The different types of ADSL
The following is an article that was published on makr.dk on 21 December 2001.
I wrote it at a time when TDC had gradually built up such a large number of ADSL variants from so many different subsidiaries that it was impossible to keep track of them all.
The article naturally became outdated quite quickly, but was quoted a number of times in various contexts.
An interesting fact is that I wrote the article whilst standing in a Telebutik for a whole day wearing a boiler suit. It was part of a Christmas campaign for ADSL, and part of the concept was to send project managers from TDC Internet out amongst the customers. It was a very good idea, but cordless phones were far more popular that year than an internet product that people could neither pronounce nor spell.
TDC has several different ADSL products on the Danish market.
The reason there is more than one is that each product is aimed at its own customer segment and tailored to suit it.
Broadly speaking, there are three different products and one spin-off
Pro@ccess ADSL, which is primarily aimed at the business sector and the more technically-savvy private user
Netexpress ADSL, which is TDC Internet’s offering for an ADSL connection to the residential market
Broadband|ADSL, which is TDC Tele Danmark’s bundled product sold alongside a standard telephone subscription or an ISDN subscription.
In addition, there is the Netexpress variant Boomtown ADSL, which is technically identical to NetExpress but is aimed primarily at online gamers and includes access to the Boomtown online gaming environment. The speed is also specially tailored to the needs of online gamers.
Prices for the four products fluctuate constantly and can be difficult to compare, precisely because they include different features.
Essentially, you should choose based on your technical and practical needs rather than looking solely at the price.
There are also a number of product-related differences, which I will attempt to explain below.
NetExpress was the first ADSL solution in Denmark and was launched in the summer of 1999. Since then, the product has been updated on two occasions. The first time was when a router became a standard feature of the product, and the second time was when the router became an optional extra.
The earlier versions are still in circulation but are no longer available for purchase. However, version two is identical to the current product, provided you opt for the standard router.
In its current form, the product is technically based on an ADSL connection which, at the customer’s end, terminates in an Ethernet socket.
You connect to the internet via this socket using dialling software, in many ways similar to dialling via standard telephone lines.
If you have more than one PC, you cannot use this solution, but must instead choose a router as an additional product.
In that case, it will be the router that connects to the internet, and it will then share the connection with the devices connected ‘to the back’ of the router.
The router uses NAT and assigns addresses to the devices behind it via DHCP
The router has only one Ethernet port, so you’ll need to connect it to a switch or hub to connect more than one device.
NetExpress is independent of your telephone subscription, so you can, for example, have a fixed dialling plan with another telecoms provider even if you have NetExpress.
NetExpress is best suited if you either have just one computer or have more than six computers and also wish to use a different telecoms provider.
Boomtown ADSL is technically the same as NetExpress but is provided at a speed that makes it suitable for online gaming, namely 512/512
At the same time, you receive a membership of the gaming site Boomtown.
Pro@ccess ADSL is the ADSL version of the dedicated lines, aimed primarily at the business sector.
Pro@ccess is also available in a new and an older version, with the older version differing in that it terminates at the customer’s premises via an ATM socket.
The newer version terminates at the customer’s premises via an Ethernet socket but is otherwise identical, apart from a different router. The Ethernet version has the advantage of allowing the use of significantly cheaper routers than the previous ATM model, should you wish to use your own.
The router is supplied pre-configured with support for the most commonly used services: web, news, email and DNS. You cannot change this configuration yourself.
Pro@ccess is the most professional product in TDC’s range and can be expanded in several
ways, including with a firewall or 24-hour monitoring.
The product comes as standard with one static IP address, but by subscribing to the ‘Link’ add-on or by using your own router, you can be allocated your own routed network comprising, for example, eight IP addresses. You simply need to submit the application to RIPE yourself.
Pro@ccess is therefore a subscription offering many possibilities, and if you need to run specialised or critical applications over your ADSL line, Pro@ccess is an obvious choice.
Broadband|ADSL is a combined telephony and ADSL product provided by TDC Tele Danmark (unlike the other products, which are provided by TDC Internet, a separate company).
The product includes a ‘FavoritAftale’ agreement which offers benefits and discounts, but excludes the use of other providers for telephony.
BB|ADSL differs technically from the other two solutions in that it is possible to connect several PCs directly to the ADSL modem (albeit via a switch or hub, but not necessarily through a router).
Each connected computer is assigned its own IP address via DHCP, and BB|ADSL differs from all other products on the Danish market in that it provides two public addresses as standard.
Public addresses are a clear advantage if you use more advanced applications such as games, chat, NetMeeting, etc.
If you have more than two computers, you can purchase additional IP addresses, up to a maximum of six.
The disadvantage of this solution is that you may be allocated IP addresses in different so-called subnets. In short, this means that traffic between the individual machines (e.g. file transfers) must be sent over the internet, resulting in low speeds.
There are several ways to get round this problem, but none are entirely ideal.
BB|ADSL is the best option if you want a comprehensive communications solution and have one or more computers that rarely exchange large amounts of data.
Static or dynamic IP?
When you’re connected to the internet, you have an address that other computers use to connect to your machine. If you have programmes running on your computer that other people need to be able to access (e.g. an FTP server), a static IP address can be an advantage.
This means you always have the same address and you can, if necessary, set up a DNS entry for this address, e.g. hjemme.makr.dk.
Dynamic addresses can change from time to time, so you cannot be sure of always keeping the same address. However, this is less of a problem, as services such as dyndns.dk offer the option of registering a fixed name with them. In this way, makr.dyndns.dk will always point to the current IP address you have been allocated.
The Pro@cces product always comes with a static IP.
With Netexpress and Boomtown, you are generally assigned a dynamic IP address, but it is possible to obtain a static IP address free of charge.
Broadband|ADSL comes as standard with two dynamic IP addresses, but you can opt for one static IP address instead.
In the vast majority of cases, the advantages of having two public IP addresses will outweigh the disadvantages of having to use, for example, dyndns.dk