April 11, 2000
Cisco ONS 15454
If a working Timing Communications and Control (TCC) card, Cross Connect (XC), or Cross Connect Virtual Tributary (XCVT) is physically removed from the Cisco 15454 (Cerent 454), traffic running on the DS3-12 card could possibly degrade and cause an outage. The problem is random; that is, it may affect one DS3-12 card or all the cards plugged in to the shelf.
The DS3-12 card receives its timing from three sources: the two TCC cards and the current XC or XCVT. To run traffic correctly, the DS3-12 card needs to receive timing from the XC or XCVT that is active. If a TCC, XC, or XCVT is pulled from the shelf, the DS3-12 card may select the wrong timing source.
This problem can also occur when an DS3-12 card is first plugged in to a shelf.
DS3 traffic running on the card will start displaying DS3 framing errors and may possibly go into Alarm Indication Signal (AIS).
Do not remove the TCC, XC, or XCVT cards in the shelf. If you have to remove one of these modules, reset all the affected DS3 modules in the shelf from the Cerent Management System (CMS) shelf view. After you initially plug in a new DS3-12 module, reset the card from the CMS shelf view.
For More Information
If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: