Telos Zephyr Xstream - Manual (Page 300)

USER’S MANUAL
Section 13: Deep Tech Information and Troubleshooting 288
When using the built‐in NT1, and the U sync LED occasionally cycles to the fast
flashing state, then the line or NT1 is marginal.
What is consistent about the problem (look for patterns)?
Keep watching for a pattern. Enlist the help of the users. We’ve seen apparently
random problems that we eventually discovered only occurred when it rained, or on
a certain day each week, or at a certain time of day, or only when another line was
in use. In other cases, difficulties were due to temperature or dirty AC power.
Assume nothing, and suspect everything. Leave no stone unturned while searching
for the answer.
Any other ISDN troubleshooting Tips?
An important tool for understanding fundamental compatibility problems is the Zephyr
Xstream’s integrated ISDN analyzer. This allows examination of the transactions between the
Telco line and the Xstream, so that a judgment can be made as to whether the problem lies
within the Xstream or with the programming of the Telco switch. This can be useful when the
line itself tests good, but something is incorrectly configured at the Telco.
The usual cause of inability to dial problems is a Telco problem, such mis‐programming.
If you are convinced that the problem lies with the ISDN line configuration, you may be able to
convince the Telco to have an engineer look at the line with an analyzer. This works much like
the Zephyr Xstream’s internal analyzer, but with more detail, and in a format that is more
readily understandable by telephone people. This procedure may sometimes be the only way to
get attention to a line configuration problem. It is hard to deny evidence provided by their own
gear.
In rare cases, there could be a software bug in the Zephyr Xstream that reacts badly to
something coming from the ISDN line. Telos customer support will need the details about your
lines, Zephyr Xstream version and configuration. They will probably need you to use the
protocol analyzer and a PC to make a log of the problem and will then communicate this
information to our engineering folks for analysis. It is critical that you give them a precise
description of exactly what happens when the problem occurs, and at what point in the log we
should focus our efforts (i.e. the problem happened 45 minutes after we began this log). We are
happy to help, but we must rely on your eyes and ears to help you.
See Section 12 (System Functions and Remote Control) for information on connecting to the
Xstream’s serial or Ethernet port and using the command line interpreter to turn on ISDN
logging. The most useful logs to enable for this purpose are “ISDN”, il2, il3, and iie.