Cyclic Redundancy Check (CRC) alignment errors or CRC/Align errors occur in digital networks during the process of error detection. CRC is an error-detecting code that is used to detect accidental changes to digital data. Standard test method used primarily in aerospace and spacecraft applications to evaluate how much an epoxy material outgasses in a vacuum environment to ensure they meet the total weight loss (TML) and condensable volatile material (CVCM) thresholds. I have never seen a case where it's ok to have CRC errors, although I have had some edge cases where I don't care enough to fix it, but they are really rare and to end stations, not network transit links. Fiber transports a ton of data in seconds which requires precision, therefore knowing which measurement to use is paramount. In such cases, replacing the interface, optical module, or cable should be considered to rectify the problem. CRC errors typically occur when Ethernet links are compromised due to optical fiber degradation, weak optical signals, bad optical connections, or problems on a third-party networking element. As well, higher-layer OAM options such as EFM and BFD may not detect errors and trigger appropriate alarms.
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