The original purpose was to connect low-speed dumb terminals to a central time sharing host in Toronto.
It was soon modified to allow a terminal to connect to an alternate host running the SHARP APL software under license.
Other services including 2780/3780 Bisync support, remote printing, X.25 gateway and SDLC pipe lines were added in the 1978 to 1984 era.
There was no general purpose data transport facility until the introduction of Network Shared Variable Processor (NSVP) in 1984.
IPSANET allowed for the development of an early yet advanced e-mail service, 666 BOX, which also became a major product for some time, originally hosted on IPSA's system, and later sold to end users to run on their own machines.