Chapter 3 Building the Network
3.10.1 Synchronization Settings for the ONS 15310, ONS 15327, ONS 15454 SONET, and ONS 15600 SONET
•Quality of RES—If the timing source supports the reserved S1 byte, set the timing quality here. (Most timing sources do not use RES.) Qualities are displayed in descending quality order as ranges. For example, ST3 < RES < ST2 means the timing reference is higher than a Stratum 3 and lower than a Stratum 2.
Step 4 In the BITS Facilities section of the General subtab, complete the following information:
Note The BITS Facilities section sets the parameters for BITS1 and BITS2 timing references. Many of these settings are determined by the timing source manufacturer. If the equipment is timed through BITS Out, set the timing parameters to meet the requirements of the equipment.
•In State—If Timing Mode is set to External or Mixed, set the In State for BITS 1 and/or BITS 2 to IS (In Service) depending on whether one or both BITS input pin pairs on the backplane are connected to the external timing source. If Timing Mode is set to Line, set the In State to OOS (Out of Service).
•Out State—If equipment is connected to the node’s BITS output pins on the backplane and you want to time the equipment from a node reference, set the Out State for BITS 1 and/or BITS 2 to IS, depending on which BITS output pins are used for external equipment. If equipment is not attached to the BITS output pins, set the Out State to OOS.
• | Coding—Set to the coding used by the BITS reference, either B8ZS (binary 8-zero substitution) or |
| AMI (alternate mark inversion). |
• | Framing—Set to the framing used by the BITS reference, either ESF (Extended Superframe) or |
| SF(D4) (Super Frame). SSM is not available with Super Frame. |
•Sync Messaging—Check to enable SSM.
•AIS Threshold (Not applicable to the ONS 15600 SONET)—Sets the quality level where a node sends an alarm indication signal (AIS) from the BITS 1 Out and BITS 2 Out backplane pins. When a node times at or below the AIS threshold quality, an AIS is sent. This is used when SSM is disabled or when the frame is SF.
•LBO (Not applicable to the ONS 15600 SONET)—If you are timing an external device connected to the BITS Out pins, set the distance between the device and the NE. Options are 0-133 ft. (Cisco default), 134-266 ft., 267-399 ft., 400-533 ft., and 534-655 ft.
Step 5 In the Reference List subtab, complete the following information:
Note Reference lists 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 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.
•NE References—Define up to three timing references (Ref-1, Ref-2, Ref-3). The node uses Reference 1 unless a failure occurs to that reference, in which case the node uses Reference 2. If that fails, the node uses Reference 3, which is typically set to Internal Clock. This is the Stratum 3 clock provided on the TCC+/TCC2 card. The options displayed depend on the Timing Mode setting:
–Timing Mode set to External—Options are BITS1, BITS2, and Internal Clock.
Cisco Transport Manager Release 6.0 User Guide
