Field Notice: FN74156 - DP04SFP8-E20 Might Experience Performance Degradation - Replace on Failure

Available Languages

Updated:June 24, 2026
Document ID:FN74156

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

Medium
Impact Rating:
Medium
First Published:
2024-Oct-08
Last Published:
2026-Jun-24
Revision:
1.1
Cisco Bug IDs:

Notice

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Products Affected


Affected Product Name Description Comments
DP04SFP8-E20= 400GBPS COHERENT OSFP, DWDM C-BAND TUNABLE 400ZR MODULE  




Defect Information


Defect IDHeadline
CSCwm41611Acacia PID, DP04SFP8-E20/DP04SFP8-E20=, Optics Alarms and Failures Post A0 Release and Fixes

Problem Description


A limited number of DP04SFP8-E20 optics, as listed in the Products Affected section, might experience performance degradation and exposure to higher temperatures. This could result in optics alarms and failures.


Background


Due to a defect in the capacitor manufacturing, internal leakage current is observed in the optics.


Problem Symptom


Customers may experience degrading bit error rate (BER) and deteriorating accuracy of the coherent channel power monitoring. Eventually, BER will degrade enough to cause link failure.


Workaround/Solution


Solution

As corrective action, Manufacturing has switched to an alternative capacitor vendor to be assembled in the optics. Optics that are currently shipping already have the fix incorporated.

If the optics exhibit the symptoms that are described in this field notice, verify the serial number using the Serial Number Validation Tool. If the unit is confirmed as affected, replace the optics upon failure.


How to Identify Affected Products


Check the product label of the optics for the serial number. Enter the serial number in the Serial Number Validation Tool to see if it shows as affected.


Serial Number Validation


The Cisco Support Assistant (CSA) can help verify whether a device is impacted by the issue that is described in this Field Notice. To check the device, either enter the serial number in the CSA on the right side of this page or click the following URL: Cisco Support Assistant

Revision History


VersionDescriptionSectionDate
1.1Updated recommendations.Workaround/Solution2026-JUN-24
1.0Initial Release—2024-OCT-08

For More Information

For further assistance or for more information about this field notice, contact the Cisco Technical Assistance Center (TAC) using one of the following methods:

Receive Email Notification About New Field Notices

To receive email updates about Field Notices (reliability and safety issues), Security Advisories (network security issues), and end-of-life announcements for specific Cisco products, set up a profile in My Notifications.

Was this Document Helpful?

FeedbackFeedback

Contact Cisco