Networking with ADSL
A guide covering the setting up of ADSL routers only (Ethernet).  Setting up an ADSL modem (USB) is as straightforward as setting up a standard modem and is not discussed here.  You should have received an instruction manual and driver CD to help you with your ADSL modem.

Important: These tutorials should serve as a guideline only.  We do not officially give technical support for networking issues and this guide should help you resolve many of the questions we have been asked over the phone.  Please note that our telephone support agents are not in a position to follow up on this tutorial, nor will they be able to help with specific router configuration issues.  Setting up routers and networks is certainly not for the faint-hearted.

The self-install Office range of ADSL services, together with the older BT-installed products ADSL 500, 1000 and 2000, allow you to hook up more than one computer to your connection, giving your LAN high-speed access to the Internet.  This is great news for business, giving 24-hour a day access to the Web and e-mail at a price that would have been unthinkable less than 12-months ago.

We assign one static IP to each ADSL account as standard. This is suitable for most networking needs. If you require more than one IP you can apply to our support team who will assess your requirements.

The single IP address service we call 'NAT', since you could use NAT and Port-forwarding on your ADSL router equipment to forward Internet traffic to specific machines (servers) on your internal network.  You are provided with a single static IP address with this service.  You may like to note that this is different to some ISP's who use NAT at their end in order to provide you with service.  (An example setup of a Single-IP NAT network is illustrated below).


A Single IP (NAT) setup example

The multiple IP address service we call 'No-NAT', since you most likely would be using this option to provide Internet access via a public IP address to a specific machine (server) on your LAN.  You are provided with a block of four IP addresses with this service.  Some degree of knowledge of IP and networking is strongly recommended before choosing this option.

Your block of four IP's is made up of:

• a network address that is used to route traffic to and from your network
• an IP address that is assigned to your external interface upon connection
• a 'spare' IP address that you can assign to a machine on your LAN to make it publicly available
• a broadcast address that is used by all the machines on your network
  
  

You can see then that in choosing the four-IP No-NAT option you are in fact given a single public IP address to assign to a machine of your choosing.  This would more than likely be a Unix or NT box with more than one Ethernet interface (see below).  There are of course many different ways that you might connect your server to the rest of your internal network and the use of additional routers or switches might be employed.


A four IP (No-NAT) setup example

What should be clear is that the No-NAT option requires more equipment and a more advanced knowledge of networking.  There is in fact little that can be achieved by using No-NAT that cannot be achieved using NAT and port-forwarding.  We would strongly advise our customers to only choose No-NAT if there was a specific reason that would make it a compulsory requirement.

How to set up your network
The following guides show how you might set up your router and the internal PC's on your LAN.  They are meant as a guide only and should serve to help understand the principles involved that will allow you to successfully set up your connection.  Please note that the public IP addresses used are for example only and you should use the IP addresses that are issued to you individually.  You are informed of your connection details upon signup and, if choosing No-NAT, you should make a note of the IP range assigned.

The equipment shown in the guides here was chosen primarily to show two different interfaces that you might come up against when configuring your ADSL router and is not meant to imply that we recommend any particular manufacturer or type of connectivity equipment (although we would like to thank both Insight and Nascent Technologies for their assistance in compiling this information).

In all cases we have chosen to show how to set up MS Windows tm. for the host machines on your network.