What is ISDN?

ISDN is a high-performance service that delivers broadcast-quality voice and continuous, extremely reliable data transmission.

Continuous data transmission makes it ideal for use with EPOS machines and intelligent tills in shops, especially in areas with patchy broadband coverage.


For small businesses that cannot afford any breaks in data transmission.

ISDN2 System customers can connect to a small switch, like the BT Quantum, and have up to 60 channels (sold in pairs).

Channels can be bonded to increase bandwidth for things like reliable video-conferencing.


For large businesses that need high-quality video-conferencing, consistent transfer of large data files, or that operate call centres.

As well as being able to have an unlimited number of channels (sold singularly), ISDN30 customers can also bond channels to increase bandwidth.

ISDN30 supports WAN to link 2 or more sites.