show controllers cable-modem
Troubleshooting Tips for the Cisco uBR924 Cable Access Router 23
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.
local_freq Frequency on which the transmitter and the tuner communicate.
snr_estimate Estimate of signal-to-noise ratio (SNR) in Db X 1000.
ber_estimate Estimate of bit error rate (always 0).
lock_threshold Minimum signal-to-noise ratio (SNR) that the Cisco uBR924 will accept as a valid lock.
qam_mode The modulation scheme used in the downstream direction.
Tx: tx_freq Upstream frequency sent to the Cisco uBR924 by the CMTS in the UCD message.
power_level Transmit power level as set in the hardware, expressed as a hexadecimal value. The
units are unique to the hardware used. Use the show controllers cable-modem 0 mac
state command to see the power level in dBmV.
symbol_rate Upstream frequency in symbols per second.
TFTP server IP address of the TFTP server at the headend.
TOD server IP address of the time-of-day server at the headend.
Security server IP address of the security server at the headend.
Timezone Offset Correction received from the DHCP server to synchronize the Cisco uBR924 time clock
with the CMTS.
Config filename Name of the file stored on the cable company’s TFTP server that contains operational
parameters for the Cisco uBR924.
buffer size Size in bytes of the BCM3300 message buffers.
RX data PDU ring:
rx_head
rx_p
Indicates the memory location of the beginning of buffer information for the receive
data ring.
Indicates current head buffer descriptor.
Indicates current head packet descriptor.
RX MAC message ring:
rx_head_mac
rx_p_mac
Indicates the memory location of the beginning of buffer information for the receive
MAC message ring.
Indicates current head buffer descriptor.
Indicates current head packet descriptor.
TX BD ring:
tx_count
tx_head
head_txp
tx_tail
tail_txp
Indicates the memory location of the beginning of buffer information for the transmit
buffer descriptor ring.
If tx_count is 0, or if tx_head and tx_tail are equal and there is no change for a period of
time, it means there are packets stuck on the ring. This condition may be caused by the
headend not giving grants.
The next packet descriptor to get used, along with its index.
The next packet descriptor to get sent, along with its index. When head_txp and tail_txp
are the same, the transmit queue is empty.
Table2 Show Controllers Ca bl e-Modem Field Descriptions (continued)
Field Description