JAIN-SIP, or JSIP, is a Java specification for SIP Signaling.
Overview
The Java APIs for Integrated Networks (JAIN) is a JCP work group managing telecommunication standards. Session Initiation Protocol (SIP) is a standard communication protocol. Java and SIP together create the JAIN SIP API, a standard and powerful API for telecommunications. This idea started in 1999 with JSR 32. The reference implementation is open source, very stable, and very widely used. This API is frequently (but not necessarily) used for client-side application development. Other container-based technologies, like SIP Servlets, are simpler to use for server-side development.
Useful Links
JAIN-SIP homepage