Impossible speed checks

[#1]

Why does a report on speed problems lead to the rather threatening message

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Broadband Fault Checker - Initial checks [ Completed ] All initial checks have been completed without finding any problems. You now need to visit the Broadband Faults Checker and complete a number of detailed checks to progress your fault further. Please make sure you do this within the next 48 hours, otherwise your Question will close and your fault won't be checked anymore.

The BT speed checker doesn't work you know
What is the target turnround for a problem reported in this way?

[#2]

A target turnaround is probably irrelevant  because people who have speed/line/stability problems, who try to use the fault checker, probably lose the the will to live during the process and give up on it. The question just closes itelf and that is the end of it.

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On what date was your service last fully working?

In terms of a speed problem what does that mean? My service is fully working but slow. So what date do I put?
I put todays date and continued the process until I was asked to do three speed tests etc inc speedtester bt which, as you say, does not work.
Having already been told the exchange is green you get this explanation:

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As broadband is a contended service there may be times when you experience lower connection speeds. BT may not accept a speed fault if speed tests carried out during off-peak times indicate speeds above the minimum acceptable speeds noted below: BT minimum acceptable speeds for broadband service: 100kps or more - acceptable on 512kbps products 200kbs or more - acceptable on 1Mb products 400kbs or more - acceptable on 2Mb, 4Mb & 8Mb products If you have completed at least 3 tests and the speeds returned are above those shown above, we will be unable to progress your fault any further. The cause of your slow speeds are due to contention. Click the Close Fault button

How very useful

[#3]

I hope this is a joke.
I've just reported (well 3 hours ago) a really slow speed - but not so desperately slow as to a gross physical fault.
I'm not doing silly BT speedtests because they always fail (after telling me my profile speed).
I suppose I have to wait a long time, then refer it via these forums to be handled properly.

[#4]

Jeremy,
What is the actual problem you're experiencing?

[#5]

Thanks for your interest, James 
It's ticket ID: 26265511 - but basically:-
Half a BT speedtest (crashing like it does :)) says my profile is 5500Kbps (it was 6500Kbps yesterday)
Plusnet says the same.
My router syncs at 7712 Kbps
But the Plusnet speedtest (and many others) give a speed of 800 - 1,000Kbps.
The effect is very noticeable on web browsing and streaming media is very dodgy.

[#6]

Thanks Jeremy.
Do you know if you are able to configure MTU & rWin on your OS?
I just wonder whether or not you might be able to do a bit of tweaking to bump things up a bit.

[#7]

RWIN (and MTU) is auto-configured (Ubuntu), although I could override them.
MTU is 1500
RWIN is dynamic (min/default/max =  4096 , 87380 , 524288)
I haven't touched these values in months though.
The router is set to 1500.
I notice that RWIN values in a Wireshark dump are mostly quite small though - only around 30,000, but some values are larger.

[#8]

Could you possibly try:
rWin: 111200
MTU: 1430
And then reboot computer and router?  It is a bit of a long shot, but it might help.

[#9]

I've actually got 4 PC's - one of them is Windows XP, running with default MTU, RWIN
3 PC's have static IP addresses and MTU.
The Windows laptop uses DHCP.
The router has had a MTU of 1500 for the last 9-10 months (since I bought it).
They all show the same problem - so I'd rather not change these values, sorry. 

[#10]

I was once told by someone at PN that the <a href="http://www.thinkbroadband.com/speedtest.html">TBB speed checker</a> would be an acceptable alternative to the BT tester, as the results are stored and you can give CS a weblink to them. I have never got the BT tester to work either.

[#11]

Jeremy,
Do me a favour and try my suggested values on the Windows PC?
You probably look at it with great disgust anyway

[#12]

Denzil  - 914Kbps 
James - I'll have a go later tonight on the Windows XP - it's incredibily slow to power up and logon 
I'll try Dr TCP
I must admit I'm not optimistic - I wonder if it's safe to reboot my router or whether BT will penalise me.
I really think that MTU=1500 is OK as:-

jeremy@HECTOR:~$ ping -s 1472 www.bbc.co.uk
PING www.bbc.net.uk (212.58.253.67) 1472(1500) bytes of data.
1480 bytes from www-vip.cwwtf.bbc.co.uk (212.58.253.67): icmp_seq=1 ttl=121 time=74.1 ms

is OK whilst

jeremy@HECTOR:~$ ping -s 1473 www.bbc.co.uk
PING www.bbc.net.uk (212.58.253.67) 1473(1501) bytes of data.

isn't!

[#13]

Quote from: Jameseh

Do me a favour and try my suggested values on the Windows PC? You probably look at it with great disgust anyway

Well, I got a message from my ticket - which said very comprehensively all the things I could do
A major one was to re-boot the router
I suspect that Plusnet must have fixed something - because it's now working 
So thanks are due to Alex T.
He says (in part):-

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Dear xxxxxx, The line tests have completed and are showing your connection to the exchange (known as sync) is set at a high/normal rate for your line. Also all profiling has been checked and is also normal for your account/line. Before all else restarting your router is recommended, especially if you have not done so for a while though only 1 restart is advised as doing so several times can be detrimental to your connection. In general the line test has not been able to find any specific fault with the line, the exchange and copper line itself look fine at this time. As such we would recommend double checking everything at your end that can affect the actual throughput speed of your connection. First of all we recommend that you ensure your equipment is plugged directly into the BT master socket. Try changing the microfilter and modem/router (if possible) as this is a common cause. Filters you may find as they are cheap can be easier to pick up from your nearest PC hardware stockist. Also check for any sources of RF interference that are near the line, this can be anything that can give off an electrical field such as a radio/speakers, any cordless device etc (especially if the fault seems to happen when it gets dark or if a certain electrical devices are on at the time of the fault, even things such as heating can be known to cause problems in some cases). Of critical importance also is that on the software side you check to make sure all is upto date and you are running the latest version of drivers for your modem or firmware for your router. As new technologies progress its more and more essential to keep yourself upto date. Go and research your hardware, A lot of equipment on the market can actually cause problems and you may find a fix for it, check that the makers of the router are not aware of any issues. Also try disconnecting any other devices you have connected to your PC, such as scanners, printers or cameras to make sure they are not interfering. Its also recommended to have your voice line checked by your telephone provider for any faults, any loss of dial tone or noise on the line can cause a severe reduction in speed. Even if you do not generally use the voice service it is important to ensure it is working correctly. PC side its important to ensure when testing that the correct port forwarding is used if using a router to allow traffic to and from the internet to pass correctly, also check firewalls and antivirus are not affecting your connection adversely. A full virus/spyware scan should be done to ensure that nothing is using your connection unknown to you in the background, also at the time of testing make sure all unrequired applications on the pc used to test are closed down and that nothing else is using your connection.

Jamesh - I didn't get as far as changing any MTU or RWIN sizes.
Speedtest is now showing mostly RWIN size of 196912 - I'm thinking that the Linux algorithm previously reduced the RWIN size due to the perceived slow speed previously used.
So RWIN can be a bit of a red herring