An "errored second" (ES) is a second-long period where at least one error occurred. A "severe errored second" (SES) is the same second-long period where a severe number of errors occurred. Something like 30% of the blocks transmitted within the period are faulty.
So broadly, an ES just indicates that something happened (such as one or more CRC error), while an SES indicates that something very concentrated happened. Some ES, without SES, is perfectly natural.
podman - you mention "ongoing errors on the line", and show the increase over 2 hours. Which errors on there are you looking at, to get worried about? Or are there worse examples in your archive?
The FEC aren't errors - they are small blocks of data that the "forward error correction" process has fixed. The number is high, but your line is coping with the stuff just fine. FEC is enabled at the same time as interleaving, so it certainly appears that you want to leave that turned on!
The CRC are proper errors. These are the cases where something happened badly enough that FEC couldn't fix things, and require a (larger) block of data to be resent. You're getting about 40 an hour there, which is not massively significant, about 0.02% I think. The strange thing is that your ES counter isn't increasing. I suspect your router is not counting all the stats properly, which is an unfortunately common experience.
Note too that there is a scale difference. FEC blocks are much smaller than CRC blocks, I think 68x.
But overall, those don't seem to be bad numbers, that would have a bad effect on PPP.
My line (without interleaving) runs at about 8 CRC errors per hour, and 6 ES per hour, with no SES. But very occasionally, I can get a huge burst of CRC errors - last month the worst was a burst in a 15 minute window of 850 CRCs with 130 ES and 5 SES. But there were no obvious effects on the connection.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
