The connection between the UPC type plug and the APC type socket can cause issues due to the difference in the angle of the surfaces; therefore, there will be incomplete physical contact resulting in an air gap at the interface. SC APC SFP modules are increasingly used in optical networks where signal precision, low reflection, and long-distance stability are critical. Unlike standard SFP transceivers with UPC connectors, these optical modules integrate angled physical contact (APC) interfaces to significantly reduce back. While this was only a minor issue, it greatly affected both the optical alignment and, as indicated by test results in the field, return loss, which ideally should be approximately -65 dB, increased to 20 dB or more because of light reflecting into transceiver modules. However, early deployment challenges around 400GBASE-SR8 due to reflection sensitivity resulted in a network operator. This chapter provides a description, severity, and troubleshooting procedure for each commonly encountered Cisco NCS 1010 optical application alarm and condition. When an alarm is raised, refer to its clearing procedure. Default Severity: Minor (MN), Non-Service-Affecting (NSA) Logical Object: OTS. The AP9631 came with firmware 6. The latest is SFSUMX708, which explicitly lists “SmartUPS” and “AP9631”. So I downloaded it and ran it on my Windows VM. What resulted was a failure: [01/28/2023 13:36:15] Unable to update device 192.