ADSL in the UK

 

This page was written by Christopher Spry. On 1 November 2000, BT installed a 'Universal Serial Bus' (USB) 'Asymmetric Digital Subscriber Line' (ADSL) service for me through the Wimbledon exchange in South West London. As this was a new commercial service, starting in June 2000, I have collected information about USB ADSL, which may be of interest to others. Because my experience is limited to use of the BT 'Openworld Home 500' USB version of ADSL under 'Windows 2000 Professional', specific comments below refer to that service. 

Please send me corrections and suggestions for updates.

I acknowledge the many people at news:uk.telecom.broadband who have provided the information on which this page is based.

Index

• 1.  The basics of ADSL
• 2.  Requirements for USB ADSL services
• 3.  ADSL providers in the U.K.
• 4.  Installing the ADSL USB driver on the host PC
• 5.  The work done by the BT engineer at your premises
• 6.  Checking that the router and service are set up correctly before the engineer leaves
• 7.  Setting up an Internet Service Provider (ISP)
• 8.  Connecting to the ADSL service at startup or login
• 9.  Known problems with UK ADSL
• 10. After setting up an ADSL connection
• 11. Dynamic and static IP addresses
• 12. Security
• 13. Networking other local computers to an ADSL connection: ICS
• 14. Networking local and remote computers through an ADSL connection: VPN
• 15. Support and what to do if the service stops working
• 16. 'Business Plus' services with a fixed IP address
• 17. Alternative routers to the standard Alcatel USB router
• 18. Planned improvements and updates of BT's ADSL services

1. The basics of ADSL

ADSL is the latest communications technology to enable computers to connect to each other over Internet using a standard copper telephone line. It is a replacement for dialup modems and ISDN. The ADSL 'signal' is carried by two ADSL routers, which look like modems. (ADSL routers are sometimes incorrectly referred to as 'modems'). ADSL routers send IP packets through the copper wire that links your phone to the local telephone exchange, which has to be less than about 5 km away, to ensure there is no significant signal loss. The line is tested to ensure that it will support ADSL before it is installed. One of the ADSL routers is provided in your premises and the other is in the local telephone exchange. A 'splitter', or 'filter', at each end of the line, separates voice and ADSL signals, so that phone calls can be made at the same time as the ADSL link is being used. 

The main advantage of ADSL is that the connection appears to be always 'on', so there is no wait to get connected to Internet, it is much faster than ISDN (about 50 KB/sec) and there are no call charges: the charges include an installation charge, then a fixed fee for a set period: month, quarter or year.

There are two types of ADSL router. One type has an ethernet (RJ45) connector on it, which is used by more expensive services, because it is designed so that several computers on a local network can use the service directly through the router. The other type of router has a USB connector, which provides the cheaper (domestic) services. The USB version of the router is designed to be used by just one computer, although several computers on a local network can be set up to use the service via the computer attached to the router.

Routers at the end of each line must be using the same DSLAM protocol, which will be either 'PPPoE (naturally ethernet)' or ' PPPoA (ATM)'. BT's 'Home 500' service uses PPPoA. Each type of modem can use either protocol. The service provider decides which one to use. It makes no difference to the user which protocol is run.

• ADSL routers, that have RJ45 connections, are provided with a 'static' or fixed and registered IP address. In this way, the local network can be an Internet web server and provide e-mail, ftp and other functions to and from other computers on Internet. Clearly, this type of network must have security, such as a firewall, in place. Other ADSL connections using RJ45 connectors, where higher security is needed, are just provided with a single, real, RIPE registered, IP address and the other computers attached to the ADSL router are given private network IP addresses in the reserved range '10.x.x.x', which is not visible from other networks. The reserved IP addresses are either set manually on each PC, or via DHCP. The PCs use these IP addresses to communicate with each other on the local network and with the ADSL router, using a protocol called 'network address translation' (NAT). Perhaps the main benefit of ' NAT' connections is that an external hacker can not connect directly to PCs on the private network and cause problems. This is because the local computers cannot be accessed directly by computers elsewhere on Internet, which can only 'see' the IP address of the ADSL router. But note that NAT is not resilient to all types of attack, so extra security is still recommended. 
• ADSL routers, that have USB connections, are provided with a 'dynamic' (variable) IP addresses. This type of connection is the cheapest to setup and run. More customers are allocated to each segment of the network than other the first type of ADSL connection described above. The 'USB' router can only connect to a USB port on a single computer. This computer must be running Windows 98, Millennium (ME), Windows 2000 Professional, Windows 2000 Server or Windows XP, because other Windows operating systems do not support the USB port. Computers running Linux can be setup to use ADSL routers - see below. Other computers on a local network can run any of the Windows operating systems, as they use the service via the computer attached to the USB router. The 'USB' version of the ADSL router is not 'NAT-enabled' and no ports are blocked. 

In practice, there is little difference between RJ45 and USB ADSL connections, because networked computers can also use the ADSL USB resource on the connected PC, if they run connection software that include Windows 'Internet Connection Sharing'. The main difference is that connections from Internet to the USB-connected computers are usually designed to run slower and they are not designed to run a web and other Internet services from the local computer. They may have slower transmission speeds at peak times, because more people share a line, i.e. have a higher 'contention ratio'. Some potential uses of ADSL, such as web hosting, are not allowed in some service contracts for USB ADSL connections, so it is worth checking details before deciding which service provider and which service to install. If you need them, upgrade to services using routers with RJ45 connectors and fixed IP addresses.

See also:

• There is a UK ADSL 'FAQ' at 'multithread.co.uk'.
• SEG Communications have an excellent overview on ADSL and a comparison with ISDN.
• 'ADSLGuide.org.uk', which is hosted in Canada, but has a wide range of information about ADSL in the U.K. and 'ADSLuk', which has more limited information.
• Broadband advice including Security.
• Proxy server issues.
• Links to broadband access and content.
• DSL in the USA with some useful information for UK users.
• Satellite ADSL services are becoming available in the UK, including BT's Openworld Satellite.

2. Requirements for the USB ADSL services 

• You must have a BT PSTN (standard) phone line connected to the place where the ADSL service will be used.
• If your telephone line is a 'Digital Access Carrier System' (DACS) or shared line, it can not be used for ADSL. To check if you have a DACS line, follow the phone line out the window until it reaches a black and/or grey box. If the line is 'DACS', the grey box will usually have a DACS or DACS 2 label on it. If you find you are on one of those lines, arrange for BT to convert it to a single user line before installing ADSL. Note that DACS boxes are sometimes in places where you can not check them yourself: on top of poles, under the ground or in BT's PCP's. Then, you will have to phone BT to find out if you have one. 
• Check that your local UK telephone exchange can provide ADSL services.
• Check that your UK phone line is close enough to the exchange to allow it to use ADSL. To do this, dial 17070, then select option 3, option 1 and option 2. The answer will tell you how far you are from the exchange. If you are more than about 3.5-km, ADSL will probably not be able to work properly. BT will carry out a definitive ADSL test on the line before and after installing it. This is called the 'whoosh test' and is carried out through 'BTIgnite', which is the part of BT that installs the hardware in the phone exchanges. It is separate from BT Openworld. The line distance measurement can only be used as a guide to whether the service can be used or not. The definitive test involves measurements of line capacitance in 'nanofarads'. Capacitance acts as a filter, allowing certain frequencies to pass and blocking others. In the case of telephone wires, which were not designed for ADSL use, a high capacitance level can prevent the frequencies used by ADSL from being transmitted properly. Capacitance is affected by cable length, insulation, moisture etc. Line 'noise', which is measure in dB on a logarithmic scale and as a signal/noise ratio, is unrelated to capacitance, which is the important function being tested. The capacitance on my phone line was 7 nanofarads, which is very good. BT engineers will usually accept a capacitance up to about 47 nanofarads as adequate for ADSL. 
• If the line is noisy or it fails the BT line test for ADSL, ask BT, phone 151, to 'lower the gain' on the phone line, if it is in the high position. This can enable a line that fails the line test, to become useable. 
• If you have a PC, it must have a USB port to connect to the USB modem for the home USB service. Business users will need to have a network card to connect to the RJ45 connector on the modem.
• Your PC must have a USB port that can provide a constant 500mA of power for the router. In addition, some USB cards can not do so, including the 2 Port USB CMD Chipset Bus Port PCI Card. A USB card that does work is provided by Belkin. Check that it is DSL-compatible before you purchase.
• You will need to have a CD-ROM drive to install the Alcatel USB router driver, which is sent to you on a CD in the 'Welcome Pack'. Alternatively you can downloading the driver and install install it from your hard disk.
• If you wish to connect the PC on a USB ADSL line to other computers on a local network, it will have to have a network card set aside for this function. 
• The computer to be used for an USB ADSL connection is usually running Microsoft Windows 98, Millennium (ME), Windows 2000 Professional, Windows 2000 Server or Windows XP, which support the USB port.
• It is also possible to use Linux on the computer connected with a Linux driver for the Alcatel ADSL router. It is necessary to use a version of Linux that has kernel v 2.2 and later, that supports USB. These include the SuSE, Mandrake and Debian distributions of Linux. There is a page of useful links.
• An ISDN line upgrade to ADSL can now be ordered online or by phoning 0800- 169 6922, Monday to Saturday 08:00-22:00. All orders are subject to a line test and to the customer already being connected to an ADSL-enabled exchange. The upgrade currently supports ISDN2, ISDN2e, Business Highway and Home Highway users.
  Previously, if you were running BT's HomeHighway or BusinessHighway (ISDN) service, it had to be disconnected by BT and the line converted to a PSTN (standard) phone line, before the line could be used for ADSL services. This could take some time and it was done by a different group in BT from those who install ADSL. For these reasons, it was often best to install ADSL on a separate line and to keep the ISDN connection working until the ADSL service was fully operational, then to ask BT to terminate the ISDN line, which has no disconnection fee after the first year of use with HomeHighway and two years with BusinessHighway. 

3. ADSL providers in the U.K.

There is a list of ADSL providers at 'ISP Review'. A comparative table of over 39 ADSL providers is available from NetConnex Ltd. All of them use the ADSL hardware provided by BT's division called 'BTIgnite' in BT exchanges. All ADSL Internet Service Providers, including BTOpenworld, are supposed to be treated equally by 'BTIgnite', when setting up ADSL services for customers. On 13 December 2000 Telewest, NTL, Global Crossing, Worldcom and KPNQwest scrapping their earlier plans to provide DSL services, in view of the high cost of setting up the networks to support it.

• Andrews & Arnold Ltd.  with ADSL information, telephone: 0118-376 0000. They provide 500/250 USB ADSL, with any number of IP addresses (subject to RIPE rules) and delegation with no bandwidth limitations for £76.37/month for new connections. They also provide RJ45 connections as well as USB.
• BT's 'Openworld'. This is the service that was installed for me when I signed up. BT have telephone access at 0800-917 9189 for Sales & Support, 0800-169 6922 for Orders and 0800-169 8639 for Registration.
  • The Openworld 'home 500' service provides download speeds of about 50 Kilobytes per second (about nine times faster than a 56K modem) and uplink speeds of up to 25 KB/s, with a contention ration of 50:1 or less. This is for a USB router service, with no port blocking and variable IP address. It costs £150 to install and £39.99/month rental, including VAT. BT's 'Terms and conditions' specify correct use of their connections and the importance of contact names and addresses on web sites.
  • The business service provides an RJ45 port on the router and has a fixed IP address.
• Claranet offer a fixed IP address and no port blocking.
• Demon Internet with ADSL Information, telephone: 0800-027 0563.
• EasyNet. There are reviews of the service.
• Firstnet telephone: 0113-294 4224.
• Nildram with ADSL Information, telephone: 0800-496 2909. The can supply a service with a static IP address.
• PlusNET has a good website and comparisons of prices with other providers.
• Zen Internet  can provide ADSL with a fixed IP address.

Late delivery by BT, who do most of the installation work, is a problem for some ISPs, so confirm planned installation dates before making a firm commitment.

BT also provide a video on demand (VOD) service called 'HomeChoice', which uses ADSL to transmit videos to television sets. Part of the ADSL bandwidth is available for computer users to access Internet. The service was designed to be an alternative to Sky Digital and other digital video and TV service providers. I have not used the service, but I have read that the TV picture quality is, unfortunately, visibly lower than other digital TV services. The main problem for computer users appears to be that the allocation of bandwidth on the HomeChoice ADSL line between the Internet service and the TV service is fixed. This means that you may only get speeds of up to about 10 KB/s to Internet with HomeChoice, whereas dedicated ADSL connections regularly provide 50 KB/s.

4. Installing the ADSL USB driver on the host PC

BT usually provide a 'Welcome Pack' with information about the service, with your account number, 'logon gateway username' and a 'logon password' (PIN number), before an engineer is sent to install the connection box and USB router at your site. If you do not receive it, phone BT's Order Management 0800-917 9189 several days before the engineer is booked to visit, and ask them to send it. The 'Welcome Pack'  should contain a CD containing the latest approved Alcatel USB ADSL driver software for the router. Alternatively, the engineer may bring the CD with him. You can download from 'BT Openworld' and install the latest BT-approved Alcatel USB router driver software (Alcatel USB DSL driver version 1.4, May 2002). Note that, if you have the early and faulty 'BT version ab04' Alcatel driver, you should replace it with the latest driver. The newer Alcatel Speed Touch USB driver still under test is version 1.60 beta (May 2002). This driver should only be used when other drivers are not working.

The engineer is not allowed by BT to install the Alcatel USB ADSL driver software on your own computer or check that your computer is able to use the service. His function is simply to wire the router to the splitter box in your premises, attach it to the router, switch it on and check that his portable computer is able to view a BT diagnostic web page using the router. 

 It is highly recommended that you install the Alcatel USB ADSL driver software on your own computer before the engineer comes or while he is working on your phone line. If you do this, you will be able to test the line before he leaves. The router should not be connected, while the driver is being installed. To install the driver from the CD, insert the CD into the CD-ROM drive on your computer and follow the instructions on-screen. Otherwise, use the downloaded driver to install the software. Once the software is installed, reboot the computer. Then attach the USB router and it will be 'recognized' automatically and installed as a device, which is visible in 'Device Manager' under 'Modems'.

If you are using Windows XP, use the 1.3 version drivers included on the CD-ROM supplied with the Alcatel USB router. Do not use the later version 1.4 drivers, as they may cause problems under Windows XP. To install the Alcatel router under Windows XP, do not preload the drivers but simply plug the modem in and when the 'Found new hardware' wizard starts, let it install automatically the drivers present on the supplied CD-ROM.

5. The work done by the BT engineer at your premises

ADSL connections are organized by BT's 'ADSL provisioning', who notify an 'Engineers Manager' to send an engineer to install the service. The engineer will take 20 minutes or more to install the splitter box and router at your site. He will extend your incoming phone line close to where you will be using the computer and attach an ADSL 'splitter' box to the wall. This box has two sockets: One is for a standard telephone handset. The other socket has a 2-m cable that connects the splitter socket to the Alcatel ADSL modem, which sits beside the computer. The USB router does not require an electrical outlet for power which is taken from the computer's USB port. 

When the router is powered up, green lights at the front confirm that the router is switched on and can 'sync' with the external line, but there are no lights to show whether it has been configured properly. A blinking green light shows that a connection is being negotiated. A persistent blinking green light indicates a problem in the connection between the router and the exchange.

The engineer will use a BT portable computer to connect to the router and check that the ADSL line is working. He logs in to a reserved ADSL BT site as startup_user@startup_domain with no password. If this fails, he may phone BT's Broadband Operations Unit (BOU) and ask them to check that they can 'see' your router and, if necessary, download configuration data into the router. He will persist until he can connect his portable computer to the BT web site. However, as this site is not on Internet, his connection is no guarantee that Internet services will work for you. He cannot test Internet connections through the DSL line, as his portable computer is configured to only access the BT site.  As the engineer is not able to check that the ADSL service is working properly with your computer, you would be wise not let him go until you have checked the service yourself.

It is highly recommended that you check that the ADSL service works, before the engineer leaves your premises. Otherwise you may be faced with many frustrating phone calls to BT. These are seldom answered in less than 30 minutes and you may only be able to talk to an operator who will relay your messages. Users are reporting that non-functioning connection can take days or weeks to fix. BT do not guarantee that the line will function from any specific date. 

6. Checking that the router and service are set up correctly before the engineer leaves

Here are some of the things that you can do to test the service quickly, while the engineer is tidying up or having a mug of tea.: 

First, connect the cable from the router to the USB port on your computer after installing the USB driver. It will install automatically.

Then setup a 'Network and Dial-up Connection' to your Internet Service Provider, which was 'BT Openworld' in my case. Use the 'USB router' as the device, put a space in the phone number box and the TCP/IP settings must be set to obtain an 'IP address automatically' and 'DNS servers automatically'. (If you have a router with an RJ45 connector, which provides a static IP address, the 'Network and Dial-up Connection' to your Internet Service Provider will have to show the IP address for your router. BTOpenworld DNS servers have IP addresses 213.120.62.97 to 104). 'Dial' using this connection and enter your 'logon gateway username' and 'logon password' there and hope that you will connect to the ADSL service. The 'logon gateway username' will be of the form of email/username@hgx.btinternet.com (for example jbloggs@hg3.btinternet.com). Both are usually provided in the 'Welcome Pack'. I f you do not know what they are, or you suspect that they are different from what you were sent, phone BT 0845-600 7020 to ask for them. If you see the error message 'Error 650. Unable to contact remote server', the service is not connecting in the exchange. If you suspect that this is because BT's gateway computers are malfunctioning, attempt to deal with this as described below under 'Home Gateway'. If this does not work, request the ADSL engineer to telephone BOU to check that the router is visible at their end and if necessary to configure it correctly. Persist until the router is shown to be functioning properly and you can connect and use Internet. Some users have reported that there are malfunctioning routers, so it would be sensible to ask the engineer to try another router, if you are unable to make a connection. If you suspect that the problem is with your username/password entry, try to log in with the 'test' username: startup_user@startup_domain with no password, and see if that works. 

If you have a router with an RJ45 connector, which provides a static IP address, try to 'ping' this address from the computer. If this fails, the router is not working and it should be replaced. Now ping the NAT address 192.168.254.254 to see if it is visible on the local network. 

7. Setting up an Internet Service Provider (ISP)

The organization that contracts to provide your ADSL service is your ISP. They will provide details of their services. It is not always necessary to install their software that alters your web browser in a way that shows that you are using their service. You will be using their services as soon as your computer is connected to ADSL, because your connection is routed automatically to their servers. There will be email, Usenet and other resources which are specific for each ISP provider. In the case of BT Openworld, you only need to install the Alcatel modem driver, as described above, and have an ADSL connection, to use 'Openworld'. The 'Openworld' POP3 and SMTP servers are both called 'mail.btinternet.com' and the Usenet news server is 'news.btinternet.com'.  Business users with the RJ45 modem and 'OpenWorld', will be connected to the 'BTClick' email, news servers and web servers, whereas home users with the USB modem who install 'OpenWorld', will be given access to the 'BTInternet' servers which provide the same services as 'BTClick'. Users can have up to 10 email accounts. Users' web site have the URL http://www.username.btinternet.co.uk/.  A telephone dialup account is automatically made available at 0845-756 0000 for users who have a BTOpenworld account. Login using 'username@btinternet.com' and password.
 

8. Connecting to the ADSL service at startup or login

If you wish to connect automatically to ADSL each time that you startup your computer or login, you can either:

• Place a shortcut to a web page in the 'Startup' folder and set the default 'Dial-up Networking' setting to 'connect automatically'.
• Under 'Windows 2000 Professional' you can start up the connection on a command line by running 'rasdial connection_name username password'. Then you can store this in a .cmd file and put a shortcut to it in your startup group.
• It is possible to make this 'rasdial' command a 'service', to load automatically when the computer boots.
• In Windows 2000, set rasdial.exe to start the connection as a Group Policy at login, as recommended by an anonymous correspondent: 1. Start Microsoft Management Console (MMC) by clicking Start, clicking Run then typing 'mmc'. 2. On the Console menu, click Add/Remove Snap-in. 3. Click Add, click Group Policy, and then click Add. 4. Click the appropriate Group Policy Object (the default selection is the local computer). Note that you can click 'Browse' to select a different Group Policy Object. 5. Click Finish, click Close then click OK. 6. In the Group Policy Management console, locate the following folder: 'User Configuration\Windows Settings\Scripts (Logon/Logoff)'. Note that you can substitute the Computer Configuration folder for the User Configuration folder. 7. Double-click the Logon script object. Click Add, click Browse then click the c:\winnt\system32\rasdial.exe. 8. After you select rasdial.exe, click Open, and then click OK. 9. Add <connection name> <username> <password> as the options. 10.Click OK, and then close the Group Policy Management console.

In Windows NT and Windows 2000, you can logout as a user, but retain your ADSL connection, as explained at Microsoft and Jsinc.com: "082 » Keep your RAS connection when you logoff Windows NT/2000, edit: HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon
and add the value KeepRasConnections as a type REG_SZ. Set it to 1"

9. Known problems with UK ADSL

• Error messages using the Alcatel modem driver v 1.2.2: (This section is incomplete)
  • Error 645. There may be a fault in the router in the exchange.
  • Error 650 = "The Remote Access server is not responding."  This has several causes. Check that you are entering the correct 'logon gateway username' (for example jbloggs@hg3.btinternet.com) and 'logon password'. Then disconnect the router from the computer, power down, switch off, plug the router back in again, then reboot. If the error persists phone BT support at 0845-600 7020 option 2.
  • Error 721 = "Remote PPP peer is not responding.". This is usually caused by a failure at the gateway computer. You may be able to get round the problem as described above.
• There are occasional periods when the BT ADSL service fails. If you suspect this, phone 0800-169 0199 and there may be a recorded message. If there is not, there are probably no known problems with BT's service. Do not wait to speak to a support engineer, as this can take up to 40 minutes.
• Occasionally your ADSL router is given a 'reserved' IP address by the BT Openworld's DHCP server, in the range '192.168.x.x'. This can happen when the server runs out of IP addresses. Unfortunately IP addresses in this range are 'non-routable' (e.g. do not work). You can check if this has happened by opening a DOS shell on the computer that is connected to the ADSL router and typing 'ipconfig'. The 'gateway' IP address is the one to check. You have to wait until BT has fixed the problem, so try to connect again later. Note that all other computers sharing the ADSL resource with 'Internet Connection Sharing' are usually given an IP address in the '192.168.x.x' range, which is normal and indeed required for ICS Client computers. BT request that you report  the  '192.168.x.x' problem by email to ip.problems@btinternet.com, including the 'session'; IP address given; your login (network) username (i.e. a.user@hg1.btinternet.com) and the telephone number that you had ADSL installed on. 
• The Alcatel USB ADSL driver called 'BT version ab04', which was installed in some BT Openworld 'Home 500' and 'Business 500' sites, does not work. It should be replaced.
• Home users are connected to Internet through BT's 'Home Gateway' (HG1, HG2...HG9 etc.) servers, which have periods when they may fail. It is possible to change from HG1 to other gateways such as HG2, HG3 or HG4 ... etc, to get round the problem. Disconnect from ADSL, then go to reconnect and when the 'Dial Up' window opens, click on the 'Settings' button and then where you type in your username i.e. xyz@hg1.btinternet.com you simply change the 1 to a 2, for example. Click 'OK' and then try to connect again, this time to a different gateway. However, from early March 2001, the ability to connect via any Home Gateway other than the designated one will be phased out by BT.
• Computers with two processors (CPUs) may crash intermittently, or fail to work properly, using the BT ADSL service and the Alcatel USB modem driver v 1.2.2, which is the latest. There are two possible ways to deal with this, as a temporary step before Alcatel and BT issue a fix
  (a) If you are using Windows 2000 Professional, edit the 'boot.ini' file in the root directory. At the end of the line ending in '/fastdetect' add a space then ' /onecpu', without the apostrophe. If this change does not work, it may be necessary to change from using a multiprocessor 'hal' to a uniprocessor 'hal'. To do this, right click on 'Computer' in 'Device Manager' and bring up 'Properties'. Click 'Update driver' and prompt for a list of known drivers. Select all the devices in the hardware category and you should see several system (HAL) types. If you are using MPS ACPI HAL, you need 'Uniprocessor ACPI HAL'. If you are using the standard 'MPS HAL', you need the standard 'Uniprocessor HAL'. 
  (b) An alternative suggestion to make the crashes less frequent, is to turn off power-saving for the USB device in Device Manager.
• PCs running Norton 'Firewall 2001' and Norton 'Internet Security (NIS) 2001' with the Alcatel USB modem software, may force a reboot occasionally, when viewing web pages. When the 'automatically reboot' setting in 'startup and recovery' is disabled in the system settings, this error causes a crash with a 'blue screen of death' instead, requiring a manual restart. Symantec have been aware of this problem for about 6 months now, but have not provided a fix so far (6 January 2001), although it is possible that the problem is with the Alcatel driver. If you have this problem, install different firewall software
• The current router drivers do not support resumption of ADSL services after a connected computer has been put into 'Suspend' or Hibernate' mode. The computer has to be rebooted before ADSL services can be used again. After hibernation, 'Windows 2000' issues a global reset and then a port reset to the USB controller. If the port reset is not successful, the USB controller becomes unresponsive to commands. This behaviour is most likely to occur if the motherboard uses the 440BX/443BX chipset with the PIIX4(E) chipset. A Microsoft article implies that Microsoft has extended the functionality of uhcd.sys to accommodate the PIIX4(E) chipset and directs you to phone Microsoft Product Support Services for this hotfix. ICS Client computers can enter 'Suspend' or 'Hibernate' and then use the ICS Host computer which connects them to Internet. This problem may be fixed by installing the new router driver v 1.3.
• Computers running 'Windows ME' may crash when closing down. This appears to be due to a conflict between Windows ME 'vxd requests' and the Alcatel 'ndiswan' drivers. If you are competent in altering networking functions and do not use 'ndis' services for any other purpose, try disabling the default 'ndis' and 'ndiswan' vxd's, through the system configuration utility. Alternatively, disconnect from ADSL before closing down. This problem may be fixed by installing the new router driver v 1.3.
• Most UK ISPs provide ADSL to commercial customers (IPSs) using 'IPStream' but BT are only beginning to provide ISPs with Service Level Agreements (SLA), detailing the acceptable level of service that BT will provide. This means that ADSL services through IPSs may be of variable quality and consistency until their service agreements have been put in place.
• Some telephone exchanges appear unable to cope with ADSL, even though they have been set up to use it. This is known as the 'capacity' constraint. It prevents some users from making connections, even though their installation has been done correctly. BT say that they will provide “additional capacity”, to deal with this problem. Some users have been waiting for 4 weeks.
• Some USB routers draw 500mA through the USB port. Not all USB ports can sustain this current. The effect is sudden loss of a connection when the router suddenly stops working, requiring the computer to be restarted. UBSMan has a list of cards that do work with ADSL. Bob Crabtree emailed me that 'My problems [with USB] disappeared the day I switched off the onboard USB on my VIA-chipset PC and put in an ADS-branded four-port USB PCI card that use Lucent chips and delivers all the power the modem needs. A friend had the same problem with a much newer PC, based on an Abit K7 Raid motherboard (again VIA chipset), and his problems were also cured by using the same model of ADS USB card. We are carrying a review in the Feb issue [of 'Computer Video'] telling the story of how the ADS card affected a cure'. The Opti USB PCI board, which can be bought from Dabs  for about £30, works well with the Alcatel router. One of the cheapest separately-powered 4 port hubs can be bought from Sherwoods for £29.90 including VAT. 
• When you use the Windows 2000 'Internet Connection Sharing' (ICS) service to connect to a modem pool, the router might not respond or might respond incorrectly by not dialing or dialing only in pulse mode. An incompatibility between the Modem Sharing client and the standard Unimodem driver causes the client to send a corrupted initialization string to the router. A Microsoft article describes this problem and directs you to phone Microsoft Product Support Services for the hotfix, which us a new version of 'modem.sys', released on 17/05/2000 but not fully regression tested.
• During the first year of operation, BT Openworld setup a 'transparent' web proxy for HTTP traffic through port 80 on their networks. On 5 October 2001, they announced that it was removed, after pressure from users. They had complained that it could cause out-of-date pages to be shown and prevent some web sites, such as http://groups.google.com/ from being viewed. When the 'transparent' proxy serve was used, there were several ways that users could view web sites that were apparently unavailable:
  • 1. If you are using BT's OpenWorld ADSL, you can specify, in your web browser, another  proxy server called 'www.cache.btinternet.com', using port 80 or 8080. A proxy under test is 'in-eval-proxy.btopenworld.com' using port 3128.
  • 2. You can setup one of the many free proxy client computers on a port other than 80, in your browser, for example 'webcache.dial.pipex.com' using port 3128.
  • 3. You can request an 'inaccessible' web page by entering its URL into a Safeweb window.
  • 4. You can add '?a=1' to the end of the URL. e.g. http://www.microsoft.com/ms.htm?a=1. This will make the proxy think that you have sent some information to the web server and it will force the server to send you a fresh page.
  Note that, if a web page author wishes a page to have a lifetime of five minutes before a transparent cache checks for new content, then the http header for the page should contain the following control: 'Cache-Control: max-age=300'. Alternatively, if the author would like their web pages not to be cached by a transparent cache at all, the http header should contain the following control: 'Cache-Control: no-cache'.
• BT Openworld does not provide reverse DNS functions. Web sites that require this, will not function properly. This has prevented me from updating one of my webs on Internet, using 'FrontPage 2000'. There is no solution to this, other than publishing the web through another dialup connection, that does support reverse DNS lookup.
• If you find that the ADSL connection is 'dropped' after about 20 minutes, check the dialup setting: In Windows 2000, right-click on the Internet Explorer icon, select 'Properties | Connections'. Highlight the ADSL internet dialup connection, click 'Settings | Advanced' and ensure that the 'Disconnect if Idle... ' check box is not active.
• Some BT ADSL connections used for internet games have problems with 'lag', 'latency' or 'ping spikes'. If this affects your connection, BT have requested that you email latency.temp@btinternet.com with your login (network) username (ie: a.user@hg1.btinternet.com), the telephone number that you have had ADSL installed on and any other relevant information to help them resolve the problem. There is information and advice at the Openworld On-Line Gamers Usenet resource called btopenworld.broadband.gamers.chat.
• There have been reports that the Alcatel router can fail, after working correctly for several weeks. If it fails, One sign that a replacement is needed, is when Windows fails to start with the router attached. During the boot routine, both router lights may first go on for 3-4 seconds then go out and finally flash red for a moment. The router failure can be confirmed by booting Windows without the router attached. When the device is connected, although new hardware is found, the computer locks and has to be restarted. The resolution is to ask BT to supply a replacement Alcatel router.
• If the computer sometimes fails to start with the router attached, check to see if the symptoms suggest that it is the 'Registry Corruption Bug'.

10. After setting up an ADSL connection

• You are likely to be provided with the Alcatel ADSL modem drivers on a CD. As they are still in development, check to see if there are updated drivers. 
• Once your ADSL modem is connected, you can measure the 'speed' of a connection online from your computer to a server at 'Computing Central', Redmond, Washington USA. This site also indicates and accounts for the connection speeds that can be expected for a variety of connections. DSLReports gives a choice of two servers on the west and east coast of the USA and measures speeds up to 2 megabits/second (Mbps). Note bits/second 'bps' are different from bytes/second 'Bps' because one 'byte' contain several 'bits'. If you consistently find that your 512 ADSL connection, which should run at about 50 KB/s, is running at 10 KB/s or less, carry out this fix. A 'Broadband Internet Speed test program' has been provided by Danny Elwell, including an executable to test BT's Openworld connections. It requires an additional file called sysfile.exe. The program measures the ping times to servers in the UK and worldwide, the average download speeds, packet loss and routes to problematic servers and it is not restricted to using just one server. A report is generated which can be send to an ISP to help define possible download problems.
• You can install Microsoft's 'Internet Connection Sharing' so that other computers on a local network can use the ADSL USB modem. I have a guide on how to do this.
• Install a firewall and check the security of your connection. 

11. Dynamic and fixed IP addresses

The cheaper 'Home' or 'USB' ADSL services provide a 'dynamic' IP address, which may alter each time that a connection is made to the ADSL service. In April 2001, BT altered the way that they configured DHCP, so that a user would probably be given the same IP address as before, if the interval before reconnecting was not more than about 20 minutes and if there were not many requests for IP addresses at the same time.. 

• Several companies provide ways to map dynamic 'numeric' IP addresses to a fixed domain name. This enables people on Internet to access computers that do not have a fixed numeric IP address by using their domain name, which 'follows' the numeric IP address, as it changes.
• Dynu Systems Inc in Minnesota, USA provide a free service with software called 'Dynu Basic Client' Version 2.0. Their commercial software is called ' Dynu Web Client' and provides the 'Dynu Premium Dynamic DNS Service', which costs US$24.99/year, but can be tried out for 30 days after installation. As soon as the client computer connects to Internet, the software sends the name of the computer and its new dynamic IP address to Dynu DNS servers, which update the DNS mapping tables with the new IP address, so that other computers can continue to connect to it using a 'fixed' name. In this way, you can host your own Web, FTP, Mail Server, Game Server or other TCP/IP Service. The software will provide a fixed address for  a Cable modem, xDSL, ISDN or Dialup services. Dynu can also provide a domain name for $24.99/year.
• Similar services are provided by 'DNS2GO' in Michigan, USA (who also sell Wingate software), 'DHS International' in Hong Kong and 'Selfhost' in France. 
• The above services map your computer to a domain name under the control of the company that provides the service. If you want to map your computer on an ADSL connection to your own domain name, this can be done in a complex manner: A BT Openworld FAQ notes that hammernode.com provide a service to update automatically your IP address to your own domain name. First create a 'vanity account' login with hammernode.com. Second, set up a 'vanity domain' (yourname.hn.co.uk) which will be used by the redirection process. Third, create a 'Virtual Domain Mapping login', using the box on the right of the hammernode.com home page.
  Then you have to alter the settings at the site where you registered your domain name, to use the name servers at hammernode.com. For example, if you have a domain name that is registered at ukreg.com, logon to it and alter the name server entries for your domain name from the ukreg.com name servers to the hammernode.com name servers. Wait for about 24 hours for the name server root to be updated then log onto hammernode.com and point your new root-verified domain at your recently created vanity domain. Finally, install a progam on your PC, such as 'DNS2GO', which will update the IP data when it is dynamically changed by BTOpenworld. If you use yiPost for this function, set one option there to 'Check local IP address'. 
• It is possible, but not necessarily acceptable to the service provider, to set up an email (STMP, POP3 and Finger) server on a dynamic IP ADSL line using, for example, the free software from 'argosoft' called 'ArGoSoft Mail Server' and 'Mercury'.
• A disadvantage of dynamic IP addresses is that you may acquire the IP address of someone else who had set up a service on that IP address, which will then 'map' to your computer when you acquire their IP address. When someone runs a game server, that IP address is registered in some central location and becomes visible to anyone in the world wishing to play that type of game. Typically, anyone looking for a game will ping (actually more than a ping, but that is what the gamers call it) every available server, sometimes repeatedly and will then pick one game and play. So every single player in the world looking for that game will make requests to every registered server. Several hundred an hour is not an unreasonable number for a game like Half Life. For example, if someone sets up the game called 'Half-Life' which can run on port 27015 as a server and you inherit their IP address, you may find large numbers of users trying to access your computer on UDP port 27015, to play the game. Most often, these attempts to access your computer will be logged by ZoneAlarm as 'attacks', even though they are not a cause for alarm. UDP is a broadcast protocol used for games servers, video and sound broadcast, etc. The problem will continue until their machines realized that the service is discontinued, so it is better to get another IP address. Another cause of multiple attempts to access a computer is when you start using Napster or other peer-to peer software. These attempted connections are other users eager to download MP3 files, etc.

12. Security

• The insecure WINS Client (TCP/IP) transport protocol. This protocol can be used by malicious users on Internet to gain unrestricted access to a networked computer. Whenever possible, computers that run Microsoft Windows with the insecure WINS Client (TCP/IP) transport protocol, should bind the protocol to a virtual 'Loopback Adapter', to prevent this. The protocol should not be disabled, as it is required for several essential communication functions. Exceptionally, if you need to access 'Samba' shares on locally- networked UNIX computers, you should not use a 'Loopback Adapter' for the WINS client (TCP/IP) transport protocol or disable the protocol. The WINS Client (NetBEUI) protocol can be run safely.
• Firewalls are recommended for all computers attached to potentially insecure networks and are essential for computers attached to ADSL lines. This is discussed in a PC World article on 10 October 2000. You can install a firewall before or after you have installed ADSL. Two products, BlackIce and ZoneAlarm (which is free for personal use), were recommended for PCs running Windows operating systems. I have installed the 'ZoneAlarm Pro' program. (Buy ZoneAlarm Pro 2.6 here) There is a patch for 'ZoneAlarm Pro'. I found that I had to configure 'ZoneAlarm Pro' on the host and client computers to use 'Internet Connection Sharing' as a host and client respectively, before the client computer could use the ADSL connection. 
• Note that PCs running Norton 'Firewall 2001' and Norton 'Internet Security (NIS) 2001' with the Alcatel USB modem software, may force a reboot occasionally, when viewing web pages. When the 'automatically reboot' setting in 'startup and recovery' is disabled in the system settings, this error causes a crash with a 'blue screen of death' instead, requiring a manual restart. Symantec have been aware of this problem for about 6 months now, but have not provided a fix so far (6 January 2001), although it is possible that the problem is with the Alcatel driver. If you have this problem, install a different firewall.
• After setting up a firewall, I recommend that you check the security of your computer. There is a scanner at Gibson Research Corporation that will show you where your security can be tightened. You can check a subnet and its network details, including MAC id, IP addresses and possible vulnerabilities,. using the free software 'LANguard Network Scanner'.
• Attempts to intrude on your computer can be reported to DShield.org who can also supply software to automate reporting.

13. Networking other local computers to use an ADSL connection: ICS

I have a guide on how to setup  Microsoft's 'Internet Connection Sharing' (ICS) to enable other computers on a local network to use a USB ADSL connection. Networked (client) computers will obtain their network IP addresses from the (host) computer which is connected directly to the USB ADSL router. Note that use of ICS on BT's USB routers may be contrary to their 'Terms and Conditions' and ICS is not supported by BT, so check before installing it. Business users of the RJ45 ADSL modems simply need to add the network addresses provided for them for each computer on their network, to connect to local computers and Internet. Advanced network installations that need to hide the local network from Internet users, can use 'Network Address Translation' (NAT) routers which link to the RJ45 ADSL modem.

14. Networking  a local computer through its ADSL connection to a remote computer: VPN

Networking to distant computers through ADSL is usually best done using Virtual Private Network (VPN) software. VPN runs on the local client computer, which can then tunnelling across ADSL to a distant computer, which is configured to run VPN in host mode. All data is encrypted between the two networked computers. Many VPN protocols 4.

Efficient Networks  EN 5861 with setup details.

PCI ADSL router.

A combined ADSL modem and router (Prestige 642R), which can replace the Alcatel router, is available from SEQ @ £400. One end plugs into the ADSL socket and the other into a hub connecting each computer and avoids the need for an USB connection.

Alcatel have produced an ADSL wireless router that works well with Orinoco PC cards and BT Openworld, as described by David Tong.

Seg AR601.

Vigor2200USB router, which shares a USB router with networked computers, provides a firewall and VPN functions. It supports BT's USB ADSL modem directly.

Webramp 600i router/modem/hub

18. Planned improvements and updates of BT's ADSL services

RADSL In June 2001, BT in conjunction with the ADSL supplier BTIgnite, are running a 'limited volume, invitation only' trial of an 'extended reach' ADSL product  (RADSL), which uses a USB rate-adaptive modem to increase the ADSL 'footprint' around an enabled exchange to about 5.5kms (or a 55dB line loss) in return for a slightly reduced upload speed. This will vary from 250k to 64k, download speeds remain the same. No announcement of a public service is likely before the end of 2001.

 BT plan to trial a 'Wireless Hub' later in 2001. This will allow users to connect, for example, a Hi-Fi system and TV to a broadband connection, which will provide multi-channel digital internet radio around the house and other wireless networked functions.

G.SDSL is being tested in Europe as a possible successor for ADSL. It transmits at up to 2.3 mbps and can link to sites over 3 miles from an exchange using repeaters.

Go to the 'home page'

Go to the 'computer index page'

© cspry@sghms.ac.uk. Department of Biochemistry & Immunology, St. George's Hospital Medical School, London SW17 0RE, UK. Phone +44 20-8725 5819; fax +44 20-8725 5821. This page was last updated on 29 May 2002 22:10:30.

Complaints about BT's Openworld service should be sent by email to complaints@btopenworld.com or given by phone 0845-6007020 or 0845-6007030. Each complaint is allocated an adviser.

16. 'Business Plus' services with a fixed IP address

Eugenio Mastroviti has provided me with his experience of the 'business' service provided by BT.

• 'Business plus' customers are given a 'SpeedStream' 5861 router which has an RJ45 network port. This has a fixed IP address, which is not routable, as any locally networked computers are held behind a NAT service. For the same reason, computers that are networked to the ADSL computer with the fixed IP address are not 'visible' to external computers. While this makes the network more secure, some protocols do not work properly. Streaming video only works about half of the time. Servers cannot be run from the network, because the IP address is not routable. I am told by BT technical support that they are now providing static, routable IP addresses to new customers. They will provide these for current customers, starting in the summer. They also suggested, that if I needed urgently a routable IP address, my service could be reconnected but this would cost the £300 business installation fee again.
• The 'Business plus' service, apart from these snags, runs well. Windows 98, Windows 2000, Linux (SuSE and RedHat) and Solaris 8/Intel will work correctly with any good quality network card.
• Although non-Microsoft operating systems are not supported by BT, their use is not illegal. I have a dedicated firewall consisting of a Pentium 90 bought for $35 and Linux, to which 3 machines are currently connected. While it is not protecting the network, as I am behind NAT, it will come in useful after next summer. Meanwhile, I am running a proxy server on it, which increases the browsing speed of the networked computers.

17. Alternative routers to the standard Alcatel USB router

Routers can be bought to replace the Alcatel USB modem, which is usually provided for ADSL connections and is owned by the service provider. The main advantage of replacement routers, is that they maintain a connection to Internet without needing a computer connection and they can provide NAT and other secure functions for a local network using RJ45 connectors. Note that some ADSL service provider agreements specify that their routers must be used, but this may alter, now that 'better' alternatives to the Alcatel USB router have become available. The list below is only some of the available hardware. I have no experience of using any of the following:

• The D-Link DSL-504 ADSL 4-port router. There are reviews at it-reality.co.uk and adslguide.org.uk with guides to installing it under Windows 2000. 
• The AR601 router, which is cheaper but has less functions than the DSL-504.
• Efficient Networks  EN 5861 with setup details.
• PCI ADSL router.
• A combined ADSL modem and router (Prestige 642R), which can replace the Alcatel router, is available from SEQ @ £400. One end plugs into the ADSL socket and the other into a hub connecting each computer and avoids the need for an USB connection.
• Alcatel have produced an ADSL wireless router that works well with Orinoco PC cards and BT Openworld, as described by David Tong.
• Seg AR601.
• Vigor2200USB router, which shares a USB router with networked computers, provides a firewall and VPN functions. It supports BT's USB ADSL modem directly.
• Webramp 600i router/modem/hub

18. Planned improvements and updates of BT's ADSL services

RADSL In June 2001, BT in conjunction with the ADSL supplier BTIgnite, are running a 'limited volume, invitation only' trial of an 'extended reach' ADSL product  (RADSL), which uses a USB rate-adaptive modem to increase the ADSL 'footprint' around an enabled exchange to about 5.5kms (or a 55dB line loss) in return for a slightly reduced upload speed. This will vary from 250k to 64k, download speeds remain the same. No announcement of a public service is likely before the end of 2001.

 BT plan to trial a 'Wireless Hub' later in 2001. This will allow users to connect, for example, a Hi-Fi system and TV to a broadband connection, which will provide multi-channel digital internet radio around the house and other wireless networked functions.

G.SDSL is being tested in Europe as a possible successor for ADSL. It transmits at up to 2.3 mbps and can link to sites over 3 miles from an exchange using repeaters.

Go to the 'home page'

Go to the 'computer index page'

© cspry@sghms.ac.uk. Department of Biochemistry & Immunology, St. George's Hospital Medical School, London SW17 0RE, UK. Phone +44 20-8725 5819; fax +44 20-8725 5821. This page was last updated on 29 May 2002 22:10:30.