ISDN stands for "Integrated Services Digital Network," and using the same telephone lines that modems use, ISDN delivers a five-fold speed improvement (up to 128 Kbps).

ISDN is a collection standards for end-to-end digital communication over the public telephone network. ISDN service can be carried over the existing telephone network infrastructure and therefore is available in almost all markets.

With a traditional dial-up account, your company can access the internet via an analog modem with speeds up to 56k.