Are these error rates normal?

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nyahoo
Posts: 3
Joined: Wed Mar 06, 2013 9:28 am

Are these error rates normal?

Post by nyahoo » Wed Mar 06, 2013 10:10 am

Hi all,

I'm hoping someone can help me as a relative novice in this area. I just picked up a 7800DXL as I wanted gigabit wired connections and my line has been know to be a little unstable at times in the past, and I had heard good things about the billion routers and their ability to hold on to signals. All seems good so far, it's connecting at pretty much the highest speed I've ever managed on this line and doesn't seem to drop (although judging by the connection times in the log it obviously is on occasion and I just haven't noticed yet). However, when I look at the staus pages for xDSL, I can see a lot of errors in the section about super frames and rs words etc. My question would be is this normal? Or should I be doing something like tweaking the SNR to try and get the number of errors down. I have run the xDSL ber test and it seems to come out with the right result according to the manual, so just wondering if someone can enlighten me really please?

The current stats it is showing are;
Super Frames 24691817 21706926
Super Frame Errors 342528 1483
RS Words 2503318 359255
RS Correctable Errors 16788 0
RS Uncorrectable Errors 498 0
HEC Errors 149076 10816
OCD Errors 0 0
LCD Errors 0 0
Total Cells 11588158 958855
Data Cells 294978 37883
Bit Errors 0 0
Total ES 8582 227
Total SES 4325 36
Total UAS 667 667

SNR is set to 3.1 currently.

Thanks for any help or advice you guys can give!

Nyahoo

swatboy79
Posts: 110
Joined: Tue Jan 29, 2013 12:08 pm

Re: Are these error rates normal?

Post by swatboy79 » Wed Mar 06, 2013 10:46 am

Doesn't seem too bad, as your SNR gets lower there will be more and more errors, hopefully all corrected.

I have seen way worse on my connection running below 1db and still works fine and no issues with stability / download rates.

Eventually if there are too many errors you will find your ADSL line will resync.

Unless you are sync bad ping times / too many lost packets i wouldn't worry at all.

nyahoo
Posts: 3
Joined: Wed Mar 06, 2013 9:28 am

Re: Are these error rates normal?

Post by nyahoo » Wed Mar 06, 2013 11:13 am

Thanks for the information and the quick reply, much appreciated!

Philip_L
Posts: 111
Joined: Mon Jun 25, 2012 10:06 am

Re: Are these error rates normal?

Post by Philip_L » Thu Mar 07, 2013 6:17 pm

Hi

Just to add.

ADSL is designed to run with a certain amount of errors, it is just collateral for being able to push so much data down old copper wires. Some people will get more than others, but everyone will get some errors.

Not all those errors will impact your data. ADSL sort of runs like a commuter train, even if there is no data the packets still go back and forth, so most of those errors probably corrupted empty packets.

ADSL has no means of re-requesting data that is received damaged, that happens higher up in your computers networking, so data received corrupted will be re-requested as part of the TCP/IP transaction, so you don't see this damaged data arrive at your computer. Too many errors of course will slow things down a lot, although ADSL normal starts dropping the connection/sync when errors get bad.

A little trick I use to see what the errors are like is take the super frame errors / total super frames * 100 to get a percentage. In your case you are running at around 1.4% error rate, in comparison my line is 0.017. I would say anything less than 1 is really good and the ideal aim, and your rate is a little higher than the ideal but reflects your line which is unstable at times.

You could increase the SNR which would reduce your error rate and make the line more reliable but at the cost of speed.

If you are happy with how it is working, then I wouldn't worry.

Regards

Phil

nyahoo
Posts: 3
Joined: Wed Mar 06, 2013 9:28 am

Re: Are these error rates normal?

Post by nyahoo » Fri Mar 08, 2013 2:44 pm

Thanks so much for the long and detailed reply, very informative and much appreciated! I will try upping the SNR a little and try out your equation again to see if I can get something nice and balanced.

Thanks again!

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