Voice over IP Fundamentals, Second Edition

Chapter 11. H.323

H.323 is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T) specification for transmitting audio, video, and data across an Internet Protocol (IP) network, including the Internet. When compliant with H.323, vendors’ products and applications can communicate and interoperate with each other. The H.323 standard addresses call signaling and control, multimedia transport and control, and bandwidth control for point-to-point and multipoint conferences. The H series of recommendations also specifies H.320 for Integrated Services Digital Network (ISDN) and H.324 for plain old telephone service (POTS) as transport mechanisms.

Currently, H.323v5 (version 5) is considered the latest version as ratified ...