SIP Protocol Fundamentals Master the Session Initiation Protocol (SIP) for building VoIP applications, understanding SIP messages, methods, and call flows essential for real-time communications. Understanding SIP SIP is an application-layer signaling protocol defined in RFC 3261 for creating, modifying, and terminating sessions with one or more participants. SIP Message Structure When to Use This Skill Use sip-protocol-fundamentals when building VoIP applications with SIP signaling. Best Practices - Always include unique branch parameters in Via headers - Implement proper transaction timeout…