USRobotics V.34 - Manual (Page 78)

COURIER HIGH SPEED MODEMS
Queries and Help Screens 6-5
GSTN (General Switch Telephone Network) Clear Down:
The connection was non-ARQ and DTR was dropped from
one side of the connection, or the DISC frame was corrupted
due to noise.
Illegal Command Code: The modem received an invalid V.42
bis (compression) frame.
Inactivity timeout: The modem detected no activity on the
line for the duration specified in Register S19 (default is 0,
timer disabled).
Invalid Codeword: The modem received an invalid V.42 bis
(compression) frame.
Invalid speed: The modem is set to &N1 or higher, for a
fixed link rate, and the remote modem is not operating at the
same rate.
LD received: The remote modem sent an MNP error control
Link Disconnect request.
Loop loss disconnect: The modem detected a loss of current
on the loop connecting it with the telephone company central
office. This usually occurs because the remote modem has
hung up: the central office drops current momentarily when
there is a disconnect at the other end of a call. Unless
Register S38 is set higher than zero, the modem immediately
hangs up at loop loss.
Loss of carrier: The modem detected loss of the remote
modem's carrier and waited the duration specified in
Register S10 (default is 0.7 seconds).
MNP incompatibility: The modem is set to &M5 and the
remote modem does not have MNP capability, or there was
an MNP negotiation procedure error.
Retransmit limit: The modems reached the maximum of
twelve attempts to transfer a data frame without error.
SABME Timeout (Set Asynchronous Balance Mode
Extended): The modems failed this part of V.42 link
negotiation.