The official Zoiper download page (www.zoiper.com) only provides the latest installer. If you attempt to access www.zoiper.com/download/zoiper3.15 , you will be redirected to version 5+.
: Support for audio calls, video calls (H.264, VP8), instant messaging, and fax. Business Functionality Zoiper 3.15 Download--
Zoiper 3.15 is an older version of the popular VoIP softphone software used for SIP, IAX, and XMPP communications. The official Zoiper download page (www
Download Zoiper 3, a free VoIP softphone. Zoiper 3 Providers. video calls (H.264