Timing Problem

Description

Signals failure of the timing source for the shelf. If the shelf is a timing server, then the problem is with the Composite Clock input on the 1134 shelf or the TDU faceplate. If the shelf is a timing client, then it indicates failure of the timing packet stream from the server.

The settings for client/server can be determined by looking at the Timing configuration in the Network Element properties. Select the NE in the Common Tree, then right-click the ONT and select Property. Open the Timing tab.

Server Trouble Clearing

The probable causes of this alarm are: 

• Composite Clock not Attached: The system requires a 64kb/s Composite clock signal to be attached to the Tellabs 1134 faceplate or the Tellabs 1150 TDU faceplate. This clock is used to time all voice services. Without a composite clock source the system cannot faithfully transfer Fax and Modem transmissions and they may fail if the clock is absent. 

  Note: It must be a 64kb/s Composite clock, DS1 BITS clock sources are not accepted by the system.

  Attach a Composite Clock Source (refer to Replace a Timing Distribution Unit (TDU1) or Replace an Ethernet Switch Unit (ESU30 or ESU32).

• Composite Clock Failed: The office clock may have failed. Look at the other systems in the CO that are wired for Composite Clock and verify that the External Timing LED is on. If it is, then the office clock is likely still good. If other OLTs experience the same failure, the problem is likely the office clock.
• Termination Resistor Missing: The office clocks are often daisy chained from system to system in most installations. The last OLT in the chain MUST have a 133-ohm termination resistor to ensure that the clock signal remains clean and suitable for use.
  
  Install Termination Resistor (refer to Replace a Timing Distribution Unit (TDU1)  or Replace an Ethernet Switch Unit (ESU30 or ESU32)).

Client Trouble Clearing

The probable cause of this alarm is: 

• TDU or ESU30 Failure: If the network is verified as good and that the server is reachable, it is possible that the timing client hardware is bad. On the Tellabs 1150 shelf, this is on the TDU1 card. On the Tellabs 1134 shelf, this hardware is on the ESU30 card. Replace the TDU1 or ESU30 card (refer to Replace a Timing Distribution Unit (TDU1) or Replace an Ethernet Switch Unit (ESU30 or ESU32)).
  
  
  
  The diagram above shows the typical timing architecture. Redundant composite clock inputs are attached to the TDUs (Tellabs 1150 MDS5 shelf) or ESUs (Tellabs 1134 shelf). Timing is distributed to remote elements via a packet stream which contains timing information for all the other OLTs.

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