An apparatus to provide audio-visual communications across Local Area Networks (LAN) had been successfully handled by H.323 at a time when a broader arena in the transportation of multimedia applications was beginning to develop. The success of H.323 was acknowledged by the International Telecommunications Union (ITU-T ) when H.323 was introduced to meet increasing demands being created by the development and increased use of VoIP. In addition to its ready availability H.323 also provided supplementary services required to resolve future commercial communication activities. H.323 was the first VoIP standard to adopt the Internet Engineering Task Force (IETF) standard Real Time Protocol (RTP) to send audio and video over IP networks.
Based on the ISDN.93 1, H.323 possesses an ability to operate between IP and ISDN which helped it ease the introduction of IP Telephony into existing networks of ISDN based PBX systems. In the way that standard telephony is able to communicate across international borders via different machines so H.323 allows for interconnectivity between computers which might otherwise be unable to interact. H.323 accomplishes this by selecting appropriate mechanisms by which audio and video information is passed. H.323 advantages in this scope of activity include an ability to handle data in conjunction with T.120 data communications and conferencing or to do so separately.
Additionally other significant H.323 advantages include no restriction relating to the type of platform H.323 will operate on simply because H.323 has been developed by several manufacturers that made certain interoperability was a feature of the system. Through H.323 users can select the most appropriate codecs that support their computers and network selections. Microsoft’s NetMeeting utilizes audio and video conferencing processes conceived in the H.323 system that allows NetMeeting to function with other H.323 standards-based products.
H.323 product interoperability is calculated using the following categories of scale: a) Call signaling and control — a mechanism that establishes third-party acceptance using the same codecs or that an appropriate set of codecs can be used; b) Audio and Video streaming — a mechanism that identifies when interoperability issues may arise; c) Audio and video codec compatibility — a mechanism that examines third-party products to ensure compatible codecs are installed. Audio and video codecs present the audio and video information as a compressed package to be sent over the network. H.323 support amounts to the options it makes available to handle the audio and video coding.
In relation to data communications H.323 makes a provision for using T.120 as the mechanism by which it packages and sends data. File transfer and program sharing data use T. 120 support to operate in conjunction with H.323 connections.
Through the use of the H.323 protocols NetMeeting users are able to establish and maintain both audio and video connections to other compatible audio or video clients. In addition it seems highly probable that improved security and interoperability in relation to streaming media servers will appear in the near future. H.323 does not appear to have peaked as it continues to provide the necessary support for audio and video communications while at the same time possessing further development potential.