Excalibur ISX 5312, Operation Manual

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Excalibur ISX 5312/5314 T-1 Multiplexer Installation and Operation
4-12
Clock Tolerance
The Clock Tolerance parameter specifies whether the ISX 5312/5314 automatically
switches to a lower-priority transmit clock source when the primary source is out of the
user-specified tolerance range. The available options are
Dsabl and Enabl . When this
parameter is enabled, the unit automatically switches to the fallback clocks in the order
designated under the Transmit Clock parameters. When a higher-priority clock recovers,
the unit does not switch to that timing source. The higher-priority clock source must be
selected manually from the T7 or SNMP manager’s console or from the ISX 5312/5314's
front panel. (Refer to "Transmit Clock" previously described in this chapter for
instructions.)
Note: It is recommended that you do not enable the Clock Tolerance parameter until an
installation is stable.
Tolerance Limit
The Tolerance Limit parameter allows you to select the clock tolerance range limit. The
available options are
50
(+50 Hz),
100
(+100 Hz),
150
(+150 Hz), and
200
(+200 Hz).
The range specified in AT&T Publication 62411 is +50 Hz at +32 ppm.
Busy Signal Bits
The Busy Signal Bits parameter allows you to select the 4-bit per unit DS0 channel
signaling code used in the trunk processing function. Trunk processing refers to the
ability to send signaling bits to adjacent units, indicating a particular condition (e.g.,
a busy signal) whenever an abnormal condition occurs on a T-1 interface. This
parameter appears only for units equipped with two T-1 line interfaces. The selected
code is used by both T-1 lines on the unit.
The default code (
1111
) is Four Wire Ear and Mouth (4-W E/M). To change to another
code, such as FXS (Foreign Exchange Station) or FXO (Foreign Exchange Office), enter
the appropriate combination of 0s and 1s.
The trunk processing feature operates only when the lines are cross-connected. (Refer to
the "Daisy Chain" section in this chapter for a complete description of cross-connected
and daisy-chained lines.)
Access Protection Capability
The Access Protection Capability (APC) parameters allow you to interface the ISX
5312/5314 with Accunet’s T1.5 APC service function, which provides the automatic
transfer between two Accunet T1.5 access facilities when one T-1 line fails. These
parameters appear only for units equipped with two T-1 line interfaces.