 The first is the ability for users who have call waiting to put their dial-up Internet connection on hold for extended periods of time while they answer a call.The second feature is the ability to quickly connect to one's ISP, achieved by remembering the analog and digital characteristics of the telephone line, and using this saved information when reconnecting.As telephone-based 56k modems began losing popularity, some Internet service providers such as Netzero/Juno, Netscape, and others started using pre-compression to increase the throughput and maintain their customer base.