VoIP can offer an alternative to the PSTN or cell phone whenever there is a problem with either service. Pretend your drunken neighbor just backed out of his driveway and killed the phone pole – no one is going to have telephone service until the phone company comes, assesses the damages and gets a new pole set in place and re-hooks everything. That could take days at least to repair. If you are in an area that your cell phone does not work as well, how will you ever make a single phone call? Now you have the option of going to your computer and making your calls right from there.