Cisco Broadband Cable Command Reference Guide

Chapter 5 Cable CPE Commands
OL-1581-05
Table 5-4 show controllers cable-modem Field Descriptions
show controllers cable-modem
Field Description
TX BD ring: Indicates the memory location of the beginning of buffer information for the
transmit buffer descriptor ring.
tx_count 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 CMTS not giving grants.
tx_head Indicates current head transmit packet descriptor.
head_txp The next packet descriptor to get used, along with its index.When head_txp
and tail_txp are the same, the transmit queue is empty.
tx_tail Indicates current tail transmit packet descriptor.
tail_txp 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.
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.
MIB Statistics
DS fifo full Number of times the downstream input first-in first-out (FIFO) buffer
became full on the router.
rerequests Number of times a bandwidth request generated by the router was not
responded to by the CMTS.
DS mac msg overruns Number of times the router’s DMA controller had a downstream MAC
message and there were no free MAC message buffer descriptors to accept
the message.
DS data overruns Number of times the router’s DMA controller had downstream data and there
were no free data PDU buffer descriptors to accept the data.
Qualified maps Number of times a MAP message passed all filtering requirements and was
received by the router.
Qualified syncs Number of times a timestamp message was received by the router.
CRC fails Number of times a MAC message failed a cyclic redundancy check (CRC).
HDR chk fails Number of times a MAC header failed its 16-bit CRC check. The MAC
header CRC is a 16-bit Header Check Sequence (HCS) field that ensures the
integrity of the MAC header even in a collision environment.
Data pdus Total number of data protocol data units (PDUs) of all types received by the
router.
Mac msgs Number of MAC messages received by the router.
Valid hdrs Number of valid headers received by the router, including PDU headers,
MAC headers, and headers only.
Global control and Used to reset the BCM3300 chip.
status:
interrupts: Hexadecimal values of the pending IRQ interrupt and IRQ mask.
Cisco Broadband Cable Command Reference Guide
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