> That's why TCP (or maybe it's Ethernet?) frames include FEC bytes in their message format.
Neither TCP nor Ethernet provide for forward error correction. Ethernet frames include a 32-bit CRC while TCP segments use the so called "internet checksum".
IEEE 802.3, the ethernet working group, defines FEC for many media types. While Ethernet frames do not themselves contain forward error correction, in many cases they are encoded with FEC before they hit the line. This is required by spec for most long low speed and all high speed links. You couldn’t get any frames through without it.
Neither TCP nor Ethernet provide for forward error correction. Ethernet frames include a 32-bit CRC while TCP segments use the so called "internet checksum".