My first net connection was using slirp via a shell account. Slirp was a CSLIP emulator that ran in user space on the shell box on the remote side.

Back in those days multi user shell machines were quite common and some of the first ISPs offered Internet access that way.

Mine was an ISP called Internet Access Cincinnati that gave each user shell on a Sun Sparc 10 running SunOS (pre-Solaris). You also got POP e-mail and a -username home folder accessible via web.