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Technology evolves at a rapid-fire pace. That’s why we’ve built an easy-to-use glossary to help you better understand the terms, technologies and trends that impact your business.

Integrated-Services Digital Network (ISDN)

An early dial-up predecessor of the DSL family that can support up to 128 kbit/s symmetrical service. ISDN is a usage-based service offered by telephone companies that is being rapidly eclipsed by DSL. ISDN is a circuit-switched technology.