Broadband Performance .... sucks!

Hi Y'all,

Looking for some advice from the better informed ... well ... hopefully!

I'm at the end of a loooong 5km+ line, and have finally settled on a Billion modem that gives me the option to tweak SNR to get the best from my poor bandwidth.

I now sync at ~1300kbps ... yup ... that's the best I can achieve. Stable line though and rarely get a disconnect.

Problem is that lately although I'm syncing at over 1mbps, browsing has been horrendously slow. Worse than dial-up with pictures taking forever to appear and even text based web pages slooooowly appearing line by line.

When I see these problems I'm monitoring bandwidth usage on the modem, and the weird thing is that it's only showing 30-50kbsp usage ... but this is not borne out by the web performance.

Any ideas peeps, I'm getting a bit hacked off with this ....

Cheers,
Ripface

Full modem stats please especially CRC, FEC and error seconds.

Ian

Seconded we need stats.

And a link to a speed test result from http://www.thinkbroadband.com/speedtest might help too

Thanks ian007jen, stats from my modem ... not the prettiest but it's all there ....

xDSL
Mode ADSL_G.dmt
Traffic Type ATM
Status Up
Link Power State L0
Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 0.7 7.0
Attenuation (dB) 63.5 31.5
Output Power (dBm) 15.9 12.1
Attainable Rate (Kbps) 1536 540
Rate (Kbps) 1376 384
K (number of bytes in DMT frame) 44 13
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 4.00 4.00
D (interleaver depth) 8 2
Delay (msec) 8.00 8.00
INP (DMT symbol) 0.33 0.03
Super Frames 93454759 93454759
Super Frame Errors 11137350 79052
RS Words 1588712858 128745807
RS Correctable Errors 1243156809 81726
RS Uncorrectable Errors 22395893 0
HEC Errors 16845168 112850
OCD Errors 848 0
LCD Errors 848 0
Total Cells 860770616 0
Data Cells 399479420 0
Bit Errors 1320678914 0
Total ES 1254176 0
Total SES 139712 0
Total UAS 128192 68

Initial comments:

Downstream SNR is at 0.7 dB and that itself is not good. When down at that level a lot of errors can occur which results in retransmissions and error correction which effectively slows the overall speed.

If you have control yo need to get that back to over 3dB - that should significantly reduce te errors and whilst the sync speed is lower the successful throughput could be higher.

Agreed, unless the low ant and heavy errors are REIN related maybe ? I looked but couldn't see an uptime in amongst those stats.

Could just be a storm or other event forced a low sync with upload particularly impacted, and since modems don't resync to improve speeds but rely on the human deciding an appropriate time to time an attempt to improve sync then until modem was 'reset' it would have continued.

Or put another way - always try a simple off, count to 10 and then on again test, if speeds have been slow for a day or two.

ES - 1254176 which converts to 348 hours if every second was errored. So it has been up for over 15 days,

The AS line comes later in the same stats.

As everybody else mentions...your SNRM downstream is far too low and causing errors......

Hi All,

Thanks for all the good suggestions. In the past I have played with the SRN tweak to get the SRNM down, thinking the lower the better. My BRAS profile has been steadily increasing to a max of 1.3mbps ... used to be down at between 500 and 800kbps.

I have eased up on the SNR tweak, and the SNRM is now sitting at 4. Will monitor and see if this helps improve the browsing experience.

FYI the uptime for when the stats were taken was 16 days. I take regular speed tests with the BT checker and it usually reports just over 1mbps down and 300kbps up.

Cheers,
Ripface

Edited by deleted (Wed 21-Jun-17 18:37:28)

Speed test results ... go on ... have a laugh!

https://www.thinkbroadband.com/speedtest/14980667564...

: (

Your line is very long, is there no fibre available? Have you checked?

: )

Yes, I've checked, checked and checked again. Our local cabinet got upgraded to FTTC two years ago, but unfortunately it was sited *right* next to the old cab and is too far away for an effective service.

I've pestered, prodded and poked BT over the years with requests for upgrades to no avail. I'm stuck with what I'm stuck with ... unless I go Satellite ... which costs an arm and a leg!

Cheers,
Ripface

Hey All,

Browsing does seem improved after backing off the SNR tweak settings. Now sync'ing at 1248kbps down and 416kbps up.

Before: Approx: 43867 HEC / Hour (Down) 294 HEC / Hour (UP)


After: Approx: 6322 HEC / Hour (Down) 58 HEC / Hour (UP)


So an order of magnitute improvement in HEC errors ... and SuperFrame Errors seem reduced too. Will monitor for a week or so and see how it goes.

SNRM is between 3 and 4, is it worth dialing back the SNR tweak again do you think??

Cheers,
Ripface.

Edited by deleted (Thu 22-Jun-17 19:14:59)

The FTTC twin always has to go near the original telephony cabinet - it has to be within 100m. What you would need is a network rearrangement which is quite expensive to do or you are waiting for new technologies - BT may well start to rollout FTTP or other options for people in your situation in the future.

I would personally do no manual tweaking of the noise margin as all providers have DLM built in which should theoretically choose the best option for your line.

If your line can support 3db you'll end up there, or alternatively at 6db, 9db etc. We are only guessing as to what is the best given the length of your line.

Typically speaking lines of your length need at a minimum 6db but often 9db to perform reliably.

You do lose speed although as you have found forcing the noise margin low only results in more errors and even slower real world performance.

Hey ukhardy07,

Thanks, I'll leave it well alone for now ... considering that I've improved the "user experience" we'll monitor it over the next week or so and see how it goes.

It'll be interesting to see how my BRAS profile reacts to the SNR tweak change. It was up at 1.3mbps for a while so will keep an eye on that.

Cheers,
Ripface

Latest BT Speedtest: IP Profile 1.21mbps


FAQ


1. Best Effort Test: -provides background information.

Download Speed
1.11 Mbps

0 Mbps 2 Mbps
Max Achievable Speed

Download speedachieved during the test was - 1.11 Mbps
For your connection, the acceptable range of speeds is 0.8 Mbps-2 Mbps.
IP Profile for your line is - 1.21 Mbps

2. Upstream Test: -provides background information.

Upload Speed
0.23 Mbps

0 Mbps 0.45 Mbps
Max Achievable Speed

Upload speed achieved during the test was - 0.23Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.45 Mbps

Edited by deleted (Sat 24-Jun-17 20:26:31)