H.323 is a data over IP standard introduced by the International Telecommunication Union Standardization Sector (ITU-T). As you can see, this standardization body uses letters to define the scope based on many criteria, listed here:
- H: For audiovisual and multimedia systems
- G: For transmission systems and media
- Q: For switching and signaling
- T: For terminals for telematic services
H.323 is one of the oldest packet-based communication systems protocols. Thus, this protocol is stable. The current version is v6. It is well used by many vendors in many products, such as Cisco call manager, NetMeeting, and RadVision.
H.323 uses many types of devices:
- Terminals: These are user devices such as IP phones and videoconferencing systems.
