Performing Telephony Service Cutover
157
3.
Determine the offhook voltage by issuing the
SHOW POTS
ETM
Command while the line is offhook (in the dialing or talking phase).
Depending on the polarity and characteristics of the line, the voltage
values may be positive or negative and they may fluctuate slightly.
4.
Set the
POTS HOOK THRESH <
channel
> <
lower
>
<
upper
>
voltages such that the offhook voltage is bracketed, and the onhook
voltage is outside of those thresholds. Use magnitudes (disregard sign)
when setting the threshold values.
For instance, suppose the onhook voltage is -48V and the offhook
voltage is -7V. Set the hook threshold values to 4 and 10 (brackets the
offhook value, 7, and excludes the onhook value, 48) using the
command
POTS HOOK THRESH <
channel
> 4 10
, followed by
the command POLICY CONFIG UPDATE. If the onhook voltage is
10V and the offhook voltage is -15V, set the threshold voltages to 13V
and 17V (brackets the offhook value, 15, and excludes the onhook
value, 10).
If the onhook and offhook voltage magnitudes are very close together,
contact SecureLogix Customer Support to determine the proper
threshold values or other necessary actions.
Depending on the line characteristics and signaling type, the threshold
values may need to be tweaked to properly follow hook state
throughout the call. The
POTS DEBUG
ETM Command can be used
from the Console port to display the voltage values (to the Console
connection or in an Appliance debug log) that are used by the software
throughout the life of a call. Determine basic values using the method
specified above, and then verify the settings by making various test
calls that act in different ways (inbound calls, outbound calls,
unanswered calls, calls using pulse digits, and so forth). If any of the
calls are not detected properly, the
POTS DEBUG ETM Command
output can be used to determine the voltages reported at various stages
of each call. You can then set the threshold values to include or exclude
these values as appropriate. If this method still does not resolve the
problem, contact SecureLogix Customer Support for assistance in
determining the appropriate values.
IMPORTANT
Failure to properly connect tip and ring according to
the pinouts for these cables may impair operation. Refer to "Connectors
and Pinouts" on page 169 for correct pinouts.
You can set the
threshold values for a
specific channel by
specifying the channel
number, or type ALL to
apply the values to all
channels.
