EXFO FTB-635 Wideband Copper and DSL Test Module - Manual (Page 333)

xDSL Test Results
Copper and xDSL Tests 325
DSL Statistics

DSL Counters lists the Local and Remote results for the following
counters:

CRC is the cyclical redundancy check Interleaved/Fast counter.

FEC is the Reed Solomon forward error correction.

Error Seconds is the number of seconds when code violation is
detected.

HEC is the header error check (HEC) Interleaved/Fast counter.
Available only in ATM connection mode.

Parameter - Received/Transmitted

DSL Bytes records the number of active (non-idle) PTM/ATM cells
or frames on a channel.

Packets displays the number of packets.

Performance Counters - Local/Remote

G.INP RTX_TX is the number of frames retransmitted by the
transmitter. The Local number is what is retransmitted from the
CPE to the DSLAM. The Remote value is what is retransmitted from
the DSLAM to the CPE.
Note: The RTX_TX number may contain retransmits not requested by the receiver
(that is, the retransmission request channel got corrupted and a
retransmission was sent automatically) resulting in an incremental value
even though the same frame ID was retransmitted multiple times.

G.INP RTX_C is a counter that is increased each time a frame is
detected in error and has successfully been corrected by a
retransmission. The Local number is received by the CPE, the
Remote value received by the DSLAM.