The full form of SIP can vary depending on the context. Here are a few common interpretations:
Session Initiation Protocol – A signaling protocol used for initiating, maintaining, and terminating real-time sessions that involve video, voice, messaging, and other communications between endpoints.
Systematic Investment Plan – A method of investing in mutual funds where an investor contributes a fixed amount regularly (monthly, quarterly, etc.) instead of a lump sum.
SIP (SIP Trunking) – A method used in voice over IP (VoIP) that allows businesses to connect their phone systems to the public telephone network using the Internet.
If you have a specific context in mind, please let me know!