Sierra Wireless DART 200 CDPD Modem - Manual (Page 46)

DART 200 CDPD Modem User’s Guide 2 Installation and Setup
Sierra Wireless, Inc. 2-22
If increasing the time-out period does not correct the time-out failures,
the problem could be that the other device is not registered, or that the
path to it is not operational. Check with those responsible for the other
device to see that it is operational and registered. Next, check S-Register
57 to see if you have a channel and are still registered. If you are, then
verify that the IP Address of the ping target is correct. If S-Register 57
status is fine and the IP Address is also fine, contact your carrier to check
for network connectivity between the local modem and remote device.