ADSL offers a cheaper and faster service than ISDN. ISDN works by providing two voice channels or a 128 Kbps data channel while ADSL is predominantly a data pipe providing an asymmetrical bandwidth of up to 6 Mbps downstream and 640 kbps upstream. However, the ADSL network is an overlay network and therefore does not require the expensive and time-consuming switch upgrades that held ISDN back for so long.

ISDN is only available in two speeds: 64 Kbps and 128 Kbps, both of which are significantly slower than most DSL connections. ISDN is subject to additional per-minute fees in many locations. ISDN fees can easily range into the hundreds of dollars on a monthly basis. Internet service providers often charge $30-$150 a month to provide Internet access to ISDN customers.

You will be able to get ADSL if the local exchange supports ADSL and you order an analogue telephone service (extra charge) to be used for the ADSL service. This service would be charged a standard telephone line rental. How many IP addresses do I get with my ADSL service? You will receive at least one static IP address with your ADSL order.

ADSL gives you a private and secure connection over a single telephone line, while cable modems share their bandwidth with multiple users. In essence, this means that connection speeds for cable modems will vary according to the number of users who are using the same line. Cable modems are also limited to homes which can support two-way cable modem transmissions, whereas ADSL is available to anyone with a phone line.

ADSL provides you with an always on, high-speed, secure connection to the Internet. With ADSL you do not share your bandwidth from the ISP with other users. In contrast, competing technologies share bandwidth on the same cable: your performance with these other technologies can vary greatly, depending on the number of users connected.

Basic ISDN effectively converts your telephone line to digital with two 'channels', each of which can carry a telephone conversation or data at 64Mb/s. When neither phone line is in use, the data channels can be combined to give 128Mb/s, which puts it at the bottom end of "Broadband". The drawback of ISDN is its price - Telstra have considered it a premium business service, and have priced it out of the reach of residential users.

Yes, however the line has to be re-graded to an analogue line, and BT charge to do this, you are also liable for any terms left on the ISDN contract. Once the line has been regraded, it will be checked for suitability for ADSL. There is a chance the line is not suitable and BT will charge to convert it back to ISDN.

ADSL can’t be installed on ISDN lines, so either you need a separate new (analogue) phone line or for the ISDN to be converted back to an analogue service.

Eicon has demonstrated ADSL over ISDN operation using the G.992.2 Annex B standard. Currently shipping products do not support ADSL over ISDN. The reason is that an ADSL connection may share the standard telephone wiring, however, ADSL itself is only connected to the Internet. Since a Diva ADSL modem only accesses the ADSL connection, it too is only connected to the Internet.

According to the actual Swisscom phone rates (ca.Frs 4.--/hour), this solution is more convenient for connections above 3.5 hours a day (break-even point).

ADSL provides a dedicated service over a single telephone line; cable modems offer a dedicated service over a shared media. While cable modems have greater downstream bandwidth capabilities (up to 30 Mbps), that bandwidth is shared among all users on a line, and will therefore vary, perhaps dramatically, as more users in a neighborhood get online at the same time.

POTS codecs are ideal for grab-it-and-go situations. When quality is paramount, however, ISDN is the clear choice. Here is a quick summary:

ISDN delivers the highest quality audio, with the low delay necessary for fast-paced exchange. POTS, on the other hand, are perfect for spontaneous broadcasts. Here is a quick summary of each technology's advantages:

DSL will be the cause of ISDN's demise for several reasons: - ISDN is only available in two speeds: 64 Kbps and 128 Kbps, both of which are significantly slower than most DSL connections. - ISDN sometimes offers dedicated, always on access but not always. Furthermore, ISDN is subject to additional per-minutes fees in many locations. ISDN fees can easily be in the hundreds of dollars on a monthly basis. -ISP's will charge between $30-150 a month to provide Internet access to ISDN customers.

ADSL provides a dedicated service over a single telephone line; cable modems offer a dedicated service over a shared media. While cable modems have a greater downstream bandwidth capabilities (up to 30 Mbps), that bandwidth is shared among all users on a line, and will therefore vary, perhaps dramatically, as more users in a neighborhood get online at the same time.

Unlike cable modem service that relies on a network shared by all cable subscribers in one particular area, ADSL's technology provides a dedicated connection between your home and telephone line secure network. Your Internet ADSL connection also provides you with your own, dedicated bandwidth. Performance is not degraded during heavy traffic periods.

Speed comparisons are very hard to make since there are a number of influencing factors - the contention ratio, web site server speed, international bandwidth constraints, etc. However, the following shows the differences in potential speeds: Comparison to 56K home modem bandwidth: Dial-up Modem 28-56kbps: 0.5-1.0x ISDN 64-128kbps: 1.1x-3.3x ADSL based services 256Kbps-2Mbps: 4.

The two services are NOT the same. ISDN provides two voice channels or a 128 Kbps data channel while ADSL is predominantly a data pipe providing an asymmetrical bandwidth of up to 8 Mbps downstream and 1 Mbps upstream under good conditions. However, an ADSL access network will be an overlay network and therefore will not require the expensive and time-consuming switch upgrades that held ISDN back for so long.

You cannot use both WAN interfaces to connect to internet (via the same ISP or different ISP's) at the same time, as the router wouldn't know which internet connection you wanted. But you can have the ADSL connected to the Internet and use the ISDN for a dial-in teleworker or a VPN to a branch office. Technically speaking, where the ISDN is being used to route to a specific directly-dialled subnet. If you have a remote office or teleworker which only has ISDN (i.e.