What is H.323?

H.323 is a protocol suite developed by the ITU (International Telecommunication Union) that facilitates voice, video, and data communication over IP networks. It defines standards for call signaling, media exchange, and session control, making it one of the earliest protocols used in VoIP systems. H.323 supports interoperability between different communication devices and networks, enabling seamless integration of VoIP, video conferencing, and other multimedia applications. While SIP (Session Initiation Protocol) has become more popular due to its simplicity and flexibility, H.323 is still used in legacy systems and certain enterprise environments. It includes components like Gatekeepers, Multipoint Control Units (MCUs), and Terminals to manage sessions and maintain call quality. Despite being overshadowed by SIP, H.323 remains relevant in specific scenarios where established infrastructure relies on this protocol.