3Com 56K manual Selective data compression. The modem, Negotiates only for V.42bis compression

B-8APPENDIX B: ALPHABETIC COMMAND SUMMARY

Command	Function
	&K3	Selective data compression. The modem
		negotiates only for V.42bis compression, and
		disables MNP Level 5 (MNP5) compression. Use
		this setting to transfer compressed files.
&Ln	Line type.
	&L0	Normal.
&Mn	Enable ARQ (error control) protocol. Both your modem and the
	remote device must use the same protocol.
	&M0	Normal mode, no error control. Due to the nature
		of phone line channels, this is never
		recommended for calls above 2400 bps.
	&M4	Normal/ARQ mode. If an ARQ connection isn't
		made, the modem operates in Normal mode as
		though it were set to &M0.
&Nn	Sets fixed link speed.
&Nn&UN	Sets highest and lowest link speeds
	n=1	Variable rate. The modem negotiates with the
		remote device for the highest possible connection
		rate, depending on the capabilities of the remote
		device.
	n = 1 -16	Fixed rate. The modem connects only if the
		remote device is operating at the same rate. You
		can use this feature to filter out calls at other than
		a specific rate for security or other reasons.
		The connection rate must always be lower than or
		equal to the serial port rate.
		n=1	300 bps
		n=2	1200 bps
		n=3	2400 bps
		n=4	4800 bps
		n=5	7200 bps
		n=6	9600 bps
		n=7	12000 bps
		n=8	14400 bps
		n=9	16800 bps
		n=10	19200 bps
		n=11	21600 bps
		n=12	24000 bps