ISDN or ADSL - what's the difference ?

tair_bashir

Hi,

Can anyone let me know the difference between ISDN & ADSL ?

Will an ISDN modem work on an ADSL line ?

many thanks in advance.

SimplyAUser

ISDN is a dedicated line and the modem (sometimes people use a router) comes pre-programmed with the address of the company to call (or sometime it has encoded BT line number).

You cannot use ISDN modem or router with ADSL.

ADSL is used by overloading the telephone line (no special line required).

ADSL router/modem will not work with ISDN line.

flang

ADSL uses a different frequency to enable internet and telephone over a shared line.
ISDN isnt used very much anymore.

mah_jong

ISDN can be used where there is no broadband option.

mike_paterson

ISDN is also much slower and more expensive than Broadband

ManAtHome

If you have the BT Home Highway (think that's what it was called), you can get it switched back to a normal line for ADSL use (it does cost, but can't remember how much).

moomintroll_3

ISDN (Integrated Services Digital Network) is a dedicated digital line rated at 64K. When you order this service from BT they deliver a grey box on the wall which has two sockets, both of which can dial independently at 64K or be bonded together to make a 128K connection (hence why they call the service ISDN2).

ISDN is however, still a dialup connection...

ADSL (Asynchronous Digital Subscriber Line) is a service delivered over a PSTN (Public Service Telephone Network - a normal phone line) line and uses a different (higher) frequency to the voice carrier on that line which is why you can have ADSL and voice over the same line permanently.

ISDN and ADSL are incompatible products and, if you have an ISDN line, you can request that it is converted back to a PSTN line along with a broadband order. You cannot use an ISDN modem or router on a PSTN line.