IMS-Specific SIP Header Fields

IMS (IP Multimedia Subsystem) is an architectural framework for delivering IP multimedia services. It was initially designed by the 3rd Generation Partnership Project (3GPP) as part of the evolution of mobile telecommunications networks towards 3G and beyond, but its use has expanded to any network that delivers IP multimedia to end-users. IMS enables the convergence of data, voice, video, and mobile network technology over an IP-based infrastructure, making it possible to provide a wide range of telecommunications services across both wireless and fixed networking environments. 

IMS facilitates the integration and delivery of voice, video, messaging, data, and web-based services, enabling rich multimedia experiences for users. Uses SIP for session management, enabling the establishment, modification, and termination of sessions with one or more participants.