The Building Integrated Timing Supply (BITS) input on the 15327-MIC-28-3-A and 15327-MIC-28-3-B may have problems synching with a BITS source if that source is connected to the 15327 BITS input with a cable length that exceeds 35 feet. This will not be an issue with cable lengths less than 35 feet or on systems where external timing is not utilized.
This issue was identified as a mechanical issue and was corrected, verified, and implemented in the manufacturing process.
In a system where the timing is derived from the BITS input on the 15327-MIC-28-3-A or 15327-MIC-28-3-B, distortion of the timing signal through the RJ45 connector can affect the ability of the ONS 15327 to lock to the timing source, especially in cable lengths exceeding 35 feet. This could result in the inability to synch to the external timing source provided through the RJ45 connector.
No action is required by customers utilizing line timing or using a timing source that has a cable length less than 35 feet where timing has synched to the external source.
Customers that require BITS timing utilizing the BITS input on the MIC board should contact Cisco's Technical Assistance Center (TAC) to request a Return Material Authorization (RMA).
This root cause of this issue has been identified and a fix has been implemented in a design change that is implemented in all subsequent versions of these boards starting with 800-07399-03 A0 for the 15327-MIC-28-3-A and 800-07666-03 A0 for the 15327-MIC-28-3-B.
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: