ZyXEL Communications U-336S User Manual page 148

Retrain Granted (RTG)
The count of the granting of the remote modem's retrain requests. Each
request is an indicator of bad receiving conditions.
Retrain Requested (RTR)
The count of the local modem's requests for the remote modem to
retrain when the signal quality is poor.
Round Trip Echo Delay (RTD)
Measured in T (1/2400 sec.). Will be re-measured in every retrain
action.
Carrier Loss Counter (CLC)
When operated over a leased line, it is the count of the carrier's
temporary drop-out, if there is any.
ON-LINE SCREEN 4 also has four counters recording the modem's
actions and reactions.
FRN (Fast Rate Negotiation) Granted (FRG)
The count of the granting of the remote modem's change rate (FRN)
requests. Each request is an indicator of a changed receiving condition.
FRN Request (FRR)
The count of the local modem's requests to change the rate.
Block Retransmitted (BLR)
The count of the blocks retransmitted (bad reception on the remote
modem).
FCS (Frame Check Sum) Errors (FRE)
The count of the FCS errors received (block errors) (bad reception on
the local modem).
134 Diagnostics & Troubleshooting