Peak time speed problem - purleigh
My connection has been great since 2006, but started to have peak time speed problems since Christmas 2012.
I have reported many times my issues in the original peak time slow down thread (now locked), but I was largely ignored as it was stated that my problems were not related to the predominating issue, and that I probably had a line fault. The only thing that was ever found was that Plusnet had underestimated the 20CN capacity on an endpoint that I had been connected to, which they say they fixed - but I'm not convinced.
So I am starting again, in the hope of finding what is going wrong - as I can't see where the issue lies !
I am on the Purleigh exchange (EAPUR), and I have never seen that showing congestion or having other problems.
I have a straight line connection of approximately 500 metres from the exchange.
My connection is 20CN ADSL, G.dmt, that is 8128Kbps down, and 448Kbps up.
My ADSL gateway and telephone are plugged directly into the ADSLnation XTE-2005 filtered faceplate on the master socket, using the shortest length and highest quality cables. There are no cable extenders or extension wiring used at all.
My typical gateway stats are as follows -
The sync rates are always the same, and the other figures might move +/-0.5dB whatever the weather, and no evening droops.
The error rate currently is in the order of one or two CRC errors per day !.
In an effort to start resolving this issue from scratch, I have done the following -
1) I removed my ADSLnation XTE-2005 filtered faceplate, blew it clean with compressed air & cleaned contacts with meths.
2) Tried different ADSL cable to between the filtered faceplate and the gateway, 50cm round cat5 RJ11
3) Swapped gateways between a Draytek Vigor 2710, and a Netgear DG834GT with DGteam firmware.
4) Replaced my old BT DECT telephone with a new Siemens Gigaset N300A-IP basestation, into the XTE-2005 faceplate.
5) Temporarily used a high quality ADSL inline filter into the test socket, but have gone back to using the XTE-2005 faceplate.
- None of which made the slightest difference !.
I had a line reset applied to my connection at 16:04 on 3rd April 2013, as my exchange had only recently stopped correctly negotiating a workable target SNR, was not updating the BT line profile even with an 8128 sync steady for > 300 hours, and was reporting errors when there weren't any !.
Therefore I am currently in day six of the ten day re-training period, so for a few more days I don't particularly want to swap things around.
The SNR is now holding steady, syncing at max 8128Kbps, and the line has been stable at all times since.
Before Christmas my speedtest results were pretty much always as follows -
Since the line reset I have been achieving typically -
So there is an unexplained permanent increase in latency in the region of 10ms to 15ms.
Since the line reset, the latency remains fairly constant with low jitter - even during the evening speed slowdowns.
My ThinkBroadBand quality monitoring graph also always looks alright -
The purpose of this thread is so that I can post all my test results whenever I experience the illusive peak time slowdown !
I have reported many times my issues in the original peak time slow down thread (now locked), but I was largely ignored as it was stated that my problems were not related to the predominating issue, and that I probably had a line fault. The only thing that was ever found was that Plusnet had underestimated the 20CN capacity on an endpoint that I had been connected to, which they say they fixed - but I'm not convinced.
So I am starting again, in the hope of finding what is going wrong - as I can't see where the issue lies !
I am on the Purleigh exchange (EAPUR), and I have never seen that showing congestion or having other problems.
I have a straight line connection of approximately 500 metres from the exchange.
My connection is 20CN ADSL, G.dmt, that is 8128Kbps down, and 448Kbps up.
My ADSL gateway and telephone are plugged directly into the ADSLnation XTE-2005 filtered faceplate on the master socket, using the shortest length and highest quality cables. There are no cable extenders or extension wiring used at all.
My typical gateway stats are as follows -
ADSL driver and PHY status
Channel: FAST, Upstream rate = 448 Kbps, Downstream rate = 8128 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 11.8 23.0
Attn(dB): 9.0 5.0
Pwr(dBm): 13.8 11.9
Max(Kbps): 9536 1136
Rate (Kbps): 8128 448
The sync rates are always the same, and the other figures might move +/-0.5dB whatever the weather, and no evening droops.
The error rate currently is in the order of one or two CRC errors per day !.
In an effort to start resolving this issue from scratch, I have done the following -
1) I removed my ADSLnation XTE-2005 filtered faceplate, blew it clean with compressed air & cleaned contacts with meths.
2) Tried different ADSL cable to between the filtered faceplate and the gateway, 50cm round cat5 RJ11
3) Swapped gateways between a Draytek Vigor 2710, and a Netgear DG834GT with DGteam firmware.
4) Replaced my old BT DECT telephone with a new Siemens Gigaset N300A-IP basestation, into the XTE-2005 faceplate.
5) Temporarily used a high quality ADSL inline filter into the test socket, but have gone back to using the XTE-2005 faceplate.
- None of which made the slightest difference !.
I had a line reset applied to my connection at 16:04 on 3rd April 2013, as my exchange had only recently stopped correctly negotiating a workable target SNR, was not updating the BT line profile even with an 8128 sync steady for > 300 hours, and was reporting errors when there weren't any !.
Therefore I am currently in day six of the ten day re-training period, so for a few more days I don't particularly want to swap things around.
The SNR is now holding steady, syncing at max 8128Kbps, and the line has been stable at all times since.
Before Christmas my speedtest results were pretty much always as follows -
Since the line reset I have been achieving typically -
So there is an unexplained permanent increase in latency in the region of 10ms to 15ms.
Since the line reset, the latency remains fairly constant with low jitter - even during the evening speed slowdowns.
My ThinkBroadBand quality monitoring graph also always looks alright -
The purpose of this thread is so that I can post all my test results whenever I experience the illusive peak time slowdown !
On Friday night, 5th April 2013, I was browsing this forum and doing some eBay searches, and noticed that these simple tasks seem sluggish, so did the following speed tests to see what was going on - and discovered my speed had halved !
[quote=BTW Performance Test] Download speed achieved during the test was - 3.61 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
My router looks OK
My BTW profile is 7.15Mbps
The Plusnet profile is 7.15Mbps
I reported all this to 'Kelly', who said -
and
which looks like it resulted in my exchange being tested Monday night, as that messed up the estimated line speed !
which previously always said 8.0Mb !
Quote You are currently connected to gateway pcl-ag08.
[quote=BTW Performance Test] Download speed achieved during the test was - 3.61 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
My router looks OK
My BTW profile is 7.15Mbps
The Plusnet profile is 7.15Mbps
I reported all this to 'Kelly', who said -
Quote Loads of capacity on that end point right now so it's not congestion on our side. I can't do exchange checks from here.
and
Quote I can't see anything atm which is causing that. I'll talk to Dave on Monday
which looks like it resulted in my exchange being tested Monday night, as that messed up the estimated line speed !
Quote Phone exchange:
PURLEIGH
Estimated line speed:
2.0Mb (Accurate to within +/- 1Mbit) - Checked on 2013-04-08 21:43:46
Current line speed:
7.15 Mb
which previously always said 8.0Mb !
Tonight, the same thing happened again ! Speed had been fine all day, and then noticeable sluggish browsing !
[quote=BTW Performance Test]Download speed achieved during the test was - 2.35 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
My router looks OK
My BTW profile is 7.15Mbps
The Plusnet profile is 7.15Mbps
Quote You are currently connected to gateway pcl-ag08
[quote=BTW Performance Test]Download speed achieved during the test was - 2.35 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
My router looks OK
My BTW profile is 7.15Mbps
The Plusnet profile is 7.15Mbps
This is only a peak time problem !
It looks to me like either exchange congestion (which nobody has ever found), or my connection endpoint still has limited capacity.
I just can't see any problem with my ADSL connection.
It also bothers me that when running speed tests (during the slowdowns) that the graph of the progression of the speed tests show a particularly 'choppy' shape, whereas under normal conditions the graph is relatively flat with the odd peak.
Here are some I captured previously, although the waveforms are representative of the situation now -
It looks to me like either exchange congestion (which nobody has ever found), or my connection endpoint still has limited capacity.
I just can't see any problem with my ADSL connection.
It also bothers me that when running speed tests (during the slowdowns) that the graph of the progression of the speed tests show a particularly 'choppy' shape, whereas under normal conditions the graph is relatively flat with the odd peak.
Here are some I captured previously, although the waveforms are representative of the situation now -
So it's nearly midnight and as expected speed has returned to normal !
One of the frustrating things about doing these speed tests, is the variability of the indicated speed during the test,
when speed test plots look like this-
When the time is outside the evening peak usage range, the speed test plot ramps up to a relatively steady level and then stays pretty much at that level, with the odd small peak and trough, but for the most part is indicating instantaneous speeds which are representative of the final reported result.
However at peak times, the final reported figure seems to be based on the fastest fraction of the test duration and NOT the overall average.
This means you can be observing really bad throughput for 90% of the time and then see a 10% good burst, and only the best 10% part is recorded.
Of course sods law means that I nearly always get a good speed burst during a test.
So with the 'choppy' nature of the plots, I can often observe perhaps -
Progress - Instantaneous speed
0% - Test started
10% - 1.5Mbps
20% - 5.5Mbps
30% - 2.7Mbps
40% - 3.1Mbps
50% - 4.6Mbps
60% - 6.9Mbps
70% - 3.2Mbps
80% - 3.1Mbps
90% - 5.7Mbps
100% - Result recorded = 6.9Mbps
As all the speed test programs appear to operate in this 'best effort' manner, it makes it very difficult to show you test results of concern, which happen not to be very good or consistently bad. In Reply #1 and Reply #2 I was able to capture consecutively bad results using three different testers.
There are many times when I would like to show you results where my line is perfectly stable, but the transferred data speed is crashing from one moment to the next between slow and moderately fast, or when the test is almost at a standstill for 90% of the test only to have the 10% burst cause an unrepresentative result to be reported.
when speed test plots look like this-
When the time is outside the evening peak usage range, the speed test plot ramps up to a relatively steady level and then stays pretty much at that level, with the odd small peak and trough, but for the most part is indicating instantaneous speeds which are representative of the final reported result.
However at peak times, the final reported figure seems to be based on the fastest fraction of the test duration and NOT the overall average.
This means you can be observing really bad throughput for 90% of the time and then see a 10% good burst, and only the best 10% part is recorded.
Of course sods law means that I nearly always get a good speed burst during a test.
So with the 'choppy' nature of the plots, I can often observe perhaps -
Progress - Instantaneous speed
0% - Test started
10% - 1.5Mbps
20% - 5.5Mbps
30% - 2.7Mbps
40% - 3.1Mbps
50% - 4.6Mbps
60% - 6.9Mbps
70% - 3.2Mbps
80% - 3.1Mbps
90% - 5.7Mbps
100% - Result recorded = 6.9Mbps
As all the speed test programs appear to operate in this 'best effort' manner, it makes it very difficult to show you test results of concern, which happen not to be very good or consistently bad. In Reply #1 and Reply #2 I was able to capture consecutively bad results using three different testers.
There are many times when I would like to show you results where my line is perfectly stable, but the transferred data speed is crashing from one moment to the next between slow and moderately fast, or when the test is almost at a standstill for 90% of the test only to have the 10% burst cause an unrepresentative result to be reported.
First set of results tonight, while not too bad, are not good either, and are a peak time slowdown on three different tests.
[quote=BTW Performance Test]Download speed achieved during the test was - 5.56 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
Modem has one CRC error in the last 24 hours, and line stats are -
I will test again in half an hour and see if it gets better or worse.
Quote You are currently connected to gateway pcl-ag08
[quote=BTW Performance Test]Download speed achieved during the test was - 5.56 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
Modem has one CRC error in the last 24 hours, and line stats are -
ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 1
Channel: FAST, Upstream rate = 448 Kbps, Downstream rate = 8128 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 11.4 23.0
Attn(dB): 9.0 5.0
Pwr(dBm): 13.8 11.9
Max(Kbps): 9536 1136
Rate (Kbps): 8128 448
I will test again in half an hour and see if it gets better or worse.
Going down !
[quote=BTW Performance Test] Download speedachieved during the test was - 3.16 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
Modem has zero errors since previous test, and stats are now -
Quote You are currently connected to gateway pcl-ag08.
[quote=BTW Performance Test] Download speedachieved during the test was - 3.16 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.13 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7.15 Mbps
Modem has zero errors since previous test, and stats are now -
ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 1
Channel: FAST, Upstream rate = 448 Kbps, Downstream rate = 8128 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 11.5 23.0
Attn(dB): 9.0 5.0
Pwr(dBm): 13.8 11.9
Max(Kbps): 9536 1136
Rate (Kbps): 8128 448