LAPM or MNP or None, depending on V.42 negotiation 7. V42bis or MNP or None, depending on V.42 negotiation 8. Mean-square error of received downstream signal. Difference between received constellation point and reference decision point. This is a dimensionless decimal number, only valid during a call.
Higher numbers are worse.
The number varies during a call, so it can be useful to sample it a few times. The value reported in this field is only valid while on-line, and even then is not very meaningful for troubleshooting. Only valid during a call. Note - incorrect values are reported for V.90 and K56Flex connections. Upstream transmit signal power.