There seem to be a fair few complaints going around at the moment whereby users are complaining about poor speeds across all ISPs.

Slow speeds can be attributable to several different factors, but in view of the fact that I haven't seen so many users complain about such poor speeds since the advent of the 1Mb trials, I think its fair to assume that am awful lot of these complaints may be down to exchange congestion - especially after the recent round of BTw bulk upgrades which has left many users with free speed upgrades and eager to use them. :/

However, we should never assume and there are 4 main areas where speed problems can arise:-

1. Your own PC/network.
2. BT's network.
3. Your ISP's network.
4. The remote network.

~ Do a proper speed test. - (Helps eliminate remote network issues).

Do not rely on the likes of p2p transfers or http downloads to monitor your speeds. These are dependant upon too many outside sources to provide an accurate monitor of your connection.

In particular remember that p2p transfers are entirely reliant upon the speed at which the user(s) or server at the other end can send the files to you.

Do not use a foreign speed tester, speed tests that have to traverse the atlantic will always give a slower speed due to the distance involved.

Instead use a UK based speed test on a good server such as the one at adsl-guide or BBMax.

If you have DUMeter or NetMeter its also worthwhile checking download speeds on some test files from the BTOpenworld Server.

~ Check your IP Profile (BTw restriction of your line).

If you are on IPStream DSLMax (up to 8Mb), check your bRAS profile, which limits your maximum throughput speed.

If you have had low sync speeds over the past few days, then your line rate will be adjusted accordingly. It can take 3-4 days of stability before your profile is adjusted back upwards.

You can check your IP profile by carrying out a BTw Performance test.
This will give you an indication of the maximum throughput speed after overheads that your line is likely to achieve.

There's a table which shows relation of sync speed and IP profile bands at the bottom of the page on How dslmax works.

~ Check for Exchange Congestion. - (Helps eliminate BTs Network issues).

Enter your phone number into of the checkers below to see if there are any known problems at your local exchange. (Look at VP capacity).

   Plusnet UserTools Exchange Checker   

Be aware that the exchange checkers rely on information being provided from BTw so therefore they can sometimes be a few weeks behind. - Therefore its also best to carry out a BTw speedtest.
In my own personal experience the exchange checker doesn't go red until speeds below 400kbps are attained on a 2Mb connection.

 

~ Do a BTw Speedtest. - (Eliminates ISP Network and remote network issues)

If you are on IPStream then you can carry out a BTw speed test which completely bypasses your ISP's network and will help identify the area of where the slow speeds are occurring.

Instructions on how to do a BTw Speedtest.

Slow speeds on the BTw speedtester point to either a contention issue at the exchange or a problem on your own equipment/network.

~ Ensure nothing else is using your bandwidth. - (Helps eliminate PC/Local Network issues).

You cannot do a proper speed test if there is an application open on your PC that is using your bandwidth.
Make sure that you don't have any applications open that may be using your connection.
Make sure that no other PC's on your network are using your connection - if possible turn off other PC's whilst performing a speed test.

- Make sure no-one else is using your connection.

If you have a wireless router make sure that you have encryption/wireless security set up properly - Its not unknown for neighbours to be "borrowing your bandwidth".

- Make sure your connection is "clean".

A very common cause of poor speeds is virii, spyware and malware on an infected PC.

Scan the PC for virii using a decent Anti-virus program, also do an online scan such as Housecall.
Scan for spy and malware using both Spybots S+D and Ad-aware.

All these programs can be obtained for free from the links on my page here.

- Monitor your traffic.

Consider downloading and installing NetMeter - this free software will monitor traffic on your PC and you should easily be able to spot if another application is using any bandwidth.

If you feel confident enough you can always try wireshark to capture and analyse any stray packets to help identify the source.

~ Check for packet loss

If you are on a marginal long length line, it's possible to momentarily loose signal which results in packets being dropped. The symptoms of this are that you appear to be getting slow speeds.
Most routers will record the amount of errored data packets, so its worthwhile checking in your modem/router to see if it has recorded any uncorrected CRC errors/Errored seconds. A high count of CRC errors (1,000's) is indicative that you have a problem on your line.
Theses errors indicate that data has been lost and has to be re-requested causing overall slow throughput.

CRC/HEC etc errors can also be a result of interference on the line. A popular culprit around christmas is flashing xmas tree lights.