@audphile1 your analogy about the peanut butter? That is not how it works. There's no cleaning up at all. While I perhaps don't agree with with @12many 's analogy, and he even said it wasn't his strong suit, The better way to explain I think is that you have small child's toy, round holes, square holes, star holes, and triangle holes. Those are your 4 options with a PAM4 encoded signal like Ethernet. From a protocol perspective, as the PAM4 encoded signal comes across the wire, it fits in one of the holes, that's it. There is no option for peanut butter. All these signals coming through each hole is then assembled into a frame. Once the frame is complete, a CRC check is don't on the frame, and if the checksum doesn't match, the frame is completely discarded. No noise. There is no cleaning up. In a residential setting this is very rare, may happen once or twice per year that one frame is lost. So you can have your disagreement, but it is not rooted in facts.