Today your dialup software is located in your windows software it's called HyperTerm, basically it's similiar to the applications used back in the day with bulletin board systems.
Some of the orginal applications where termed Telix, Procomm to name a few.
Orginally the user was in a Dos enviroment and then loaded the application, they had be familiar with irq's, modem strings to name a few. The application basically stored phone numbers and names of bulletin board systems and the user would then dial out. The applications contained protocols like Zmodem, Xmodem to name a few allowing the user to download applications from the bulletin board systems.
This is a screen photo of the orginal Telix Dos Communications
Software Application, Telix was on of the top 5 shareware products