SIP Messages

SIP messages are the cornerstone of the Session Initiation Protocol (SIP), enabling the orchestration of communications within the SIP framework. These messages fall into two primary categories: Request Messages and Response Messages, each playing a pivotal role in the SIP signaling mechanism.

Together, these two types of messages afford granular control over communication sessions, facilitating intricate interactions and functionalities within the SIP protocol. Understanding the intricacies of these messages is critical to leveraging SIP's extensive capabilities in real-time communications scenarios. SIP methods, which are essentially the request commands, initiate actions between parties on a SIP network, managing the conduct of sessions or calls. These methods are integral part of SIP functionality and cover everything from the inception of sessions to their modification and eventual termination.

The RFC 3261 specification lays down the groundwork for SIP operations, describing the behavior, parameters, and expected responses for each method to ensure consistency and interoperability among SIP-enabled communication systems. For in-depth insights into specific methods and their implementations, RFC 3261 serves as the go-to reference.