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Troubleshooting FAQ

My download speeds seem to vary a lot?

As well as testing your connection on the thinkbroadband speedtest and the various other speedtesters that exist, there are two testers run by BT Wholesale, both are accessed by the same gateway web address with the web server redirecting you to the correct test depending on your connection type.

IMPORTANT: These tests are only intended for people with an ADSL connection provided by BT Wholesale. No useful information is returned to people with ISDN or an unbundled connection, and while it will accept your telephone number and ADSL login it does not perform a remote test on your line.

  1. The BT Speedtester is for people on a fixed speed service and uses a special login to access it as shown below:actually will bypass your ISPs own network, and therefore is a good test of your PC/Modem/Line/Exchange.

    To use the speedtester you need to change the login you are using, the username to use is speedtest@speedtest_domain, the password can be anything (click image below for example)

    Then visit the webpage, and enter your telephone number and run the test, an example of the results from a 1Mbps line are shown here. The speedtester will only allow you to run a test every 30 minutes to ensure the system does not become overloaded.
  2. The BT Performance tester at is the one that people with a Max connection will be redirected to. This requires you to enter your telephone number and after this you will be asked for your ADSL login. Since you are using your standard ADSL login the test provides a measure of the download speed across your ADSL line, the exchange, link to the provider and out across the Internet. Once your details have been verified the test is run, and the results displayed as shown below:

    The performance tester is useful for Max users as it tells you your IP Profile, which is the maximum possible download speed you can get from the Internet. This figure varies according to your Max speed, the last line connection speeds as detected by the BT systems are also shown, along with an actual throughput test. A webpage listing the full sequence of screens this tester should produce can be seen here. The performance tester does not bypass your service providers network unlike the original Speedtester.

    Warning: The performance tester sees a lot of traffic at peak times which can result in frustration, currently the testers are quieter from sunrise until around 11am. If using the tester to determine your IP Profile, and it has worked there is no point in running repeat tests. It is worth checking whether your service providers portal displays your IP Profile (sometimes called Data Rate or BRAS Data Rate, alternately the broadband providers support desk may have access to the information.

Due to the way the networks are setup, people with a LLU or Datastream based line will not be able to access these BT test systems.

When uploading, I'm unable to download at full speed?

Due to the nature of the Transmission Control Protocol (TCP), special acknowledgement (ACK) packets must be transmitted back to the source for every packet downloaded (and vice versa when uploading). If you are uploading at maximum speed, these ACK packets will be delayed and take longer to return to the source. The result is reduced throughput on the downstream leg.

Technical users can solve this problem through the use of QoS (Quality of Service) and/or fair queuing. Both of these options may be compiled into the Linux kernel. Products are also starting to appear on the market supporting QoS.

I'm connected but I can't access any websites?

If the router or modem claims you are connected but webpages such as aren't working, try accessing them via their IP address (in this case it's

If this works then you have a DNS problem, most likely the wrong DNS servers are specified. Check which DNS server IP addresses are specified in your computer's TCP/IP network configuration. If you are using a router try adding the actual IP addresses for your ISPs DNS servers. Contact your ISP if you are unaware of these values.

What is Service Selection Barring?

SSB is a system whereby BTwholesale tie your username to a specific line ID. Occassionally the database that holds this information is updated and entries get corrupted or are wrongly added.

When this happens the bt_test@startup_domain login will work, but your ISP's login will not. Contact your service prodvider if this is the case.

bt_test works but my ISP login doesnt?

If it has never worked, check you are entering it correctly and contact your ISP to verify it is correct. Some ISP's have backup dialups, if the same login should work on that - check whether it works - if it fails on the dialup then the login is incorrect or your ISP has a fault.

If the login was working and you've not changed anything, it suggests that either the ISP is having problems with their Radius authentication server - try a dialup backup if it exists - or you've fell victim to Service Selection Barring (SSB).

I have a Fujitsu FDX-310 and my login doesn't work?

Verify the number that is entered in the 'telephone number' part of the Windows Dial Up Networking connection you are using. For the UK with a BT phone line it should be '0,38' - if you are on the Karoo service it is '0,50'.

My router won't login!

Check that the router is detecting an ADSL signal. If you have an ADSL signal but you're unable to login, double check the VPI/VCI values - for BT based products (most cases) they should be VPI=0, VCI=38. For Karoo the values are VPI=1, VCI=50.

My ADSL hardware is not synchronising?

The first stage of installing ADSL is getting the ADSL modem to sync to the local exchange, until this happens you can't login.

There are several things to try:

  1. Check all the leads are in the correct places
  2. Remove all the phones and other telephone equipment from the line and check again.
  3. Remove any micro-filters.
  4. Try the modem at the master socket, you can also unscrew this faceplate and use the internal phone socket which should bypass any alarm/extensions you have.
  5. Check the ADSL mode the modem is using, try in the following order Auto, DMT, ANSI
  6. If possible try the modem on an ADSL line that is known to work, or borrow a known working modem.

At end of the day if you have proven the hardware to work elsewhere and ruled out your wiring, it's probably best to report the problem to your ISP or assume your line hasn't been activated yet.

I have an Alcatel/Thomson Speed Touch USB modem but I can't login?

If the USB and ADSL LED's are both solid green, but both bt_test@startup_domain and your ISP login refuses to work and has never worked then you may have been supplied the wrong driver CD.

To check this bring up the Alcatel diagnostics program, i.e. the small stingray icon in the system tray and compare it to this. Specifically your VPI and VCI should be 0 and 38 respectively if not do the following:

  1. Unplug the modem and uninstall existing drivers
  2. Download new drivers from the support section of the UK speedtouch site and install
  3. You should be able to plug the modem back in and obtain a connection.

Windows claims there is no dial tone?

This happens with the modems that use Windows Dialup Networking (DUN), it's not referring to a normal phone dialtone when using ADSL, but rather the lack of ADSL signal. Check your ADSL modem, they generally have an ADSL or Link light which should indicate whether or not an ADSL signal is present.


  1. If it's a wires-only install and the activation date hasn't passed yet, this is normal, once your ADSL light goes solid green the line should work.
  2. If your activation date has passed and you still get this message, check your wiring and use of micro-filters (splitters). Try unplugging all telephones and running the modem from the master socket. Do remember that Sky and Sky+ boxes count as a telephone, since they have built in dial-up modems, and therefore must be filtered.
  3. If the connection has been previously working, check everything is plugged in correctly and then contact your ISP.

What is the bt_test login?

A generic login exists that will work even if your ISP login refuses to work, or your ISP is offline. Also if you are experiencing intermittent problems with your connection, it's good to check with this test login, the login bypasses your ISP totally.

The login is:
Username = bt_test@startup_domain
Password = (ignored)

Once authenticated, you can browse to a single site, "" which currently consists of a single graphic image.

For people with static IP's or NON-NAT setups, depending on how you've configured your ADSL modem you may need to change other settings to browse to the website. Users with USB and PCI modems should have no problems.

NOTE: The bt_test login will not work on services that are provisioned using the BT Datastream wholesale products.

What is the purpose of this FAQ?

This FAQ lists both generic and specific problems that occur during the first couple of days after attempting to your get your self-install or engineer-assisted connection working. As questions and solutions pop up in the forums they will be moved over to here for reference by other people.