information

Performance Information

Debug Information Page

Using the Cable Monitor Tool

This appendix describes the Cisco uBR910 series DSU's Cable Monitor tool. The Cable Monitor is part of the DSU's onboard software that provides a web-based diagnostic tool for easy access to configuration and status information about the DSU, without requiring access to the DSU's command-line interface (CLI).

Note The Cable Monitor is available for the Cisco uBR910 series DSU in Cisco IOS Release 12.1(3)T and later releases.

Technicians and subscribers can access the tool in the following ways:

When the Cisco uBR910 series DSU has established connectivity with the CMTS over the cable interface, a service technician can use a web browser to remotely access the DSU and display the desired information.
When the cable network is not operational and the Cisco uBR910 series DSU is not online, the subscriber can access the tool with a PC on the LAN connected through the DSU's serial interface. Technicians can then prompt the user for the information they need to determine the source of the problem.

The Cable Monitor operates in two modes:

Basic Mode---In basic mode, the Cable Monitor displays the current status, as well as the results of the DSU's initialization routines (its power-on self-tests and its registration with the CMTS). This provides a quick status check of the DSU, as well as what stage of the initialization process is failing (if any). Basic mode also provides current run-time performance statistics.
Advanced Mode---In advanced mode, the Cable Monitor also displays status and configuration information about the DOCSIS MAC layer, the connected CPE devices, and the cable interface. If technicians have the proper login ID and password, this mode can also display advanced debug information that collects the output of the most commonly used troubleshooting commands.

Note The Cable Monitor is a read-only tool---it cannot modify or reconfigure the Cisco uBR910 series DSU. However, some of the information displayed in the advanced mode could be used to defeat the DSU's security. This information is available only to users who enter the enable password. Cisco recommends that an encrypted enable password be set on all Cisco uBR910 series DSUs deployed at subscriber sites. Passwords (along with SNMP community strings) should be different for each DSU, using a non-trivial pattern. If an enable password is not being used at a subscriber's site, the Cable Monitor should be run only in the basic mode.

The following sections describe the Cisco uBR910 series DSU's Cable Monitor:

Enabling the Cable Monitor

By default, the Cable Monitor is disabled. To allow technicians and subscribers to access the Cable Monitor, it must be enabled using the ip http global configuration command as follows:

Command Purpose

Step 1

ubr910(config)# ip http cable-monitor {basic | advance} [URL-IP-address URL-mask]

Immediately enable the Cable Monitor in either basic or advanced mode. Optionally specify the IP address and subnet mask for the Cable Monitor; these parameters also define the IP address pool used by the temporary DHCP server when the cable interface goes down.

Step 2

ubr910(config)# ip http port http-port

(Optional) Specify the TCP port number to use for web server (HTTP) requests. The default is the well-known web server port of 80.

	Command	Purpose
Step 1	ubr910(config)# ip http cable-monitor {basic \| advance} [URL-IP-address URL-mask]	Immediately enable the Cable Monitor in either basic or advanced mode. Optionally specify the IP address and subnet mask for the Cable Monitor; these parameters also define the IP address pool used by the temporary DHCP server when the cable interface goes down.
Step 2	ubr910(config)# ip http port http-port	(Optional) Specify the TCP port number to use for web server (HTTP) requests. The default is the well-known web server port of 80.

When the Cable Monitor is enabled, it also automatically enables the Cisco web server (giving the equivalent of the ip http server command). However, while the Cable Monitor is active, it disables all other access to the Cisco web server, preventing access to the CLI commands that are normally available when the Cisco web server is active. When the Cable Monitor is active, the Cisco web server can be used only for displaying the Cable Monitor pages.

Note If the Cable Monitor is not enabled on the Cisco uBR910 series DSU, Cisco recommends that the Cisco web server be disabled, using the no ip http server configuration command.

Configuration Modes

The ip http cable-monitor basic command enables the Cable Monitor and puts it in basic mode. In this mode, the Cable Monitor displays information only about the DSU's current status, which initialization routines were successfully completed, and cable performance statistics.

The ip http cable-monitor advance command enables the Cable Monitor and puts it in advanced mode. In this mode, the Cable Monitor displays the DSU's current status, the status of its initialization routines, the DSU's basic configuration, and the connected CPE devices. Users with the enable password can also view detailed debugging and troubleshooting information.

Note The advanced mode should not be used unless a secure encrypted enabled password is configured on the Cisco uBR910 series DSU.

By default, the Cable Monitor is configured with the IP address 192.168.100.1, which is a Class C address in the private IP address space reserved for private networks. If a device on the subscriber's private network is already using this IP address, use the URL-IP-address and URL-mask parameters to specify another IP address.

For example, to enable the Cable Monitor for advanced mode with the private IP address of 10.0.1.2 and the default HTTP port of 80, use the following command:

ip http cable-monitor advance 10.0.1.2 255.0.0.0

Note This command can be included in the Cisco IOS configuration file that is downloaded to the DSU at power-on during the DOCSIS provisioning.

Security Considerations

The Cable Monitor is a read-only tool that cannot change the configuration of the Cisco uBR910 series DSU. The debug page in advanced mode, however, does display information that could be used to defeat the DSU's security. This page is password-protected, requiring users to enter the enable password before displaying it; however, if an enable password has not been set, any user can display the debug page, which could reveal SNMP community strings and other configuration information.

Note The Cable Monitor must not be run in advanced mode when no enable password has been set because this would allow unauthorized users to view SNMP community strings and use SNMP to change the configuration.

For this reason, the following guidelines should be used when developing a security policy for the Cisco uBR910 series DSU:

If the Cable Monitor is being used in advanced mode, an encrypted enable password must be set. Otherwise, all users can view the debug page, which displays the Cisco uBR910 series DSU's complete configuration, including SNMP community strings.
If no enable password is set, which is normally done to disable all remote configuration of the Cisco uBR910 series DSU using Telnet, the Cable Monitor must be used only in basic mode.

Note Since downloading a Cisco IOS configuration file during the provisioning process automatically disables the console port, all remote configuration of the Cisco uBR910 series DSU using the CLI is disabled when an enable password is not set. In this situation, the only way to change the configuration is through SNMP or by resetting the Cisco uBR910 series DSU and uploading a new configuration file.

Disabling the Cable Monitor

To disable the Cable Monitor, use the ip http global configuration command as follows:

Command Purpose

Step 1

ubr910(config)# no ip http cable-monitor

Immediately disable the Cable Monitor, preventing any web server access to its web pages. This also automatically disables access to the Cisco web server (which is equivalent to giving the no ip http server command).

	Command	Purpose
Step 1	ubr910(config)# no ip http cable-monitor	Immediately disable the Cable Monitor, preventing any web server access to its web pages. This also automatically disables access to the Cisco web server (which is equivalent to giving the no ip http server command).

Note The Cable Monitor is disabled by default, so the no ip http cable-monitor command does not need to be included in the Cisco IOS configuration file that is downloaded to the DSU at power-on during the DOCSIS provisioning. However, the Cisco web server is enabled by default; if this is not desirable, include the no ip http server command in the Cisco IOS configuration file that is downloaded to the Cisco uBR910 series DSU.

When disabling the Cable Monitor, the console might display warning messages similar to the following:

% monitor-209.165.202.131 is not in the database.
% monitor-192.168.100.1 is not in the database.
% Range [209.165.202.131, 209.165.202.131] is not in the database.
% Range [192.168.100.1, 192.168.100.1] is not in the database.

These messages can be ignored because they are simply confirming that the IP addresses used for the Cable Monitor are no longer being used for that purpose.

Note The Cable Monitor can also be disabled by giving the no ip http server command, which disables all web server access. However, this is not recommended because it does not release the system resources that are specifically allocated to the Cable Monitor.

Accessing the Cable Monitor

The Cable Monitor can be accessed either through the cable interface (typically by technicians at the headend or the service provider's network operations center) or through the serial interface (typically by subscribers when the cable interface has gone down). See the following sections for more information.

Note You must be using a web browser that supports frames to access the Cable Monitor pages.

Through the Cable Interface when the Cable Interface is Operational

During normal operations---when the Cisco uBR910 series DSU is online and has connectivity with the CMTS through the cable interface---service technicians at the headend can access the Cable Monitor by doing the following:

Step 1 Start a web browser on a PC or workstation at the headend that has TCP/IP connectivity with the Cisco uBR910 series DSU.

Step 2 Access a URL with the IP address assigned to the cable interface on the Cisco uBR910 series DSU. This is typically an address in the service provider's IP address space.

For example, if the Cisco uBR910 series DSU has been assigned the IP address of 209.165.202.131 by the service provider, a technician at the headend would use the following URL to access the Cable Monitor:

http://209.165.202.131

If a port number other than the default of 80 has been assigned to the Cable Monitor, that port number must be included as part of the URL. For example, if the Cisco uBR910 series DSU has been assigned the IP address of 209.165.202.131 and a port number of 8080 by the service provider, a technician at the headend would use the following URL to access the Cable Monitor:

http://209.165.202.131:8080

Through the Serial Interface when the Cable Interface is Not Operational

When the Cisco uBR910 series DSU loses connectivity with the CMTS at the headend and detects that its cable interface is not operational, the DSU automatically switches into a diagnostic mode and does the following:

Activates a temporary DHCP server to assign IP addresses in the IP network that is defined by the IP address and subnet mask given with the ip http cable-monitor command (the default address pool is the Class C private network 192.168.100.0).
When a PC or other workstation connected through the Cisco uBR910 series DSU's serial interface makes a DHCP request, the DSU assigns an IP address and default gateway from this address space so that the PC can communicate with the Cable Monitor on the DSU.

Note The PC or workstation can be rebooted to force it to make a DHCP request. If using a Windows 95 or Windows 98 system, you can also use the winipcfg utility to send a DHCP release and renew request.

When the DSU detects any web server requests, it automatically redirects them to the Cable Monitor.
The DSU's DHCP server renews these IP addresses every 30 seconds as long as the cable interface is down.
When the cable interface is back up, the DSU returns to normal operation, using the configuration that existed before it switched into diagnostics mode.

When the cable interface is down, users at the subscriber site can use the following procedure to access the Cable Monitor to aid in troubleshooting the problem with the cable network:

Step 1 Access a PC connected to the subscriber LAN (this is the network connected to the access router that is connected to the serial interface on the Cisco uBR910 series DSU).

Step 2 If necessary, configure the PC so it obtains its IP address from a DHCP server---on Windows 95/98 computers, display the Network Control Panel, click the TCP/IP component for the computer's Ethernet adapter, click the IP Address tab under Properties, and click Obtain an IP address automatically.

Note Since most PCs are configured to use a DHCP server, this step is not usually necessary. However, if the PC has been assigned a static IP address, you should copy down its IP address and default gateway address before reconfiguring it to use a DHCP server.

Step 3 Reboot the PC so that it obtains an IP address from the Cisco uBR910 series DSU. If using Windows 95 or Windows 98, you can also do the following:

a. Bring up the Start menu and choose the Run menu option.

b. Enter winipcfg as the program to run.

c. When the winipcfg utility starts, select the computer's Ethernet adapter from its pull-down menu.

d. Click the Renew All button to obtain a new IP address from the Cisco uBR910 series DSU.

Step 4 Start a web browser on the PC and enter any arbitrary URL, such as http://anything. The Cisco uBR910 series DSU redirects the request to the Cable Monitor, which displays its home page.

Step 5 When the cable interface resumes normal operations, wait from 30 to 60 seconds to allow the PC to issue a DHCP renew request, or Windows 95 and 98 users can also use the winipcfg utility; you can also reboot the PC to force it to issue a DHCP renew request. If the PC normally uses static addressing, reconfigure it with the IP address and default gateway address it normally uses.

Sample Pages

Table B-1 lists each of the web pages displayed by the Cable Monitor, the modes in which the pages are displayed, and a short description of each page's information.

Table B-1: Cable Monitor Pages

Cable Monitor Page Modes Available Description

Home Page

Basic and Advanced

Displays current status and initialization information.

Initialization Information

Advanced Only

Displays more detailed initialization information.

CPE State Information

Advanced Only

Displays the basic configuration for the DSU.

Cable Interface Information

Advanced Only

Displays the current status and configuration of the cable interface.

Performance Information

Basic and Advanced

Displays current run-time performance statistics for the DSU.

Debug Information Page

Advanced Only (requires enable password)

Displays advanced configuration information.

Cable Monitor Page	Modes Available	Description
Home Page	Basic and Advanced	Displays current status and initialization information.
Initialization Information	Advanced Only	Displays more detailed initialization information.
CPE State Information	Advanced Only	Displays the basic configuration for the DSU.
Cable Interface Information	Advanced Only	Displays the current status and configuration of the cable interface.
Performance Information	Basic and Advanced	Displays current run-time performance statistics for the DSU.
Debug Information Page	Advanced Only (requires enable password)	Displays advanced configuration information.

The following sections describe each page in more detail.

Home Page

The Cable Monitor home page displays the current status of the Cisco uBR910 series DSU and summarizes the status of the DSU's registration process with the CMTS. Figure B-1 shows a typical home page.

Figure B-1: Cable Monitor Home Page

Note Figure B-1 shows the home page when the Cable Monitor is configured for advanced mode; in this mode, the left side displays links for all available pages. When the Cable Monitor is configured for basic mode, the left side displays only the link for the Performance Information page.

The Quick Status section of the home page summarizes the information that is displayed on the Initialization Information page, described in the next section.

Initialization Information

The Initialization Information page is available only in advanced mode and displays much of the same information shown in the Quick Status section of the Home Page. This information summarizes the DSU's power-on initialization and registration process using the following color codes:

Stages that passed are shown in green.
Any stage that failed is shown in red.
Stages that were not reached because of the failure of a previous stage are shown in black.

Figure B-2 shows a display for a Cisco uBR910 series DSU that has successfully registered and come online.

Figure B-2: Initialization Information Page

This page provides detailed information on the state changes when the Cisco uBR910 series DSU tries to establish communication and registration with the CMTS. All stages must show "Passed" before the DSU can come online.

Clicking on the name of the stage displays more information, if available, in the bottom half of the window. For example, clicking stage 11, "Download Configuration File state," displays the name of the configuration file that was downloaded to the DSU and the configuration parameters it contained.

The following is the normal progression of states that would be displayed if the Cisco uBR910 series DSU registers successfully with the CMTS:

Reset state---The DSU boots the Read-Only Memory (ROM) from its flash image, performs a self-test, initializes processor hardware, and boots the Cisco IOS release image stored in Flash memory.
Wait for link up state---The DSU checks the cable interface and determines whether a DOCSIS-compliant signal exists.
Downstream frequency scanning state---The DSU acquires a temporary downstream channel by matching the clock sync signal that is regularly sent out by the CMTS in the downstream frequency range. If this stage passes, click this link to display the following information:
- Downstream ID
- Downstream Frequency
- Downstream Symbol Rate
- Downstream QAM Mode
- Signal to Noise Ratio Estimate
- Downstream Lock Threshold
- Downstream Search
Wait for Upstream Channel Descriptor (UCD) state---The DSU waits for an Upstream Channel Descriptor (UCD) message from the CMTS and configures itself for the upstream frequency specified in that message. If this stage passes, click this link to display the following information:
- Upstream ID
- Upstream Frequency
- Mini-Slot Size
Wait for MAP state---The DSU waits for the next upstream bandwidth allocation map message (MAP), which are regularly sent from the CMTS, to find the next available shared request timeslot.
Power ranging first state---The DSU then uses the MAP timeslot to send a ranging request message to the CMTS, communicating the DSU's user ID (UID, which is its unique MAC address), using a temporary Service Identifier (SID) of 0 (zero) to indicate it has not yet been allocated an upstream channel. If this stage passes, click this link to display the following information:
- Ranging Offset
- Power Level
- Ranging Response SID Assigned
- Adjust Transmit Power
Power ranging second state---In reply to the DSU's ranging request, the CMTS sends a ranging response containing a temporary SID to be used for the initial DSU configuration and bandwidth allocation. As needed, the DSU adjusts its transmit power levels using the power increment value given by the CMTS in its ranging response message.
DHCP state---After the next MAP message broadcast, the DSU uses a shared require timeslot to invoke the Dynamic Host Configuration Protocol (DHCP) to establish IP connectivity with the TCP/IP network at the headend. The DHCP server sends a response with the following information:
- Assigned IP Address
- Network Mask
- TFTP Server IP Address
- Time Server IP Address
- Time Zone Offset
- Configuration File Name
Time of Day (TOD) state---The DSU configures itself for the specified IP address and gets the current date and time from the specified ToD server.
Security association state---Reserved for future use.
Download configuration file state---Using the TFTP protocol, the DSU downloads the specified DOCSIS configuration file and configures itself for the appropriate parameters. The DOCSIS configuration file contains the following parameters:
- Configuration File
- Network Access
- Maximum CPEs
- Class of Service information---Depending on the software image installed, up to four classes of service (CoS) are displayed. The following information is shown for each CoS:
Assigned SID

Max Downstream Rate

Max Upstream Rate

Upstream Priority

Min Upstream Rate

Max Upstream Burst

Privacy Enable
Registration state--- The DSU sends another registration request to the CMTS containing the CoS parameters given in the DOCSIS configuration file. The CMTS verifies that the DSU is using the appropriate CoS profile and converts the temporary SID into a data SID with a service class index that points to the applicable CoS profile.
Establish baseline privacy state---If BPI security has been enabled, the DSU negotiates the BPI parameters with the CMTS.
Maintenance state---The DSU enters the maintenance state, passing traffic on the cable interface to and from the CMTS, and responding to periodic maintenance messages from the CMTS.

CPE State Information

This page summarizes how the Cisco uBR910 series DSU has been configured at the MAC (physical) layer. Figure B-3 shows a typical CPE State Information page.

Figure B-3: CPE State Information Page

The following information is shown in the CPE State Information page:

Router Name---Shows the hostname assigned to the DSU.

IP Address---Shows the IP address assigned to the DSU's cable interface.

Net Mask---Shows the subnet mask for the cable interface.

MAC State---Indicates the current MAC layer state (during normal operation, this is "maintenance_state"). The following are the possible MAC layer states; they correspond to the states shown in the Initialization Information page:
- wait_for_link_up_state---Wait for Link Up state
- ds_channel_scanning_state---Downstream Channel Scanning state
- wait_ucd_state---Wait for UCD state
- wait_map_state---Wait for MAP state
- ranging_1_state---Ranging 1 state
- ranging_2_state---Ranging 2 state
- dhcp_state---DHCP state
- establish_tod_state---Time of Day state
- security_association_state---Security Association state
- configuration_file_state---Download Configuration File state
- registration_state---Registration state
- establish_privacy_state---Establish Privacy state
- maintenance_state---Maintenance state
Ranging SID---The SID assigned to the DSU by the CMTS.
Registered---Indicates whether the DSU successfully registered with the CMTS.
Privacy Established---Indicates whether the DSU established a BPI security session with the CMTS.
TFTP Server IP Address---Shows the IP address for the TFTP server that downloaded the DOCSIS configuration file to the DSU.
Time Server IP Address---Shows the IP address for the ToD server that provided the correct time-of-day to the DSU.
Time Zone Offset---Shows the time zone that the DSU has been configured to use.
Downstream Info---Click this link to display the following downstream characteristics:
- DS ID---The Downstream ID assigned to the DSU.
- DS Frequency---The frequency in MHz of the downstream assigned to the DSU.
- DS Symbol Rate---The symbol rate currently used on the downstream.
- DS QAM Mode---The bandwidth used on the downstream (64 QAM or 25 6QAM).
- Signal-to-Noise Ratio Estimate---The current SNR calculated for the downstream.
- DS Lock Threshold---The minimum SNR signal that the DSU requires to maintain a lock on the downstream signal.
Upstream Info---Click this link to display the following upstream characteristics:
- US ID---The Upstream ID assigned to the DSU.
- US Frequency---The frequency in MHz of the upstream assigned to the DSU.
- US Power Level---The target power level that the DSU should be using on the upstream.
- US Symbol Rate---The symbol rate currently used on the upstream.
- Ranging Offset---The delay correction, in units of 6.25 microseconds, that the DSU must apply to the CMTS Upstream Frame Time to synchronize upstream transmissions.
- Mini-Slot Size---The size of the DOCSIS mini-slots in units of 6.25 microseconds. Possible values are 2, 4, 8, 16, 32, 64, or 128.
- Change Count---The DOCSIS configuration change count, which tracks how many times the UCD parameters for a DSU have changed.
Configuration File Info---Click this link to display the contents of the DOCSIS configuration file that the DSU downloaded during its power-on provisioning.

Cable Interface Information

The Cable Interface Information page provides information on the Cisco uBR910 series DSU's cable interface and the quality of its signal. When the cable interface is not operational, the information provided is based on the live values last available.

Figure B-4 shows a typical Cable Interface page.

Figure B-4: Cable Interface Information Page

The following information is displayed on the Cable Interface page:

IP Address---The IP address assigned to the cable interface during DOCSIS provisioning.
Network Mask---The subnet mask assigned to the cable interface during DOCSIS provisioning.
MAC Address---The MAC (physical) layer address assigned to the DSU at the factory.
Signal Quality---The signal quality interprets the signal-to-noise ratio (SNR) as follows:
- Unreliable link (displayed in red)---SNR is 2,000 above the lock threshold; the link is likely to fail or go offline intermittently.
- Poor link (displayed in yellow)---SNR is 4,000 above the lock threshold; the link may occasionally go offline intermittently.
- Acceptable link (displayed in green)---SNR is 6,000 above the lock threshold; the link is good.
Signal to Noise Ratio Estimate---The current SNR value used to determine the Signal Quality.
Lock Threshold---The lock threshold value used to determine the Signal Quality.
Power Level---The current upstream power level that the DSU is using.

The following are errors encountered by the DSU at the MAC layer:

Mac Resets---The number of times that the DSU has reset its MAC layer.
Sync Lost---The number of times that the DSU has lost sync on the cable interface and the link has gone down.
Invalid Maps---The number of invalid MAPs that the DSU has received from the CMTS.
Invalid UCDs---The number of invalid UCDs that the DSU has received from the CMTS.
Invalid Ranging Response---The number of invalid ranging responses that the DSU has received from the CMTS.
Invalid Registration Response---The number of invalid registration responses that the DSU has received from the CMTS. Typically, an invalid registration response is due to either an authentication failure or a class of service failure.
T1 Timeouts---The number of times that the DSU timed out waiting for a UCD message from the CMTS.
T2 Timeouts---The number of times that the DSU timed out waiting for a broadcast ranging response from the CMTS.
T3 Timeouts---The number of times that the DSU timed out waiting for a ranging response from the CMTS.
T4 Timeouts---The number of times the DSU has reinitialized its MAC layer because it did not receive a Periodic Ranging opportunity from the CMTS.
Range Aborts---The number of times that the CMTS has instructed the DSU to abort a ranging attempt, typically because of excessive ranging or excessive power levels.

Performance Information

This page is available to all users and provides basic performance statistics for the Cisco uBR910 series DSU. Figure B-5 shows a typical Performance Information page.

Figure B-5: Performance Information Page

The following information is displayed on the Performance Information page:

System Uptime---The total time since the DSU was last reset or powered on.
CPU Utilization for 5 seconds---The average CPU load (0 to 100%) for the past 5 seconds.
CPU Utilization for 1 minute---The average CPU load (0 to 100%) for the past 1 minute.
CPU Utilization for 5 minutes---The average CPU load (0 to 100%) for the past 5 minutes.
Output Packets---The total number of MAC layer packets output on the upstream at the cable interface.
Output Bytes---The total number of bytes output on the upstream at the cable interface.
Output Queue---The current state of the output queue, shown as a ratio of the number of packets currently in the queue over the maximum size of the queue.
5 minute Output Rate---The average output rate over the past five minutes, in both bits per second and packets per second. For example, "10/40" shows that 10 packets are currently in the queue, which can hold 40 packets.
Input Packets---The total number of MAC layer packets received on the downstream at the cable interface.
Input Bytes---The total number of bytes output on the downstream at the cable interface.
Input Queue---The current state of the input queue, shown as a ratio of the number of packets currently in the queue over the maximum size of the queue. For example, "13/75" shows that 13 packets are currently in the queue, which can hold 75 packets.
5 minute Input Rate---The average input rate over the past five minutes, in both bits per second and packets per second.
Transmit Load---The current transmit load, shown as a ratio of the packets currently in the transmit buffer over the size of the buffer.
Receive Load---The current receive load, shown as a ratio of the packets currently in the receive buffer over the size of the buffer.

Debug Information Page

This page displays the output of the show tech-support command, which includes the output of the following CLI commands:

show version---Displays the hardware configuration, software image names and version, register settings, and the boot image.
show running-config---Displays the configuration the DSU is currently using.
show stacks---Displays the stack usage of the DSU's processes and interrupt routines, including the reason for the last system reboot.
show interfaces---Displays the status and configuration of the DSU's serial and cable interfaces.
show controllers---Displays the current state, configuration, and register information for each controller that the Cisco uBR910 series DSU uses to move data between the cable and Ethernet interfaces.
show controller c0 mac state---Displays the MAC layer configuration for the cable interface.
show region---Displays information about the memory regions in the DSU.
show process memory---Displays details about how tasks are using the DSU's memory.
show process cpu---Displays details about how tasks are using the DSU's CPU.
show buffers---Displays the usage of the different memory buffers on the DSU.

If an enable password has been set, the user must enter the level 15 user ID and password to access this page. If no enable password has been set, this page is accessible to all users.

Note Cisco recommends that an encrypted enable password be set on all Cisco uBR910 series DSUs that are deployed at subscriber sites. If an enable password is not being used at a subscriber's site, the Cable Monitor should not be enabled in advanced mode because the Debug Information page displays information, such as SNMP configuration information, that could create security concerns.

Figure B-6 shows a typical Debug Information page.

Figure B-6: Debug Information Page

Table of Contents

Using the Cable Monitor Tool