Basic Troubleshooting
Configuring the Cisco uBR900 Series Cable Access Routers 27
The downstream frequency search table is arranged so that the first frequencies that are scanned 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.
The
CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND field tells you what frequencies the cable access
router will scan. The CMAC_LOG_WILL_SEARCH_SAVED_DS_FREQUENCY field tells you the frequency
the router locked onto and saved to NVRAM for future recall. The
CMAC_LOG_DS_64QAM_LOCK_ACQUIRED field communicates the same information. The
CMAC_LOG_DS_CHANNEL_SCAN_COMPLETED field indicates that the scanning and synchronization was
successful.
508144.348 CMAC_LOG_STATE_CHANGE ds_channel_scanning_state
508144.350 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 88/453000000/855000000/6000000
508144.354 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 89/93000000/105000000/6000000
508144.356 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 90/111250000/117250000/6000000
508144.360 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 91/231012500/327012500/6000000
508144.362 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 92/333015000/333015000/6000000
508144.366 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 93/339012500/399012500/6000000
508144.370 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 94/405000000/447000000/6000000
508144.372 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 95/123015000/129015000/6000000
508144.376 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 96/135012500/135012500/6000000
508144.380 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 97/141000000/171000000/6000000
508144.382 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 98/219000000/225000000/6000000
508144.386 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND 99/177000000/213000000/6000000
508144.390 CMAC_LOG_WILL_SEARCH_SAVED_DS_FREQUENCY 699000000
508145.540 CMAC_LOG_UCD_MSG_RCVD 3
508146.120 CMAC_LOG_DS_64QAM_LOCK_ACQUIRED 699000000
508146.122 CMAC_LOG_DS_CHANNEL_SCAN_COMPLETED
Event 3—Obtain Upstream Parameters
The Cisco uBR900 series waits for an upstream channel descriptor (UCD) message from the CMTS.
The UCD provides transmission parameters for the upstream channel.
508146.124 CMAC_LOG_STATE_CHANGE wait_ucd_state
508147.554 CMAC_LOG_UCD_MSG_RCVD 3
508147.558 CMAC_LOG_UCD_NEW_US_FREQUENCY 20000000
508147.558 CMAC_LOG_SLOT_SIZE_CHANGED 8
508147.622 CMAC_LOG_FOUND_US_CHANNEL 1
508147.624 CMAC_LOG_STATE_CHANGE wait_map_state
508148.058 CMAC_LOG_MAP_MSG_RCVD
508148.060 CMAC_LOG_INITIAL_RANGING_MINISLOTS 40
Event 4—Start Ranging for Power Adjustments
The ranging process adjusts the transmit power of the cable access router. Ranging is performed in
two stages: ranging state 1 and ranging state 2.
The CMAC_LOG_POWER_LEVEL_IS field is the power level that the CMTS told the CiscouBR900
series to adjust to. The
CMAC_LOG_RANGING_SUCCESS field indicates that the ranging adjustment was
successful.
508148.062 CMAC_LOG_STATE_CHANGE ranging_1_state
508148.064 CMAC_LOG_RANGING_OFFSET_SET_TO 9610
508148.066 CMAC_LOG_POWER_LEVEL_IS 28.0 dBmV (commanded)
508148.068 CMAC_LOG_STARTING_RANGING
508148.070 CMAC_LOG_RANGING_BACKOFF_SET 0
508148.072 CMAC_LOG_RNG_REQ_QUEUED 0
508148.562 CMAC_LOG_RNG_REQ_TRANSMITTED
508148.566 CMAC_LOG_RNG_RSP_MSG_RCVD