Well, that's what I was told numerous times, but I remember having millions of FECs a minute on our old VDSL connection and the line would stay in sync for hours if not days

In reply to a post by Zarjaz:

When FEC’s are high enough, the usage can appear slow. The router will eventually drop sync looking for a better signal.

Yes, error correction of that volume will hit throughput and in cheap routers possibly even CPU load of the router.

29 million FEC's yesterday
just 107 CRC's

In reply to a post by rose123p:

29 million FEC's yesterday
just 107 CRC's

Can you isolate the power, so it is ONLY the router plugged in and switched on ? Literally nothing else. Is the heavy error count still there and incrementing ?

That proves the error correction is working well, if you didn't have it then your connection would be dropping out constantly or not even working at all. Of course, I'm not undermining the fact that there is a problem, but the error correction is helping quite a bit!

Edited by Grimers (Wed 08-Feb-23 20:10:48)

In reply to a post by rose123p:

29 million FEC's yesterday
just 107 CRC's

At mentioned FEC'sc are errors that never happened. They are corrected before they become errors.
They can sometimes indicate noise on the line but they aren't an issue on their own.

My line received 100,000+ FEC per minute, every minute, all day everyday.
I received not a single CRC/ES. The line was perfect.
When using Homeplugs (powerline adapters) FEC's would increase to 1,000,000+ per minute, every minute.

DSL is designed to have interference and error correction.
Your line isn't losing sync either. Forget about FEC's. They aren't the issue.

The issue is when the modem no longer corrects the errors and they change from FEC to CRC. Too many CRC's can cause significant packet loss or a drop in sync.

Set up a BQM. Monitor your line for packet loss. Look for other indicators in your modem stats, particularly a very low SNRM or CRC/ES.

Edited by j0hn83 (Thu 09-Feb-23 12:03:03)

FEC's were around 29-35 million per day. Oddly dropped to around 90 thousand last few days. Openreach engineer been out today and FEC's were low but hes found a earthing problem, gone up the pole and found some damp and corroded terminals. Fixed those. Hopefully fingers crossed we're all fixed now!

I highly doubt FEC on its own could cover an earthing problem, but it's good to know that's been fixed!

An earth fault is a contact fault, same as a battery fault, almost certainly accompanied by an HR at the fault location. Yes, these can cause errors.

I didn't say they couldn't, I'm just saying that FEC on its own wouldn't cover it on its own, as in be able to keep the connection in sync/stable.