Cisco WS-C2960S-48TD-L Software Guide - Page 271

Chapter 9 Troubleshooting Statistics Table 9-3 LRE Link Statistics Statistic Type Upstream Bandwidth Usage Downstream Bandwidth Usage Signal to Noise Ratio Upstream Reed-Solomon Errors Downstream Reed-Solomon Errors Explanation The percentage of the bandwidth used for upstream traffic, based on the current upstream rate and actual upstream speed of LRE link. The percentage of the bandwidth used for downstream traffic, based on the current downstream rate and actual downstream speed of the LRE link. 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. The higher the ratio, the more resilient the link. 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 packets. 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 packets and to discard them. The number of detected and corrected data errors being received on the CPE RJ-11 wall port. Table 9-4 CPE Ethernet Link Statistics Counter Tx Octets Tx Drop Pkts Tx Broadcast Pkts Tx Multicast Pkts Tx Unicast Pkts Tx Collisions Tx Multiple Collisions Deferred transmits Late collisions Excessive collisions In frame discards Tx Pause Pkts Carrier sense errors Rx Octets Rx Undersize Pkts Description The count of octets sent from an LRE CPE Ethernet port. The count of packets dropped during transmission out an LRE CPE Ethernet port. The count of packets with a broadcast destination sent from LRE CPE Ethernet port. The count of packets with a multicast destination sent from an LRE CPE Ethernet port. The count of packets with a unicast destination sent from an LRE CPE Ethernet port. The count of packets that could not be sent due to a single collision on the medium. The count of packets that could not be sent due to multiple collisions on the medium. The count of packets that could not be sent because the medium was busy The count of packets that were not sent because a collision happened after 512 bit times into the transmission of the packet. The count of packets that could not be sent due to excessive collisions. The number of valid packets received that were discarded due to lack of space on an output queue. The count of 802.3X pause frames sent out by the LRE CPE Ethernet port. The number of times that the carrier sense condition was lost or never asserted when attempting to send a frame on the Ethernet interface of a CPE. The count of octets received by the LRE CPE Ethernet port. The count of packets received by the LRE CPE Ethernet port, with size lesser than 64 bytes. 78-6511-08 Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide 9-5