The primary digital communication standard used in VoIP is Session Initiation Protocol (SIP). SIP is crucial for establishing, maintaining, and terminating voice and video calls over the internet, enabling seamless communication services. It manages the signaling process, allowing endpoints to communicate effectively. This protocol, designed for flexibility and interoperability, integrates with various multimedia formats, enhancing the overall user experience. The rise of VoIP and SIP has transformed traditional telephony by providing cost-effective solutions and greater functionality, such as video conferencing and instant messaging.