> its V42 listing as "Error Control: V42 (LAP-M)"  The
 > inference I draw is
 > that if MNP fallback occurs then the V42bis compression
 > becomes non- operational

By all means draw that inference, but it may be more correct to interpret
it as most people think V.42 *is* an error control protocol, as opposed to
it being a protocol which negotiates such things. "LAPM" doesn't
sound at all ITU-ish, because people *know* ITU protocols as being Vee-dot
references. Moreover, you may add to that that if MNP fallback occurs, then
the modem follows the only route it knows to MNP compatible data
compression, that being selection of MNP5. Couriers don't know about
Microcom's route to MNP with V.42bis.

Edward

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