Cisco ONS 15454 Series Procedure Manual page 486

DLP-A69 Set Up External or Line Timing
Quality of RES—If your timing source supports the reserved S1 byte, set the timing quality here.
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(Most timing sources do not use RES.) Qualities are displayed in descending quality order as ranges.
For example, ST3<RES<ST2 means that the timing reference is higher than a Stratum 3 and lower
than a Stratum 2. Refer to the "Security and Timing" chapter of the Cisco ONS 15454 Reference
Manual for more information about SSM, including definitions of the SONET timing levels.
Revertive—Select this check box if you want the ONS 15454 to revert to a primary reference source
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after the conditions that caused it to switch to a secondary timing reference are corrected.
Revertive Time—If Revertive is checked, choose the amount of time the ONS 15454 will wait before
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reverting to its primary timing source. Five minutes is the default.
In the Reference Lists area, complete the following information:
Step 3
Note
NE Reference—Allows you to define three timing references (Ref 1, Ref 2, Ref 3). The node uses
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Reference 1 unless that reference fails, in which case the node uses Reference 2. If Reference 2 fails,
the node uses Reference 3, which is typically set to Internal Clock. The internal clock is the Stratum
3 clock provided on the TCC/TCC2P. The options displayed depend on the Timing Mode setting.
BITS-1 Out/BITS-2 Out—Define the timing references for equipment wired to the BITS Out pins
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on the backplane. BITS-1 Out and BITS-2 Out are enabled when BITS-1 and BITS-2 facilities are
put in service. If Timing Mode is set to external, choose the OC-N card used to set the timing. If
Timing Mode is set to Line, you can choose an OC-N card or choose NE Reference to have the
BITS-1 Out and/or BITS-2 Out follow the same timing references as the NE.
Click the BITS Facilities subtab.
Step 4
Note
In the BITS In area, complete the following information:
Step 5
Facility Type—(TCC2P card only.) Choose the BITS signal type supported by your BITS clock,
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either DS1 or 64Khz+8Khz.
BITS In State—If Timing Mode is set to External or Mixed, set the BITS In State for BITS-1 and/or
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BITS-2 to IS (in service) depending whether one or both BITS input pin pairs on the mechanical
interface card (MIC) are connected to the external timing source. If Timing Mode is set to Line, set
the BITS In State to OOS (out of service).
Cisco ONS 15454 Procedure Guide, R5.0
17-76
You can define up to three timing references for the node and up to six BITS Out references.
BITS Out references define the timing references used by equipment that can be attached to the
node's BITS Out pins on the backplane. If you attach equipment to BITS Out pins, you normally
attach it to a node with Line mode because equipment near the external timing reference can be
directly wired to the reference.
If the Timing Mode is set to External, your options are BITS1, BITS2, and Internal Clock.
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If the Timing Mode is set to Line, your options are the node's working OC-N cards and Internal
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Clock. Choose the cards/ports that are directly or indirectly connected to the node wired to the
BITS source, that is, the node's trunk (span) cards. Set Reference 1 to the trunk card that is
closest to the BITS source. For example, if Slot 5 is connected to the node wired to the BITS
source, choose Slot 5 as Reference 1.
If the Timing Mode is set to Mixed, both BITS and OC-N cards are available, allowing you to
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set a mixture of external BITS and OC-N trunk (span) cards as timing references.
The BITS Facilities section sets the parameters for your BITS1 and BITS2 timing references.
Many of these settings are determined by the timing source manufacturer. If equipment is timed
through BITS Out, you can set timing parameters to meet the requirements of the equipment.
Chapter 17 DLPs A1 to A99
March 2005