Netopia 435 Reference Manual page 197

10-4 Netopia ISDN Router Reference Guide
Loopback Test PASSED. The loopback test was successful. The
line is working properly, and the directory numbers (the ISDN phone
numbers associated with each B-channel) are correct. If a SPID is
associated with the first B-channel, its correctness is also
confirmed. If a SPID is associated with the second B-channel, its
correctness is confirmed.
Note: SPIDs are applicable to certain North American ISDN switch
protocols.
If the loopback test fails
Follow these suggestions to track down the reason behind the
loopback test's failure:
Check that the SYNC LED is glowing a solid green.
Check the ISDN event log and get more information about
events that seem relevant to the failure.
Checking the B-channel usage in the Quick View screen to
make sure there were no incoming calls when the loopback test
was performed.
Check the accuracy of the directory numbers, SPIDS, and
switch protocol you entered in the ISDN Line Configuration
screen (compare them with the information you received from
your telephone company).
Switch on termination of the S/T bus.
Contact your telephone company to have the line checked.