Not all forms of internet access were based on dial-up in 1998. ISDN was on use in some places, but it was never cheap enough as a retail service to take over as the ubiquitous access method for the Internet. There were also access services based on Frame Relay, X.25 and various forms of digital data services. At the high end of the speed spectrum there were T-1 access circuits with 1.5Mbps clocking, and T-3 circuits clocked at 45Mbps.
If you were an ISP you leased circuits from a telco. In 1998 the ISP industry was undergoing a general transition of their trunk IP infrastructure from T-1 circuits to T-3 circuits. While it was not going to stop here, squeezing even more capacity from the network was now proving to be a challenge. 622Mbps IP circuits were being deployed, although many of these were constructed using 155Mbps ATM circuits using router load balancing to share the IP load over four of these circuits in parallel. Gigabit circuits were just around the corner, and the initial exercises of running IP over 2.5Gbps SDH circuits were being undertaken in 1998.
