Cisco Systems 78-16845-01 Setting Up Internal Timing for CTC-Based SDH NEs, Internal Clock, 3-63

Chapter 3 Building the Network

3.10.2 Synchronization Settings for the ONS 15454 SDH and ONS 15600 SDH

Note Refer to the Cisco ONS 15454 SDH Troubleshooting Guide or Cisco ONS 15600 SDH

Troubleshooting Guide for timing-related alarms.

3.10.2.2 Setting Up Internal Timing for CTC-Based SDH NEs

If no BITS source is available, you can set up internal timing by timing all nodes in the ring from the internal clock of one node.

Caution Internal timing is Stratum 3 and not intended for permanent use. All nodes should be timed to a Stratum 2 or better primary reference source.

Step 1 Select an ONS 15454 SDH or ONS 15600 SDH NE and choose Configuration > NE Explorer.

Step 2 In the node property pane, select the Timing tab.

Step 3 In the General Timing section of the General subtab, enter the following information:

•Timing Mode—Choose External.

•Revertive—Not applicable for internal timing; the default setting (checked) is sufficient.

•Reversion Time—Not applicable; leave unchanged.

Step 4 In the BITS Facilities section of the General subtab, enter the following information:

•E1, T1, 2.048 MHz, 64 KHz—Choose E1, T1, 2.048 MHz, or 64 KHz depending on the signal supported in your market. For example, 64 KHz is used in Japan. E1, 2.048 MHz, and 64 KHz are physical signal modes used to transmit the external clock (from a GPS, for example) to BITS.

•In State— Set BITS 1 and BITS 2 to OOS.

•Out State— Set BITS 1 and BITS 2 to OOS.

• State (Applicable to the ONS 15600 SDH)—Set BITS 1 and BITS 2 to OOS.

•Coding—Not relevant for internal timing; the default is sufficient.

•Framing—Not relevant for internal timing; the default is sufficient.

•Sync Messaging—Checked automatically. SSM is used to deliver clock quality. The SSM supported in SDH is G811, STU, G812T, G812L, SETS, DUS (ordered from high quality to low quality). If you selected 2.048 MHz or 64 KHz, the SSM option is disabled.

•AIS Threshold—Not relevant for internal timing.

•LBO—Not relevant for internal timing.

•Sa bit—Not relevant for internal timing.

Step 5 In the Reference List subtab, enter the following information:

•	NE References
	–	Ref-1—Set to	Internal Clock.
	–	Ref-2—Set to	Internal Clock.
	–	Ref-3—Set to	Internal Clock.
•	BITS 1 Out/BITS 2 Out (Applicable to the ONS 1545 SDH)—Set to None.
			Cisco Transport Manager Release 6.0 User Guide
78-16845-01				3-63