Troubleshooting guide

7-24
Cisco Broadband Local Integrated Services Solution Troubleshooting Guide
OL-5169-01
Chapter 7 Troubleshooting the CMTS
Troubleshooting the Cisco uBR7246VXR
Registration - reject (c) state
A cable modem that fails registration due to bad class of service (COS) has a state of reject(c). Typically
this is caused by:
• uBR is unable or unwilling to grant a particular requested COS
• Misconfigured parameter(s) in Class of Service option in DOCSIS CPE Configurator, such as
having two classes of service with the same ID
Following is output from debug cable-modem mac log verbose taken on the cable modem side showing
failure due to bad COS:
1w3d: 885643.820 CMAC_LOG_STATE_CHANGE registration_state
1w3d: 885643.820 CMAC_LOG_REG_REQ_MSG_QUEUED
1w3d: 885643.824 CMAC_LOG_REG_REQ_TRANSMITTED
1w3d: 885643.828 CMAC_LOG_REG_RSP_MSG_RCVD
1w3d: 885643.828 CMAC_LOG_SERVICE_NOT_AVAILABLE 0x01,0x01,0x01
1w3d: 885643.828 CMAC_LOG_RESET_SERVICE_NOT_AVAILABLE
1w3d: 885643.828 CMAC_LOG_STATE_CHANGE reset_interface_state
1w3d: 885643.832 CMAC_LOG_STATE_CHANGE reset_hardware_state
1w3d: 885644.416 CMAC_LOG_STATE_CHANGE wait_for_link_up_state
1w3d: 885644.420 CMAC_LOG_DRIVER_INIT_IDB_RESET 0x8039E23C
1w3d: 885644.420 CMAC_LOG_LINK_DOWN
1w3d: 885644.420 CMAC_LOG_LINK_UP
1w3d: 885644.420 CMAC_LOG_STATE_CHANGE ds_channel_scanning_state
133.CABLEMODEM.CISCO: 1w3d: %LINEPROTO-5-UPDOWN: Line protocol on Interface cable-modem0,
changed state to down
1w3d: 885645.528 CMAC_LOG_UCD_MSG_RCVD 1
1w3d: 885646.828 CMAC_LOG_DS_64QAM_LOCK_ACQUIRED 453000000
Similarly, debug cable registration on the Cisco uBR7246VXR gives the following output:
sniper#debug cable registration
CMTS registration debugging is on
sniper#
1d04h: %UBR7200-5-CLASSFAIL: Registration failed for Cable Modem 0001.9659.4461 on
interface Cable2/0/U0:
Bad/Missing Class of Service Config in REG-REQ
Note how the cable modem eventually resets and starts all over again.