Link Status Report (Ati2) - ZyXEL Communications U-336R/RE User Manual

FRN (Fast Rate Negotiation) Granted (FG)
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 (FR)
The count of the local modem's requests to change the rate.
Block Retransmitted (BR)
The count of the blocks retransmitted (bad reception on the remote
modem).
FCS (Frame Check Sum) Errors (FE)
The count of the FCS errors received (block errors) (bad reception
on the local modem).

Link Status Report (ATI2)

During a connection, the modem will record information about link
operations. You can use the AT command ATI2 to see the
summary, as show in the sample below:
122 Diagnostics & Troubleshooting
ZyXEL U-MODEM LINK STATUS REPORT
ZyXEL U-MODEM LINK STATUS REPORT
Chars Sent
Chars Received
Octets Sent
Octets Received
Blocks Sent
Blocks Received
Blocks Resent
Max Outstanding
Max Block Size
2420
2420
950
950
13
13
0
8
256