Wikipedia
SVOPC
SVOPC (Sinusoidal Voice Over Packet Coder) is a compression method for audio which is used by VOIP applications. It is a lossy speech compression codec designed specifically towards communication channels suffering from packet loss. It uses more bandwidth than best bandwidth-optimised codecs, but it is packet loss resistant instead.
Skype Limited developed a codec called 'SVOPC' for Skype. It was first used in Skype 3.2 beta 53, released on March 28, 2007. Starting with Skype 4.0, SVOPC is replaced by SILK.