NSV are only supported in version 2.2.0 and newer.

Icecast requires external programs, called "source clients", to originate the streams, and the Icecast project includes a source client program known as IceS. The source runs typically in the place where the audio is generated (e.g., a studio) and the Icecast server where a high-bandwidth connection is available (e.g., a colocation centre).