Cisco MGX 8200 Series Edge Concentrators

Cisco/StrataCom Field Notice 971227: AXIS on Internal Clock instead of Inband Clock

December 24, 1997

Products Affected

This field notice affects the following products:



  • AXIS BNM-155

Problem Summary

An oscillator and Programmable Logic Device (PLD) anomaly in the AXIS Broadband Network Module (BNM) is causing the shelf to stay on internal clock rather than the inband clock.

View bug details for CSCdj12714 (registered customers only)

Problem Symptoms

On the AXIS, the dspclksrc command screen shows current clock source as internal oscillator. Frame slips will occur if the EclipteK® clock is on the BNM.

Releases Where Fixed

  • BNM-T3 hardware revision "BC".

  • BNM-E3 hardware revision "AB".

  • BNM-155 hardware revision "AB".

Problem Details

AXIS was on an internal clock. Configuring the current clock source to Inband T3 failed and the BNM stayed on internal. There are two causes of this problem:

  1. An unreliable crystal from EclipteK® is being used.

  2. There is a bug in the PLD on the BNM card.

The complete fix is to use a more reliable crystal from Saronix® together with a fix in the PLD. The fix in the PLD is already in place for BNM-155 (AXIS 4.0) and will be rolled back to BNM-T3 and BNM-E3.


The workaround is to do a switchcc and reconfigure the clock using the cnfclksrc command to be inband.

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: