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Troubleshooting Tips for the Cisco uBR924 Cable Access Router 1

Troubleshooting Tips for the

Cisco uBR924 Cable Access Router

Feature Summary

This document describes the Cisco IOS troubleshooting commands that may be used by cable

service providers to verify communication between a Cisco uBR924 cable access router and other

peripheral devices installed in the HFC headend such as a Cisco uBR7200 series universal

broadband router, a DHCP server, and a TFTP server.

Benefits

The Cisco uBR924 cable access router troubleshooting system provides the following benefits:

• A MAC-layer system log file that provides a snapshot of detailed reasons why an interface might

reset, along with all the negotiations that occurred between the Cisco uBR924 cable access router

and the CMTS. Over 220 possible description fields exist in this log, which is displayed using the

show controllers cable-modem 0 mac log command from privileged EXEC mode.

• Debug does not need to be turned on in order to troubleshoot a Cisco uBR924 cable access router.

• The progression of normal data-over-cable communication events is clearly explained,

simplifying the resolution of faulty system connections.

• Troubleshooting and diagnostic tasks can be performed on the Cisco uBR924 from a remote

location using TELNET.

Restrictions

When using the Cisco uBR924 cable access router, keep the following restrictions and limitations in

mind:

• The Cisco uBR924 is able to implement multiple classes of service (CoS) on the cable interface;

however, separate CoS streams are only available when the cable access router is connected to a

headend that supports multiple CoS per cable access router. In addition, the configuration file

downloaded to the cable access router must specify the use of multiple classes of service.

• If the Cisco uBR924 cable access router is connected to a DOCSIS 1.0 headend that does not

support multiple CoS per cable access router, voice and data will be mixed, and voice traffic will

be transmitted on a best effort basis. This may cause poorer voice quality and lower data

throughput when calls are being made from the cable access router’s telephone ports. Voice

quality may also be affected when transmitting or downloading large files, or at other times when

network traffic is heavy.

Summary of content (74 pages)

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Troubleshooting Tips for the Cisco uBR924 Cable Access Router Feature Summary This document describes the Cisco IOS troubleshooting commands that may be used by cable service providers to verify communication between a Cisco uBR924 cable access router and other peripheral devices installed in the HFC headend such as a Cisco uBR7200 series universal broadband router, a DHCP server, and a TFTP server.
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Related Features and Technologies Note The Cisco uBR924 cable access router is typically configured at the headend. Most cable service operators do not permit local configuration at subscriber sites. Caution Before attempting to reconfigure a Cisco uBR924 cable access router at a subscriber site, contact your network management, provisioning manager, or billing system administrator to ensure remote configuration is allowed.
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Related Documents Prerequisites In order to use the Cisco uBR924 cable access router for data-over-cable applications, the following conditions must be met: • The Cisco uBR7200 series universal broadband router or other DOCSIS-based CMTS must be installed at the cable headend and configured. Refer to the Cisco uBR7246 Installation and Configuration Guide or the Cisco uBR7223 Installation and Configuration Guide for detailed information.
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List of Terms — Cisco Flash MIB — Bridge MIB — IF MIB — MIB-II • Cisco VoIP MIBs: — Cisco Voice IF MIB — Cisco Voice Dial-Control MIB — Cisco Voice Analog IF MIB — Cisco Dial-Control MIB • Radio Frequency Interface Specification—Developed by the Multimedia Cable Network System (MCNS) consortium. It defines the radio-frequency interface specification for high-speed data-over-cable systems. • CiscoWorks—Network management program for planning, troubleshooting, and monitoring Cisco internetworks.
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List of Terms Cable Modem Termination System (CMTS)—A termination system located at the cab le television system headend or distribution hub which provides complementary functionality to the cable modems, enabling data connectivity to a wide-are network. cable router—A modular chassis-based router optimized for data-over-CATV hybrid fiber-coaxial (HFC) applications. carrier—A signal on which another, lower-frequency signal is modulated in order to transport the lower-frequency signal to another location.
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List of Terms MAC layer—Media Access Control sublayer. Controls access by the cable access router to the CMTS and to the upstream data slots. MCNS—Multimedia Cable Network System Partners Ltd. A consortium of cable companies providing service to the majority of homes in the United States and Canada. This consortium has decided to drive a standard with the goal of having interoperable cable access routers. MSO—Multiple System Operator.
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List of Terms CMTS to Cable Modem Network Topology Figure 1 shows the physical relationship between the devices in the HFC network and the Cisco uBR924 cable access router. Figure 1 Sample Topology ISP WAN IP-related ATM, FDDI, 100BT... 100BT 100BT Proxy server Cisco uBR7246 CMTS Analog TV 100BT ISP @ home...
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Step 1—Understand How Basic Initialization Works Troubleshooting Steps To troubleshoot a malfunctioning cable modem, perform the following tasks: • • • • • Step 1—Understand How Basic Initialization Works Step 2—Connect to the Cisco uBR924 Step 3—Display the Cisco uBR924’s MAC Log File Step 4—Interpret the MAC Log File and Take Action (Optional) Step 5—Use Additional Troubleshooting Commands Step 1—Understand How Basic Initialization Works Before you troubleshoot a Cisco uBR924 cable access router, you
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Step 1—Understand How Basic Initialization Works Figure 2 Cable Modem Initialization Flowchart Power on 2 3 4 5 Scan for downstream channel Establish security Downstream sync established Security established Obtain upstream parameters Transfer operational parameters Upstream parameter acquired Transfer complete Start Ranging Register with the Cisco uBR7246 Ranging and auto adjust completed Registration complete Establish IP connectivety Baseline privacy initialization IP complete Base
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Step 2—Connect to the Cisco uBR924 . Table 1 Cable Modem Initialization Sequences and Events Sequence Event Description 1 Scan for a downstream channel and establish synchronization with the CMTS. The Cisco uBR924 acquires a downstream channel from the CMTS and saves the last operational frequency in non-volatile memory. The Cisco uBR924 tries to reacquire the saved downstream channel the next time a request is made.
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Step 3—Display the Cisco uBR924’s MAC Log File Step 3—Display the Cisco uBR924’s MAC Log File A MAC-layer circular log file is stored inside the Cisco uBR924. This file contains a history of the log messages such as state event activities and timestamps. This is the most valuable information for troubleshooting the cable interface. The MAC log file is displayed by entering the show controllers cable-modem 0 mac log command from privileged EXEC mode.
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Step 3—Display the Cisco uBR924’s MAC Log File 508144.390 508145.540 508146.120 508146.122 508146.124 508147.554 508147.558 508147.558 508147.622 508147.624 508148.058 508148.060 508148.062 508148.064 508148.066 508148.068 508148.070 508148.072 508148.562 508148.566 508148.568 508148.570 508148.572 508148.574 508148.576 508148.578 508148.580 508155.820 508155.824 508155.826 508155.826 508155.828 508165.892 508165.894 508165.896 508165.898 508165.900 508175.962 508175.964 508175.966 508175.968 508176.
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Step 4—Interpret the MAC Log File and Take Action 508178.318 508178.320 508178.322 508178.324 508178.326 508178.
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Step 4—Interpret the MAC Log File and Take Action Event 1—Wait for the Link to Come Up When the Cisco uBR924 cable access router is powered on and begins initialization, the first event that occurs is that the MAC layer informs the cable access router drivers that it needs to reset. The LINK_DOWN and LINK_UP fields are similar to the shut and no shut conditions on a standard Cisco interface. uBR924# show controllers cable-modem 0 mac log 528302.040 528302.042 528302.044 528302.046 528302.048 528308.
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Step 4—Interpret the MAC Log File and Take Action The search table is arranged so that the first frequencies tried are above 450 MHz. Because many CATV systems have been upgraded from 450 MHz to 750 MHz coaxial cable, digital channels have a high chance of being assigned in the new spectrum. The search table omits channels below 90 MHz and above 860 MHz since the DOCSIS specification does not mandate their coverage.
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Step 4—Interpret the MAC Log File and Take Action Event 5—Establish IP Connectivity After ranging is complete, the cable interface on the cable access router is UP. Now the Cisco uBR924 accesses a remote DHCP server to get an IP address. The DHCP request also includes the name of a file that contains additional configuration parameters, the TFTP server’s address and the Time of Day (TOD) server’s address.
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Step 4—Interpret the MAC Log File and Take Action Event 8—Transfer Operational Parameters After the DHCP and security operations are successful, the Cisco uBR924 downloads operational parameters via a configuration file located on the cable company’s TFTP server. The CMAC_LOG_DHCP_CONFIG_FILE_NAME field shows the filename containing the transmission parameters. 508177.164 CMAC_LOG_STATE_CHANGE 508177.166 CMAC_LOG_LOADING_CONFIG_FILE 508178.
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Step 5—Use Additional Troubleshooting Commands Event 11—Enter the Maintenance State As soon as the Cisco uBR924 has successfully completed the above events, it enters the operational maintenance state and is authorized to forward traffic into the cable network. 508178.322 CMAC_LOG_STATE_CHANGE maintenance_state Step 5—Use Additional Troubleshooting Commands You can use other show controllers and debug cable modem commands to troubleshoot different aspects of a Cisco uBR924 cable access router.
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Step 5—Use Additional Troubleshooting Commands Command Reference This section describes the commands used in Cisco IOS Release 12.0(5)T for troubleshooting the cable side of the Cisco uBR924 cable access router. The commands used to troubleshoot VoIP applications are documented in the Cisco IOS Release 12.0 command references.
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show controllers cable-modem show controllers cable-modem To display high-level controller information about a Cisco uBR924 cable access router, use the show controllers cable-modem command in privileged EXEC mode. show controllers cable-modem number Syntax Description number Controller number inside the Cisco uBR924. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.3 NA This command was first introduced.
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show controllers cable-modem Examples Following is sample output for the show controllers cable-modem 0 command: uBR924# show controllers cable-modem 0 BCM Cable interface 0: BCM3300 unit 0, idb 0x200EB4, ds 0x82D4748, regaddr = 0x800000, reset_mask 0x80 station address 0010.7b43.aa01 default station address 0010.7b43.
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show controllers cable-modem ehdr: 01 06 02 01 status=0x00 ehdr: 01 06 02 02 status=0x00 ehdr: 01 06 02 03 status=0x00 ehdr: 01 06 02 04 status=0x00 ehdr: 01 06 02 05 status=0x00 ehdr: 01 06 02 06 status=0x00 ehdr: 01 06 02 07 status=0x20 ehdr: 01 06 02 74 34 11 bd_index=0x0001 74 34 11 bd_index=0x0002 74 34 11 bd_index=0x0003 74 34 11 bd_index=0x0004 74 34 11 bd_index=0x0005 74 34 11 bd_index=0x0006 74 34 11 bd_index=0x0007 74 34 11 len=0x0000 hdr_len=0x0000 len=0x0000 hdr_len=0x0000 len=0x0000 hdr_len=
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show controllers cable-modem Table 2 Show Controllers Cable-Modem Field Descriptions (continued) Field Description data mcfilter MAC control filter for data. DS Downstream Broadcom receiver chip number and ID. US Upstream Broadcom transmitter chip number and ID. Tuner: status Current status of the tuner. Rx: tuner_freq Downstream frequency (in Hz) that the Cisco uBR924 searched for and found. symbol_rate Downstream frequency in symbols per second.
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show controllers cable-modem Table 2 Show Controllers Cable-Modem Field Descriptions (continued) Field Description TX PD ring: Indicates the memory location of the beginning of buffer information for the transmit packet descriptor ring. tx_head_pd Indicates current head packet descriptor. tx_tail_pd Indicates current tail packet descriptor. ehdr Extended MCNS header.
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show controllers cable-modem Related Commands Command Description show controllers cable-modem bpkm Displays information about the baseline privacy key management exchange between the Cisco uBR924 and the CMTS. show controllers cable-modem des Displays information about the Data Encryption Standard (DES) engine registers. show controllers cable-modem filters Displays the registers in the MAC hardware that are used for filtering received frames.
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show controllers cable-modem bpkm show controllers cable-modem bpkm To display information about the baseline privacy key management exchange between the Cisco uBR924 cable access router and the headend CMTS, use the show controllers cable-modem bpkm command in privileged EXEC mode. show controllers cable-modem number bpkm Syntax Description number Controller number inside the Cisco uBR924 cable access router. Defaults No default behavior or values.
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show controllers cable-modem bpkm Table 3 describes the fields shown in the display. Table 3 Show Controllers Cable-Modem bpkm Field Descriptions Field Description authorization wait time The number of seconds the Cisco uBR924 waits for a reply after sending the Authorization Request message to the CMTS.
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show controllers cable-modem des show controllers cable-modem des To display information about the Data Encryption Standard (DES) engine registers, use the show controllers cable-modem des command in privileged EXEC mode. show controllers cable-modem number des Syntax Description number Controller number inside the Cisco uBR924. Defaults No default behavior or values. Command Modes Privileged EXEC 28 Cisco IOS Release 12.
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show controllers cable-modem des Command History Release Modification 11.3 NA This command was first introduced.
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show controllers cable-modem des Table 4 Show Controllers Cable-Modem DES Field Descriptions (continued) Field Description ds_unencrypted_length Specifies the number of bytes that will be unencrypted at the beginning of the MAC frame. 0x0C means the first 12 bytes are not encrypted, which is what the DOCSIS Baseline Privacy specification calls for. us_des_key_table Table showing upstream DES keys. us_des_cbc_iv_table Table of upstream DES Cipher Block Chaining mode information.
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show controllers cable-modem filters show controllers cable-modem filters To display the registers in the MAC hardware that are used for filtering received frames, use the show controllers cable-modem filters command in privileged EXEC mode. show controllers cable-modem number filters Syntax Description number Controller number inside the Cisco uBR924. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.
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show controllers cable-modem filters Examples MAC and SID filter information is displayed in the following example: uBR924# show controllers cable-modem 0 filters downstream mac message processing: ds_mac_da_filters: filter_1=0010.7b43.aa01, filter_2=0000.0000.0000 filter_3=0000.0000.0000, filter_4=0000.0000.
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show controllers cable-modem filters Table 5 Show Controllers Cable-Modem Filters Field Descriptions (continued) Field Description Minislots per request Length of each registration request in mini-slots. burst_maps Maps the burst profiles saved in the BCM3037 registers to interval usage codes (IUCs). bytes_per_minislot_exp Number of bytes per expansion mini-slot. ticks_per_minislot Number of time ticks (6.25-microsecond intervals) in each upstream mini-slot.
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show controllers cable-modem lookup-table show controllers cable-modem lookup-table To display the mini-slot lookup table inside a Cisco uBR924, use the show controllers cable-modem lookup-table command in privileged EXEC mode. show controllers cable-modem number lookup-table Syntax Description number Controller number inside the Cisco uBR924. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.3 NA This command was first introduced.
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show controllers cable-modem lookup-table Examples The mini-slot lookup table is displayed in the following example: uBR924# show controllers cable-modem 0 lookup-table Max Burst Size (minislots) = 0x6 Max Burst Length (bytes) = 0x4B PHY Overhead Lookup Table: 000: 010: 020: 030: 040: 050: 060: 070: 080: 090: 0A0: 0B0: 0C0: 0D0: 0E0: 0F0: 100: 110: 120: 130: 140: 150: 160: 170: 180: 190: 1A0: 1B0: 1C0: 1D0: 1E0: 1F0: 200: 210: 220: 230: 240: 250: 260: 270: 280: 290: 2A0: 2B0: 2C0: 2D0: 2E0: 2F0: 300: 310:
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show controllers cable-modem lookup-table 370: 380: 390: 3A0: 3B0: 3C0: 3D0: 3E0: 3F0: 400: 410: 420: 430: 440: 450: 460: 470: 480: 490: 4A0: 4B0: 4C0: 4D0: 4E0: 4F0: 500: 510: 520: 530: 540: 550: 560: 570: 580: 590: 5A0: 5B0: 5C0: 5D0: 5E0: 5F0: 600: 610: 620: 630: 3C 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 68 68 68 68 68 68 68 68 68 68 68 68 68 68 77 77 77 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 4B 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 68 68 68 68 68 68 68 68
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show controllers cable-modem lookup-table 88: 90: 98: A0: A8: B0: B8: C0: C8: D0: D8: E0: E8: F0: F8: 07BC 07BC 0898 0898 0974 0974 0A50 0A50 0B2C 0C08 0C08 0CE4 0CE4 0DC0 0DC0 07BC 07BC 0898 0898 0974 0974 0A50 0B2C 0B2C 0C08 0C08 0CE4 0CE4 0DC0 0DC0 07BC 07BC 0898 0898 0974 0A50 0A50 0B2C 0B2C 0C08 0C08 0CE4 0CE4 0DC0 0DC0 07BC 07BC 0898 0974 0974 0A50 0A50 0B2C 0B2C 0C08 0C08 0CE4 0CE4 0DC0 0DC0 07BC 07BC 0898 0974 0974 0A50 0A50 0B2C 0B2C 0C08 0C08 0CE4 0CE4 0DC0 0E9C 07BC 0898 0898 0974 0974 0A5
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show controllers cable-modem mac show controllers cable-modem mac To display detailed MAC-layer information for a Cisco uBR924, use the show controllers cable-modem mac command in privileged EXEC mode. show controllers cable-modem number mac [errors | hardware | log | resets | state] Syntax Description number Controller number inside the Cisco uBR924. errors (Optional) Displays a log of the error events that are reported to SNMP.
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show controllers cable-modem mac Example 1 The following sample display shows the MAC log file for a cable-modem interface that has successfully registered with the CMTS: uBR924# show controllers cable-modem 0 mac log 00:14:24: 864.124 CMAC_LOG_DRIVER_INIT_IDB_RESET 0x080B7430 00:14:24: 864.128 CMAC_LOG_LINK_DOWN 00:14:24: 864.132 CMAC_LOG_RESET_FROM_DRIVER 00:14:24: 864.134 CMAC_LOG_STATE_CHANGE wait_for_link_up_state 00:14:24: 864.138 CMAC_LOG_LINK_UP 00:14:24: 864.
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show controllers cable-modem mac 00:14:32: 872.856 CMAC_LOG_RANGING_SUCCESS 00:14:32: 872.874 CMAC_LOG_STATE_CHANGE dhcp_state 00:14:33: 873.386 CMAC_LOG_DHCP_ASSIGNED_IP_ADDRESS 188.188.1.62 00:14:33: 873.388 CMAC_LOG_DHCP_TFTP_SERVER_ADDRESS 4.0.0.32 00:14:33: 873.392 CMAC_LOG_DHCP_TOD_SERVER_ADDRESS 4.0.0.32 00:14:33: 873.396 CMAC_LOG_DHCP_SET_GATEWAY_ADDRESS 00:14:33: 873.398 CMAC_LOG_DHCP_TZ_OFFSET 60 00:14:33: 873.402 CMAC_LOG_DHCP_CONFIG_FILE_NAME platinum.cm 00:14:33: 873.
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show controllers cable-modem mac Example 2 MAC error log information is displayed in the following example, which is also reported via SNMP: uBR924# show controllers cable-modem 0 mac errors 74373.574 R02.0 No Ranging Response received. T3 time-out. 74374.660 R02.0 No Ranging Response received. T3 time-out. 74375.508 R02.0 No Ranging Response received. T3 time-out. 74375.748 R02.0 No Ranging Response received. T3 time-out. 74375.748 R03.0 Ranging Request Retries exhausted. 74376.112 R02.
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show controllers cable-modem mac The following example indicates that an event in the cable interface driver caused the interface to reset. This often occurs because a shut or clear command is currently being issued on the interface. uBR924# show controllers cable-modem 0 mac resets 527986.444 CMAC_LOG_RESET_FROM_DRIVER 528302.042 CMAC_LOG_RESET_FROM_DRIVER 528346.600 CMAC_LOG_RESET_FROM_DRIVER 528444.
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show controllers cable-modem mac Table 6 Possible but Uncommon Cable Interface Reset Causes (continued) Message Description CMAC_LOG_RESET_SERVICE_NOT_AVAILABLE The CMTS has failed the Cisco uBR924’s registration because a required or requested class of service is not available. CMAC_LOG_RESET_T6_RETRIES_EXHAUSTED The CMTS failed too many times to respond to a REG-REQ message. CMAC_LOG_RESET_MAINTENANCE_WATCHDOG_DRIVER The Cisco uBR924 MAC layer failed to detect a change in the interface driver.
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show controllers cable-modem mac Example 4 The following example display for the show controllers cable-modem 0 mac hardware command shows the detailed configuration of the interface driver and the MAC-layer hardware. The most interesting bit is the station address (hardware address). The MIB statistics reflect the MAC hardware counters for various events, but these counters are typically reset every few seconds, so their contents are not accurate in this display.
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show controllers cable-modem mac TX BD ring with 8 entries at 0x201FB8, tx_count = 0 tx_head = 0x201FB8 (0), head_txp = 0x82D4888 (0) tx_tail = 0x201FB8 (0), tail_txp = 0x82D4888 (0) 00 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 01 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 02 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 03 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 04 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 05 pak=0x000000 buf=0x200000 status=0x00 pak_size=0 06 pak=0x000000
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show controllers cable-modem mac burst profiles: profile 0: 01 00 00 00 profile 1: 01 00 00 00 profile 2: 01 00 00 00 profile 3: 00 00 00 00 19 00 00 00 1D 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 19 00 00 00 1D 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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show controllers cable-modem mac Example 5 The show controllers cable-modem mac state command summarizes the state of the cable MAC layer and provides a list of downstream search frequency bands and the order in which they are searched. If the cable MAC layer is in the wait_for_link_up_state, the information shown in the display corresponds to the last time the interface was up. This allows useful information to be acquired from this display even though the modem has not been able to range and register.
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show controllers cable-modem mac Burst Descriptor 0: Interval Usage Code: Modulation Type: Differential Encoding: Preamble Length: Preamble Value Offset: FEC Error Correction: FEC Codeword Info Bytes: Scrambler Seed: Maximum Burst Size: Guard Time Size: Last Codeword Length: Scrambler on/off: Burst Descriptor 1: Interval Usage Code: Modulation Type: Differential Encoding: Preamble Length: Preamble Value Offset: FEC Error Correction: FEC Codeword Info Bytes: Scrambler Seed: Maximum Burst Size: Guard Time Si
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show controllers cable-modem mac COS 1: Assigned SID: Max Downstream Rate: Max Upstream Rate: Upstream Priority: Min Upstream Rate: Max Upstream Burst: Privacy Enable: Ranging Backoff Start: Ranging Backoff End: Data Backoff Start: Data Backoff End: IP Address: Net Mask: 5 4000000 2000000 7 100000 12 TRUE 0 (at initial 4 (at initial 0 (at initial 4 (at initial 0.0.0.0 0.0.0.0 TFTP Server IP Address: Time Server IP Address: Config File Name: Time Zone Offset: 223.255.254.254 188.188.1.
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show controllers cable-modem mac Table 8 Show Controllers Cable-Modem MAC State Field Descriptions (continued) Field Description DS Symbol Rate Downstream frequency in symbols per second. DS QAM Mode Downstream modulation scheme being used by the Cisco uBR924. DS Search Frequency bands scanned by the Cisco uBR924 when searching for a downstream channel.
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show controllers cable-modem mac Table 8 Show Controllers Cable-Modem MAC State Field Descriptions (continued) Field Description Maximum Burst Size Maximum number of mini-slots that can be transmitted during this burst type. When the interval type is Short Data Grant, this value must be greater than 0. If this value is 0, the burst size is limited elsewhere.
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show controllers cable-modem mac Table 8 Show Controllers Cable-Modem MAC State Field Descriptions (continued) Field Description Ranging Backoff End Final back-off window for initial ranging contention, expressed as a power of 2. Valid values are from 0 to 15. Data Backoff Start Initial back-off window for contention data and requests, expressed as a power of 2. Valid values are from 0 to 15. Data Backoff End Final back-off window for contention data and requests, expressed as a power of 2.
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show controllers cable-modem phy show controllers cable-modem phy To display the contents of the registers used in the downstream physical hardware of the Cisco uBR924 cable access router, use the show controllers cable-modem phy command in privileged EXEC mode. show controllers cable-modem phy {receive | transmit} Syntax Description receive Displays all receiver registers in the downstream physical hardware. transmit Displays all transmitter registers in the upstream physical hardware.
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show controllers cable-modem phy ldsft=B0EE ldbbq=00000000 ldbri=F9CDC200 ldsnre=0098AF ldali=032E00 lddrfo=007E7D ldif=0D004E ldaii=E62AF2 lddri=007EF0 ldbbi=00000000 ldbrfo=705A05 FEC correctable error count: 0 FEC uncorrectable error count: 0 Bit Error Rate Count: 0 Physical transmit registers are displayed in the following example: uBR924# show controllers cable-modem BCM3037 Transmitter Registers: part_id = 3037 rev_id test_mode = 00 test_input test_misc = 2009 rst power = 0000 power_2 port = 6F
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show controllers cable-modem phy Related Commands Command Description show controllers cable-modem Displays high-level controller information about a Cisco uBR924 cable access router. show controllers cable-modem bpkm Displays information about the baseline privacy key management exchange between the Cisco uBR924 and the CMTS. show controllers cable-modem des Displays information about the Data Encryption Standard (DES) engine registers. show controllers cable-modem filters .
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show controllers cable-modem tuner show controllers cable-modem tuner To display the settings for the upstream and downstream tuners used by a Cisco uBR924 cable access router, use the show controllers cable-modem tuner command in privileged EXEC mode. show controllers cable-modem tuner Syntax Description There are no key words or arguments for this command. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.
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show controllers cable-modem tuner Table 9 Show Controllers Cable-Modem Tuner Field Descriptions Field Description tuner_freq Indicates the current downstream frequency. symbol_rate Indicates the downstream symbol rate in symbols per second. local_freq Frequency on which the transmitter and tuner communicate. snr_estimate Signal to noise estimate in dB X 1000. ber_estimate Bit error rate estimate (always 0).
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show controllers cable-modem tuner Debug Commands The following debug commands are available to troubleshoot a Cisco uBR924 cable access router: • • • • • • debug cable-modem bpkm debug cable-modem bridge debug cable-modem error debug cable-modem interrupts debug cable-modem mac debug cable-modem map Note Troubleshooting the Cisco uBR924 cable access router is typically accomplished using the CMTS at the cable operator’s headend facility; it is rarely done by directly accessing the Cisco uBR924.
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debug cable-modem bpkm debug cable-modem bpkm To debug baseline privacy information on a Cisco uBR924, use the debug cable-modem bpkm command in privileged EXEC mode. To turn the debugging messages off, use the no form of this command. [no] debug cable-modem bpkm {errors | events | packets} Syntax Description errors Debugs Cisco uBR924 privacy errors. events Debugs events related to cable baseline privacy. packets Debugs baseline privacy packets. Defaults No default behavior or values.
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debug cable-modem bpkm Related Commands 60 Command Description debug cable-modem bridge Debugs bridge filter processing information on a Cisco uBR924. debug cable-modem error Enables debugging messages for the cable interface driver on a Cisco uBR924. debug cable-modem interrupts Debugs Cisco uBR924 interrupts. debug cable-modem mac Troubleshoots the Cisco uBR924 MAC layer. debug cable-modem map Displays the timing from MAP messages to sync messages and the timing between MAP messages.
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debug cable-modem bridge debug cable-modem bridge Use the debug cable-modem bridge command in privileged EXEC mode to debug bridge filter processing information on a Cisco uBR924. To turn the debugging messages off, use the no form of this command. [no] debug cable-modem bridge Syntax Description This command has no keywords or arguments. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.3 NA This command was first introduced.
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debug cable-modem bridge Related Commands 62 Command Description debug cable-modem bpkm Debugs baseline privacy information on a Cisco uBR924. debug cable-modem error Enables debugging messages for the cable interface driver on a Cisco uBR924. debug cable-modem interrupts Debugs Cisco uBR924 interrupts. debug cable-modem mac Troubleshoots the Cisco uBR924 MAC layer. debug cable-modem map Displays the timing from MAP messages to sync messages and the timing between MAP messages.
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debug cable-modem error debug cable-modem error Use the the debug cable-modem error command in privileged EXEC mode to enable debugging messages for the cable interface driver. To turn the debugging messages off, use the no form of this command. [no] debug cable-modem error Syntax Description This command has no keywords or arguments. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.3 NA This command was first introduced.
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debug cable-modem error Related Commands 64 Command Description debug cable-modem bpkm Debugs baseline privacy information on a Cisco uBR924. debug cable-modem bridge Debugs bridge filter processing information on a Cisco uBR924. debug cable-modem interrupts Debugs Cisco uBR924 interrupts. debug cable-modem mac Troubleshoots the Cisco uBR924 MAC layer. debug cable-modem map Displays the timing from MAP messages to sync messages and the timing between MAP messages. Cisco IOS Release 12.
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debug cable-modem interrupts debug cable-modem interrupts To debug Cisco uBR924 interrupts, use the debug cable-modem interrupts command in privileged EXEC mode . To turn the debugging messages off, use the no form of this command. [no] debug cable-modem interrupts Syntax Description This command has no keywords or arguments. Defaults No default behavior or values. Command Modes Privileged EXEC Command History Release Modification 11.3 NA This command was first introduced.
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debug cable-modem interrupts Related Commands 66 Command Description debug cable-modem bpkm Debugs baseline privacy information on a Cisco uBR924. debug cable-modem bridge Debugs bridge filter processing information on a Cisco uBR924. debug cable-modem error Enables debugging messages for the cable interface driver on a Cisco uBR924. debug cable-modem mac Troubleshoots the Cisco uBR924 MAC layer.
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debug cable-modem mac debug cable-modem mac To troubleshoot the Cisco uBR924 MAC layer, use the debug cable-modem mac command in privileged EXEC mode. To turn the debugging messages off, use the no form of this command. [no] debug cable-modem mac {log [verbose] | messages} Syntax Description log Realtime MAC log display. verbose (Optional) Displays periodic MAC layer events, such as ranging. messages MAC layer management messages. Defaults No default behavior or values.
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debug cable-modem mac Examples Example 1 This example shows sample display output from the debug cable-modem mac log command. The fields of the output are the time since bootup, the log message, and in some cases a parameter that gives more detail about the log entry. uBR924# debug cable-modem mac log *Mar 7 01:42:59: 528302.040 CMAC_LOG_LINK_DOWN *Mar 7 01:42:59: 528302.042 CMAC_LOG_RESET_FROM_DRIVER *Mar 7 01:42:59: 528302.044 CMAC_LOG_STATE_CHANGE wait_for_link_up_state *Mar 7 01:42:59: 528302.
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debug cable-modem mac 0 events dropped due to lack of a chunk The line “0 events dropped due to lack of a chunk” at the end of a display indicates that no log entries were discarded due to a temporary lack of memory. This means the log is accurate and reliable. Example 2 The following example compares the output of the debug cable-modem mac log command with the debug cable-modem mac log verbose command. The verbose keyword displays periodic events such as ranging.
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debug cable-modem mac In addition, transmitted REG-REQs are displayed in hex dump format. The output from this command is very verbose and is usually not needed for normal interface debugging. The command is most useful when attempting to attach a Cisco uBR924 cable access router to a CMTS that is not DOCSIS-qualified. For a description of the displayed fields of each message, refer to the DOCSIS Radio Frequency Interface Specification, v1.0 (SP-RFI-I04-980724).
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debug cable-modem mac *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar . . *Mar *Mar *Mar *Mar *Mar *Mar *Mar *Mar . .
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debug cable-modem mac *Mar *Mar 7 01:44:20: 7 01:44:20: MAC MANAGEMENT MESSAGE HEADER DA - 00F0.1EB2.BB61 Related Commands 72 Command Description debug cable-modem bpkm Debugs baseline privacy information on a Cisco uBR924. debug cable-modem bridge Debugs bridge filter processing information on a Cisco uBR924. debug cable-modem error Enables debugging messages for the cable interface driver on a Cisco uBR924. debug cable-modem interrupts Debugs Cisco uBR924 interrupts.
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debug cable-modem map debug cable-modem map To display the timing from MAP messages to sync messages and the timing between MAP messages on a Cisco uBR924 cable access router, use the debug cable-modem map command in privileged EXEC mode. To turn the debugging messages off, use the no form of this command. [no] debug cable-modem map Syntax Description This command has no keywords or arguments. Defaults No default behavior or values.
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debug cable-modem map Related Commands 74 Command Description debug cable-modem bpkm Debugs baseline privacy information on a Cisco uBR924. debug cable-modem bridge Debugs bridge filter processing information on a Cisco uBR924. debug cable-modem error Enables debugging messages for the cable interface driver on a Cisco uBR924. debug cable-modem interrupts Debugs Cisco uBR924 interrupts. debug cable-modem mac Troubleshoots the Cisco uBR924 MAC layer. Cisco IOS Release 12.