Communication Failure

This alarm indicates that a card or ONT could not be communicated with and has failed sanity messages. This alarm is raised on cards within the Tellabs OLT chassis or on ONTs and indicates the card or ONT is known to be present but cannot be communicated with.

If this is a recurring problem that is resolved by a remote reset, it should be referred to the Tellabs Technical Assistance Center (refer to Contacting Technical Support for further analysis. Note that if this is an ONT and it is in eSTOP and has this alarm, the ONT has been found to be oscillating in and out of sync on the PON.

Trouble Clearing

• Network Issue: It may be possible that the network between the ESU and OLT has an issue blocking communication between the ESU and EMS.
  • See Procedure:  Network Issue Troubleshooter
• Certificate Issues: Certificate issues can cause issues communicating between the OLT and EMS.  This typically can only happen when custom certificates are used.  All Tellabs OLTs and EMS'es have self signed certificates that are compatible.  If you have a custom certificate you should ensure that your certificates are valid on both the OLT and EMS.  Please note that the OLT must first be pingable before certificate issues can arise, make sure the OLT was pingable in the previous step.  If it was not pingable see the steps below.
  • If the OLT is pingable and you have custom certificates, go to the Certificate Troubleshooter to validate the certificates.
• Software Issue: It is possible that the card has a software issue and is not communicating with the system.  Attempt the following steps to address it: 
  • Remote Reset Line Card / ONT: A Cold Reset of the card / ONT may resolve the issue by restarting the software. All cards / ONTs have a right-click menu that allows remotely resetting the card / ONT.  If this happens consistently, it should be reported to TAC.
  • Remove / Reseat Line Card / ONT: A small subset of problems may require the card to be physically removed and then reinserted. If this is an ONT, cycle power to the ONT.  If this happens consistently, it should be reported to TAC.  
• ESU Hardware Issue: A hardware failure on the ESU could cause a loss of communications.
  • ESU Card Replacement: If there is a hardware failure, you may need to replace the ESU card.  Contact TAC for advance replacements if your contract supports this.

OLT Line Card Reset

The OLT line cards can be reset by right clicking on the line card in the common tree, right click and select the Properties Line item and then selecting reset.

ONTs can be reset in a similar way by right clicking on the ONT and selecting Properties and then reset.

ONT in eSTOP: If an ONT has been oscillating in and out of sync on the PON, the system eventually places that ONT in eSTOP which places it in a standby state. The ONT is not allowed back into the system as typically it requires maintenance and may affect other ONTs on the PON.  

The status of the ONT can be determined by looking at the ONT Status tab.  If the ONT Status is ESTOPON then the ONT has been either disabled by a user or disabled by the system due to excessive arrivals.

If an ONT is being placed in eSTOP it is due to that ONT arriving and departing to frequently on the PON.

This can be caused by: 

• Problems with the ONT hardware, or the fiber which result in a high BIP error rate.  If this ONT consistently gets eStopped, likely it needs to be replaced or fiber maintenance needs to be performed.
• A different faulty ONT transmitting outside its transmission window and causing this ONT to be eStopped.

If the failed unit is an ONT then perform the Optical Trouble Shooting procedure (refer to GPON Optical Troubleshooter) to ensure no optical problems exist in the path. Then remove the eStop on the ONT using the EMS GUI. This allows the ONT to retrain on the PON. If the optical path is working properly, and the alarm still exists, replace the ONT (refer to the appropriate ONT Description and Installation User’s Guide).