Editing CompuServe (section)

===Selling connectivity===
Another major unit of CompuServe, the CompuServe Network Services, was formed in 1982 to generate revenue by selling connectivity to the nationwide packet network CompuServe had built to support its time-sharing service. CompuServe designed and manufactured its own network processors, based on the DEC [[PDP-11]], and developed all the software that operated on the network. Often (and erroneously) termed an [[X.25]] network,{{citation needed|date=August 2024}} the CompuServe network implemented a mixture of standardized and proprietary layers throughout the network.

One of the proprietary layers was termed Adaptive Routing.<ref>{{Cite thesis |last=Cornett |first=Robert Douglas |title=Hierarchical Routing for the CompuServe Network |degree=M.Sc. |publisher=Wright State University |oclc=14389250 |year=1985}}</ref> The Adaptive Routing system implemented two powerful features. One is that the network operated entirely in a self-discovery mode. When a new switch was added to the network by connecting it to a neighbor via a leased telephone circuit, the new switch was discovered and absorbed into the network without explicit configuration. To change the network configuration, all that was needed was to add or remove connections, and the network would automatically reconfigure. The second feature implemented by Adaptive Routing was often discussed by network engineers, but was implemented only by CNS {{En dash}} establishing connection paths on the basis of real-time performance measurements. As one circuit became busy, traffic was diverted to alternative paths to prevent overloading and poor performance for users.

While the CNS network was not itself based on the X.25 protocol, the network presented a standard X.25 interface to customers, providing dial-up connectivity to corporate hosts, and allowing CompuServe to form alliances with private networks [[Tymnet]] and [[Telenet]], among others.<ref>{{Cite web |date=March 26, 2013 |title=How the Bell System Missed the Internet 2 |url=https://talkingpointz.com/how-bell-missed-the-internet-2 |archive-url=https://web.archive.org/web/20190709062424/https://talkingpointz.com/how-bell-missed-the-internet-2/ |archive-date=July 9, 2019 |access-date=July 9, 2019}}</ref> This gave CompuServe the largest selection of local [[Dial-up Internet access|dial-up]] telephone connections in the world, in an era when network usage charges were expensive, but still less than long-distance charges. Other networks permitted CompuServe access to still more locations, including international locations, usually with substantial connect-time surcharges. It was common during the early 1980s to pay a $30-per-hour charge to connect to CompuServe, which at the time cost $5 to $6 per hour before factoring in the connection-time surcharges. This resulted in the company being nicknamed ''CompuSpend'', ''Compu$erve'' or ''CI$''.

CNS has been the primary supplier of dial-up communications for credit-card authorizations for more than 20 years, a competence developed as a result of its long-time relationship with [[Visa International]]. At the peak of this type of business, CompuServe transmitted millions of authorization transactions each month, representing several billion dollars of consumer purchase transactions. For many businesses an always-on connection was an extravagance, and a dial-up option made better sense. This service presently remains in operation, as part of Verizon (see below). There are no other competitors remaining in this market.

The company was notable for introducing a number of online services to [[personal computer]] users. CompuServe began offering [[e-mail|electronic mail]] capabilities and technical support to commercial customers in 1978 using the name InfoPlex, and was also a pioneer of the [[online chat|real-time chat]] market with its [[CB Simulator]] service introduced on February 21, 1980, as the first public, commercial multi-user chat program. Introduced in 1985, EaasySABRE, a customer-accessible extension of the [[Sabre (computer system)|Sabre]] travel system, made it possible for individuals to find and book airline flights and hotel rooms without the help of a [[Travel agency|travel agent]].<ref>{{Cite news |last=Gutis |first=Philip S. |date=December 23, 1989 |title=More Trips Start at a Home Computer |language=en-US |work=The New York Times |url=https://www.nytimes.com/1989/12/23/style/more-trips-start-at-a-home-computer.html |access-date=April 5, 2020 |issn=0362-4331}}</ref> CompuServe also introduced a number of [[online game]]s.