Here is the default initchat setting:
all.initchat    TIMEOUT 10 \
		ABORT "NO CARRIER" \
		ABORT VOICE \
                "" \d\l\dATZ \
                OK\r\n-ATZ-OK\r\n "\c" \
                TIMEOUT 3600 \
                RING "\c" \
                STATUS Incoming %p:I.HANDSHAKE \
                "" ATA \
                TIMEOUT 75 \
                CONNECT@ "\c" \
                STATUS Connected %p:I.HANDSHAKE

Here's a chat script that matches Nicholas's suggestion and may work better
with USR Courier V.everything modems.  Please note that as this is an
undocumented and non-standard AT command I provide no guarantee about the
following, it may potentially cause hardware damage if used in the wrong way...

all.initchat    TIMEOUT 10 \
		ABORT "NO CARRIER" \
		ABORT VOICE \
                "" \d\l\dATNX \
		"" \d\d\l\dATZ \
                OK\r\n-ATZ-OK\r\n "\c" \
                TIMEOUT 3600 \
                RING "\c" \
                STATUS Incoming %p:I.HANDSHAKE \
                "" ATA \
                TIMEOUT 75 \
                CONNECT@ "\c" \
                STATUS Connected %p:I.HANDSHAKE


From: "Nicholas Tretyachenko" <tkola@amfitel.ru>
 To: "Bill Roberts" <williamr@powwwer.net>, <portslave@linuxrouter.org>

 Hello all
We have also been suffering from USR V.everything lockups, but have
decreased possibility of modem lockup with undocumented ATNX command on
every initialization of modem. This command resets RAM of the modem's DSP.
Probably cause of lockups is overheating of DSP's RAM.


Try to initialize your modems that way:

ATNX (then wait for a couple seconds (\d\d). Modem doesn't respond with OK)
ATZ (or your preferred initialization string)


With regards,
Nicholas Tretyachenko
