How does one shut off MNP checking on 2224 CEO AT&T modem?

[Bill Mayhew]

I was recently given an AT&T 2224 CEO modem to test out.  Basically
a very nice box.  It works great talking to other MNP modems.  What
I need to know the appropriate "AT&" command to shut off MNP so
that I can talk to a 3b1 with it.  I was able to figure most of the
other AT and AT& commands out by inferring operation from other
2400 baud modems, but this one setting has eluded me.

Thanks for any tips.

--Bill