What causes FEC errors?

[#1]

I had a stable connection untill last night and had just over 3 million FEC errors over a 24 day period after the disconnection last night I have now got 39 million FEC errors over a 17 hour period. I was just wondering what could cause this. Just to confirm nothing has been changed. See stats below.

Uptime: 24 days, 2:55:06
DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 440 / 7,880
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 4.00
Output Power (Up/Down) [dBm]: 12.5 / 0.0
Line Attenuation (Up/Down) [dB]: 20.0 / 43.5
SN Margin (Up/Down) [dB]: 26.0 / 9.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 11 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 36 / 0
FEC Errors (Up/Down): 0 / 3,246,538
CRC Errors (Up/Down): 0 / 7,570
HEC Errors (Up/Down): 0 / 5,766
And after the disconnection.
Uptime: 0 days, 17:23:28
DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 440 / 6,647
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 12.5 / 0.0
Line Attenuation (Up/Down) [dB]: 20.0 / 43.0
SN Margin (Up/Down) [dB]: 27.0 / 10.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 11 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 94 / 0
FEC Errors (Up/Down): NA / 39,815,479
CRC Errors (Up/Down): NA / 40

[#2]

In short - I've no idea.
But I bought a new D-link router last month and from the outset the router reported loads of FEC errors and frequently disconnected. So I sent it back and replaced it with a different brand and the connection has been rock solid since with no FEC errors at all.
That led me to believe it was a router problem but I'm not technical enough to know for sure.

[#3]

Having googled it, it is do do with the line rather than the router and apparently nothing to worry about.

[#4]

Better insight here...http://www.kitz.co.uk/adsl/linestats_errors.htm

[#5]

Quote

and apparently nothing to worry about.

Yes when they are reasonable number e.g your 3 million in 24 days. However your 39 million in 17 hours, together with the fact that the line has synched 1mb slower than previously ( which should reduce errors! ) tends to indicate a problem somewhere.

[#6]

I thought this could be a problem but no idea what. My router is plugged into the master socket and I have no extentions just one phone into the master socket. Tried unplugging phone for a few hours but still getting lots of FEC errors can only assume somthing to do with bt line or router. Will give it a couple of days then try rebooting my router which by the way is the ST supplied by Plusnet and is only 3-4 months old.

[#7]

Quote

My router is plugged into the master socket and I have no extentions just one phone into the master socket.

Do you have any extension wiring ? even if there aren't phones plugged in extension wiring can cause problems.
If you have extension wiring then try removing the Master socket lower faceplate and connecting to the test socket behind it, that will disconnect any extension wiring.

[#8]

No there's no extention wires at all from the master socket. I've just a phone and my router.

[#9]

I suggest you watch whether the (down) SN Margin changes with time of day. I had a horrendously noisy phone extension. My Noise Margin was changing by over twelve decibels between daylight and night hours. (It might have plunged more, but my DSL would drop and reconnect with lower sync speed.) The rate of FEC/"correctable" (which means in reality, corrected) errors started to rise rapidly as the Noise Margin dropped. Perhaps your millions happened in hours of darkness when the Noise Margin was not what you see as a daytime value.