Editing Internet access (section)

====Integrated Services Digital Network====
[[Integrated Services Digital Network]] (ISDN) is a switched telephone service capable of transporting voice and digital data, and is one of the oldest Internet access methods. ISDN has been used for voice, video conferencing, and broadband data applications. ISDN was very popular in Europe, but less common in North America. Its use peaked in the late 1990s before the availability of DSL and cable modem technologies.<ref>{{cite book |author=William Stallings |title=ISDN and Broadband ISDN with Frame Relay and ATM |edition=4th |publisher=Prentice Hall |year=1999 |page=542 |isbn=978-0139737442 |url=http://www.pearsonhighered.com/educator/product/ISDN-and-Broadband-ISDN-with-Frame-Relay-and-ATM-4E/9780139737442.page |url-status=live |archive-url=https://web.archive.org/web/20150924071103/http://www.pearsonhighered.com/educator/product/ISDN-and-Broadband-ISDN-with-Frame-Relay-and-ATM-4E/9780139737442.page |archive-date=2015-09-24 }}</ref>

Basic rate ISDN, known as ISDN-BRI, has two 64&nbsp;kbit/s "bearer" or "B" channels. These channels can be used separately for voice or data calls or bonded together to provide a 128&nbsp;kbit/s service. Multiple ISDN-BRI lines can be bonded together to provide data rates above 128&nbsp;kbit/s. Primary rate ISDN, known as ISDN-PRI, has 23 bearer channels (64&nbsp;kbit/s each) for a combined data rate of 1.5&nbsp;Mbit/s (US standard). An ISDN E1 (European standard) line has 30 bearer channels and a combined data rate of 1.9&nbsp;Mbit/s. ISDN has been replaced by DSL technology,<ref>{{cite web | url=https://www.ciscopress.com/articles/article.asp?p=2832405&seqNum=5 | title=Selecting a WAN Technology (1.2) > WAN Concepts &#124; Cisco Press }}</ref> and it required special telephone switches at the service provider.<ref>{{cite web | url=https://books.google.com/books?id=pxcEAAAAMBAJ&dq=isdn+adsl&pg=PA68 | title=Network World | date=23–30 December 1996 }}</ref>