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28-4
Catalyst 2950 Desktop Switch Software Configuration Guide
78-14982-01
Chapter28 Troubleshooting
LRE Statistics
Table 28-2 LRE Link Statistics
Statistic Type Explanation
Upstream Bandwidth Usage The percentage of the bandwidth used for upstream traffic, based on the current upstream rate
and actual upstream speed of LRE link.
Downstream Bandwidth
Usage
The percentage of the bandwidth used for downstream traffic, based on the current
downstream rate and actual downstream speed of the LRE link.
Signal to Noise Ratio The amount of increased received signal noise (in decibels) relative to the ambient,
environment, and electromagnetic noise power level that the switch is designed to tolerate
without disconnecting from the remote LRE CPE device. The higher the ratio, the more
resilient the link.
Upstream Reed-Solomon
Errors
The number of detected and corrected data errors being received on the switch LRE port.
Reed-Solomon errors result from noise exceeding the noise margin. For short bursts of noise
(such as motor startup or power surges), the Reed-Solomon error correction prevents the loss
of Ethernet data frames.
The LRE interface corrects the data bytes that are incorrectly received on the switch LRE port
(up to a designed 8-byte limit). The residual error rate is better than the detection capability
of the Ethernet cyclic redundancy check (CRC). If the error burst is larger than the correction
capability of the LRE interface, the Ethernet CRC is used to determine the corrupted frames
and to discard them.
Downstream Reed-Solomon
Errors
The number of detected and corrected data errors being received on the CPE RJ-11 wall port.
Table 28-3 CPE Ethernet Link Statistics
Counter Description
Transmit
Bytes Total number of bytes transmitted out of this port.
Unicast Frames The total number of well-formed unicast frames sent by a port. It excludes frames sent with
errors or with multicast or broadcast destination addresses.
Multicast Frames The total number of well-formed multicast frames sent by a port. It excludes frames sent with
errors or with unicast or broadcast destination addresses.
Broadcast Frames The total number of well-formed broadcast frames sent by a port. It excludes frames sent with
errors or with unicast or multicast destination addresses.
Dropped Frames The count of frames that were dropped before transmission.
Pause Frames Incremented for each MAC pause control frame transmitted.
Collision Frames The total number of frames sent without error after having 1 to 15 collisions. It includes
frames of all destination address types and excludes frames discarded because of insufficient
resources or late collisions.
One Collision Frames Incremented for each frame that experienced exactly one collision during its transmission
attempt.
Multiple Collisions Incremented for each frame that experienced more than one collision during its transmission
attempt.