More and More of Our Users Are Deserting Their Dialup Modem in Favour of an Asymmetric

Broadband

More and more of our users are deserting their dialup modem in favour of an Asymmetric Digital Subscriber Line (ADSL) commonly known as broadband. We know this is happening, because the Helpdesk is asked an increasing number of questions about broadband.

A broadband connection has two advantages over a dialup modem. First of all it is faster, and secondly it allows you to use the telephone while at same time you, or another member of your household, can remain on-line. Broadband, which is anything between 10 and 50 times the speed of a reasonable dialup connection, makes an enormous difference to the perceived speed of the Internet. It is an interesting comment on our perception of processing speed that many people report the impression that broadband is more or less as fast as the University’s network, whereas it is in fact 500 to 1000 times slower. There is a lot more involved in the ‘speed of the Internet’ than the capacity of the underlying network connections. The difference in line speed between dialup and broadband makes a qualitative difference to the experience of using the Internet. Processes such as downloading your email or updating your virus definition strings, which over a modem can be fraught with anxiety, are much easier, quicker and less likely to fail. You can afford to try things out and explore more of the hits from your Google searches. Many people who just couldn’t be bothered with the Internet over dialup are now keen users.

While the joys of broadband speak for themselves, our Helpdesk experience suggests that we need to draw attention to some associated problems. This article is not intended to discourage you from taking advantage of the power of broadband, but to correct some misapprehensions and indicate how far IT Services can be called upon to support you in the use this remarkable technology.

The variable quality of broadband services

There are now many broadband Internet Service Providers (ISP), such as Demon, BT, AOL, Tiscali, Plusnet, Wanadoo and others. They each provide a range of different products at different prices. The main points of difference are the guaranteed speed of the connection, and the sort of Internet services, such as email, that are packaged in with the basic broadband deal. Some packages also place a limit on the volume of data you can download in a month, with excessive downloads attracting an additional charge.

Look carefully at the terms of any broadband package you are thinking of buying. If you are offered speeds of ‘up to 2 megabits per second’ (or as it might be phrased, ‘two meg’) remember that this might include times when the speeds are very far from 2 megabits per second. You should understand that you are sharing your ISP’s bandwidth with its other customers. Some packages include a guarantee to limit the number of contending users, which amounts to a guarantee that your speed will not be reduced too far. If your ISP offers a more expensive deal guaranteeing a certain speed, this should remind you that the cheaper deals contain no such guarantee.

Broadband connections depend crucially on the quality of your phone line, and our impression is that a lot of the phone lines in and around St Andrews are inadequate for high-speed broadband. Your ISP (even if it is BT under a different hat) will accept no responsibility for the good or bad quality of your phone line. It is of course small consolation to you to know that your ISP’s servers have almost 100% reliability, if you are repeatedly cut off because of faults on your line.

Many broadband deals include a free ADSL modem – sometimes referred to as a router, although this name is more properly applied to more sophisticated devices that you can buy to give a more reliable and flexible broadband connection. ADSL modems typically plug into one of your computer’s USB ports, whereas the routers plug into the Ethernet port. A modem or router is needed in order to link your computer to broadband, and the quality of this device is another factor that can affect the reliability of your service. It’s unfortunately true that these give-away devices tend to be less robust than those that can be purchased for prices of around £65. This doesn’t mean that the cheaper option will not work, but if you are having problems of reliability, one of the things you should consider is the quality of your modem or router.

A non-St Andrews IP address

When you are connected to the Internet by broadband you will be given an IP address, which is a unique address on the Internet, and which consists of four numbers, such as 80.229.165.237. This address may change from one session to another or it may be fixed and yours for as long as you subscribe to your ISP – it depends on whether your ISP’s deal includes a fixed IP address. But fixed or not, the IP address given you by your ISP does not belong to the University of St Andrews IP address range. This is no different from what happens if you use a dialup connection to an external ISP, but if you use the University’s dialup service (SARA) you do get a University IP address, just as though you were directly connected to the network.

Not having a University IP address has two consequences which you should take account of. First, some of the licensed databases and journals provided through the Library are only accessible from within the University’s network, which means that you have to have an IP address beginning 138.251. If you are outside this range you can access much of the copyright material by signing on with an ATHENS password, but there are journals for which ATHENS doesn’t work and for which you must have a University IP address.

The second major consequence of not having a University IP address is that, although you can still read your St Andrews mail, you cannot send email from a desktop email client such as Eudora to external addresses using the St Andrews mail servers. In other words, you have to configure Eudora to use the mail service offered by your ISP, so it is important to make sure your broadband Internet package offers the sort of mail service you want. If you want to send mail using Eudora over broadband, your ISP must offer you access to an SMTP server. Further, with some ISPs you may find that when you send mail using their SMTP server you are unable to give your St Andrews email address as your ‘return address’. Many people who use broadband opt to handle their University email with WebMail.

A solution to the problem of the IP address

You can set up a Virtual Private Network (VPN), which gives you a St Andrews IP address, and which therefore can be regarded as the broadband equivalent of SARA. IT Services distributes a piece of software called the Cisco VPN client, which you can download and install on your PC or Mac (MacOS X only). If you sign-in to the VPN client with your St Andrews username and password, you will be allocated a St Andrews IP address, which will be effective for as long as you remain connected to the VPN. This in turn will permit you to use the University’s web cache, enabling you to access licensed Library material as though you were physically connected to the University’s network. While using the VPN you will also be able to send mail through the University’s SMTP servers, and take advantage of other network services provided by the University.

It seems that the VPN is particularly subject to disruption caused by a poor quality connection. Broadband connections do not remain continuously active. The transient interruptions that occur are hardly noticed when you are browsing the web or sending or receiving email, but the VPN client is affected by them. You will find, if your line quality is bad, that you are disconnected fairly frequently from your VPN, and that you have to keep re-connecting.

Security

When connected by broadband you are as liable to attack across the network as if you are using a direct network connection. It is essential to keep your anti-virus software up-to-date, and to apply all the security updates for your operating system. The Cisco VPN client, which includes a firewall feature, appears to be incompatible with some other common firewall software, including that provided with F-Secure Client Security v5.5. Because people largely use broadband and the VPN on their computers at home, it is not easy for ITS staff to determine the exact cause of these difficulties, nor to determine why on some machines the same incompatibilities do not arise. Cisco’s own documentation is guarded over these issues of compatibility. Issues surrounding firewalls and the VPN client are still under investigation by IT Services.

Limited support for broadband users

This brings us to the third drawback of using a broadband connection. Although IT Services can give some broad general advice on broadband, such as is given in this article, we can only offer a very limited amount of specific support and troubleshooting. The reasons for this should be clear from what has been said. The behaviour of your broadband connection will depend on many things that are outside the control and beyond the knowledge of the Helpdesk and the rest of IT Services. The details of your package deal with your ISP, the quality of your ADSL modem and your phone line, and the general configuration of your computer will all affect the service your receive.

Although the symptoms that you suffer when your broadband connection is unreliable will seem to have to do with services offered by IT Services (such as your use of email, access to licensed and protected web material, access to shared drives and the working of the VPN) if you are using broadband the chances are that the cause of the problem is to be found in the variable quality of your broadband.

You will have a better chance of receiving advice on your use of broadband if you adopt a configuration which approximates to the one that we have tried out and used ourselves.

ISP: Demon

Broadband Package:

ADSL router:

VPN client: Cisco VPN client v4.6/4.7

Firewall:

Phone line: approved by BT as appropriate for broadband at the speeds guaranteed by your ISP

The more your configuration diverges from this the more likely we are to have to hedge around our advice with ifs and buts.

As this article makes plain we are not in a position to make clear and unequivocal policy recommendations on broadband and related matters. As we develop a firmer policy we shall place guidance and information on the ITS website, along with links to the useful body of expertise that exists on external websites. See

http://www.st-andrews.ac.uk/its/networks/broadband