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[grumpy old man]

I have contacted Plusnet over my problem.

They have responded by saying that whilst interleaving could be turned off it is was probably applied to stabilise the line.

It was also suggested that I as I hadn't rebooted router for a few days it should be turned off for 15 minutes and rebooted.  Not sure why this should have any effect, following advice from this forum I leave it on all the time.  Anyway have done as Plusnet asked but as I anticipated it has made no difference to download speeds.

Is the interleaving the possible cause of the lower speeds and if I ask it to be turned off will the line be destabilised and what problems would that cause?

Thanks

gom

[orainsear]

I wouldn't have thought interleaving would be the problem.  Interleaving is simply a form of error correction and unless you are a gamer with a need of better pings is best left switched on.

[Mick]

gom,

ring Metronet/plusnet or PM a member of their team that lurk around in the forums and ask them what your IP profile is.  It may be stuck and they need to reset it.  Failing that they will need to investigate what is wrong because an attenuation as low as yours and a 6500 BRAs profile should get you a healthy 6200-6300 kbps download at off peak times.  They should also switch off interleaving which will give you a small increase in your sync speed and lower latency.  Their explanation that interleaving has been applied to stabilise the line does not stand - unless you have experienced frequent resyncs because of e.g. a storm, or pulling the telephone wire out of the plug.

[grumpy old man]

Mick

Thank you for your response, I will follow up your suggestion.

Interestingly download speed about one hour ago was around 6000 kps, now dropped to 1000 kps.

gom

[Mick]

Looking at the time you posted this, the slow down you mention is most likely due to traffic shaping.

What's it like early in the morning (well before 9)?  If you do get around 6200 kbps, then the problem is with the traffic shaping setup plusnet are applying currently.  In that case, you should ask them to reconfigure their switches as they seem to constrain your speeds somewhat excessively.

Hope this helps,

[grumpy old man]

Mick

Thanks for your further reply.  Have just checked tonight about 15 minutes ago and it was 6800 kps (never achieved this before) now its down to 5700.

I haven't checked first thing in the morning as I normally busy going to work and don't think to check, but will so as suggested.

The fluctuations I am experiencing do seem to suggest traffic problems but living in semi rural location I can't believe the telephone exchange is overloaded.

I haven't had a chance to speak with ISP yet but will raise issue of their traffic shaping.

Many thanks for your continued input on my problem.  It does make it easier being able to discuss the problem with people like your self who understand how ADSL works, and armed with the knowledge to hopefully resolve the problem.

gom

[Mick]

Mick

Thanks for your further reply.  Have just checked tonight about 15 minutes ago and it was 6800 kps (never achieved this before) now its down to 5700.

Right.  All things being equal, this is an indication that there is nothing wrong with your line, but that speeds are throttled.

I haven't checked first thing in the morning as I normally busy going to work and don't think to check, but will so as suggested.

The fluctuations I am experiencing do seem to suggest traffic problems but living in semi rural location I can't believe the telephone exchange is overloaded.

It seems to me that the "traffic problems" you mention are related to the ISP's traffic shaping and the balancing of their gateway switches, rather than your local BT exchange.  Plusnet offer good support (mostly through their forums) and relatively cheap pricing.  However, they are not the ideal ISP if you want fully unthrottled, unconstrained internet connection and you are an advocate of Net Neutrality/Open Internet.  Their business model is similar to cheap holiday flights.  They oversubscribe their service - if you want no traffic shaping then you have to pay more.  However, even on their unconstrained accounts your connection will be routed through their switches and when they do occasionally go out of balance then even people on more expensive accounts suffer slowdowns during peak.

I think that for people who are not bothered if their connection is a few kbps slower during peak times, do not use special (non-common) ports and services and are not concerned about Open Internet principles, Plusnet are one of the better providers available.

Hope this helps.

[kitz]

What concerns me about GOMs low speeds are that he is seeing exceedingly slow speeds on http which should not be affected by any of Plusnets traffic shaping.

As mentioned previously they have been lighting new segments very frequently (on average about 1 a month) and Ive not heard any reports anywhere else of any problems on the PN network that would be affecting GOM's connection in this way.

Ive today checked with several other PN users who all confirm that they are seeing full speed ahead on their connections..  and even no probs on some of the more traditionally shaped things like p2p.

I'm wondering if this could perhaps be some sort of exchange congestion..  I know from my own experiences that my own exchanged didnt go into red, until sub 1Mbps had been recorded.

[Mick]

You're right, it "should not be affected".  However, some times PN do not light up new segments fast enough to cope with demand; some times their switches go out of balance.  I recall that particular gateways almost always dropped more packets than others.

It is true that the http/s packets should not be affected, however there have been times when they were badly throttled on more than one gateways.  There was even a thread a few months ago (I can't find it now but I think it was opened by BarryZ) where he asked for people to provide relevant info like gateway, speedtest results, router stats, etc. in the hope that PN identified some pattern in the problem.

Notwithstanding the above, if as you say the gateways look quiet and other users are not reporting problems, then the slowdown could be due to contention at the local exchange:  GOM, what's your neighbours' ADSL performance like?

[kitz]

Although I seldom have time to follow the community.. I do remember that from last year...  irrc there was some gold packet drop prior to the new 622's being lit?
Did Barry think it may have been affecting the BB+ customers?..  I cant remember the outcome. 
Theres been another 4 or 5 segments lit since then and I cant see any glaring gold packet drops from the network graphs only the expected brown, orange and grey.

Funny enough Barry was actually one of those that I asked today about the network performance and he said that afaik it was fine.


However, this isnt really sorting GOMs slow speeds, could do with one of the PN guys looking at this really to see if they can see anything obvious from their end.
(I'll try prodding one of them).

[grumpy old man]

Hi Kitz and Mick

Thank you both for your replies.  Gets a bit technical at times but think I understand your comments.

I am currently in the process of using plusnets speedchecker over a 24 hour period, for plusnet to then look at my problem.

The results posted are quite interesting:

                          14/03/09   19.10   Actual IP throughout test 124 kbps
                          14/03/09   22.23   5190
                          15/03/09   07.33   5708
                          15/03/09   15.20   4614
                          15/03/09   18.37     186

Following most recent check I have run speedtest.net and got 4380 download?

Mick I can't as you suggest check my neighbours ADSL as neither of them are 'on line'.

I don't really have a problem with slight fluctuations in speed as I don't do alot of downloading, anyway with current infrastructure changes in speeds are inevitable.  However the fluctuations I am getting are clearly not acceptable.

Will post again when I have received a response from plusnet.

Thank you for your continued interest in my problem.  It's great to be able post a problem and get advice from you experts even though I don't always understand the technicalities. 

gom

[jeffbb]

Hi

                           14/03/09   19.10   Actual IP throughout test 124 kbps
                         
                          15/03/09   18.37     186

These 2 fall into the same time band 18:00, 20:00 hrs that PN uses for Traffic shaping . there may be a fault with the way its set up

It might be interesting to try some tests before and after some of the change over times .

see below for details

http://www.kitz.co.uk/isp/plusnet_shaping.htm

Jeff

[kitz]

>> However the fluctuations I am getting are clearly not acceptable.

They certainly arent!!!

 ~ Out of interest which account type are you on? - eg Broadband Plus
 ~ Which router are you using - by any chance is it a Voyager 2100 series?

                        15/03/09   18.37     186

Following most recent check I have run speedtest.net and got 4380 download?

Thats really interesting that PNs own speedtester gives 186 kbps.. yet speedtest.net in the same period gives 4380.
Are you using this one or their older one?

[Jameseh]

Morning guys,

A couple of things from me on this one:

- Interleaving being on or off will have no bearing on extreme peak time slow downs.  If anything, it'll make the line more stable and it seemed to be perfectly stable as it was.

- It's not a traffic management issue.  We prioritise web traffic (which this speedtest will use) so even if we were suffering capacity issues, you should still get decent speed test results.

To me it sounds like one of two things.  It's most likely to be an exchange contention issue, but it could also possibly be MTU/rWin related.  Kitz has mentioned in the past of an issue she's seen on the BT Voyager 210's where they default to an MTU of 1400.

GOM - Would you mind trying to optimise your MTU and rWin settings as per this page?

http://www.plus.net/support/broadband/troubleshooting/rwin_video.shtml

If you'd also like to PM me your username, I'll be more than happy to have a look at your account to see what's been going on.

[Mick]

You just can't top PN support! 

Keep up the good work James.