Use Zoiper 3.5 if you are on a legacy OS, a low-powered PC, or own a perpetual license. Use a modern client if you need encryption or video.
Modern VoIP apps (like Zoom, Teams, or modern Zoiper 5) can consume 200-400MB of RAM just to launch. Zoiper 3.5 runs comfortably in under 50MB of RAM. For legacy systems running Windows XP, Windows 7, or thin clients, this is a lifesaver. zoiper 3.5
Subject: VoIP Client Selection.