The telecommunications standards are established through the International Telecommunications Union, ITU. The ITU is based in Geneva Switzerland, and its membership includes 192 Member States and more than 700 Sector Members and Associates. The ITU is a 145 year institution and the agency for information and communication technology issues. They coordinate the shared global use of the radio spectrum and promote international cooperation in assigning satellite orbits. Part of the ITU’s mandate includes improving telecommunications infrastructure and foster seamless interconnection of communication systems. In this effort the ITU develops and establishes worldwide communication standards. This is critical to videoconferencing technology as these standards allow all manufactures to develop products that all work together and compete on an even playing field.
This first critical standard affecting videoconferencing was H.320 through an ISDN, Integrated Services Digital Network. This standard allowed anybody to connect on the ISDN network provided through the phone companies. The great thing about this standard is that it was reliable and you connected seamlessly to any other system by dialing a 10 digit phone number in the CODEC or video conferencing system. Also, the ISDN circuits were dedicated to the CODEC, thus quality of the calls were maintained.
This first standard, H.320, had a major impact on the industry. Cost went down and end users could pick and choose vendors without worrying about connecting to other systems — Also the performance of the equipment improved. The downsides of this standard through the ISDN network are: high long distance charges; relatively high bandwidth cost; high international tariff fees. Also International calls are difficult to place without and International long distance carrier. At the time these were minor issues as the ease of use and lower cost of equipment created a tangible return on investment.
The H.320 standard over ISDN was replaced by H.323 / IP Internet Protocol. The advantages with H.323 are: no long distance charges; seamless International calls with no International LD carrier; and much lower cost of bandwidth. Additionally more than 90% of the worldwide video conferencing endpoints use H.323. Another newer video conferencing standard is SIP / Session Initiation Protocol. This is a more open standard than H.323 and will allow more interoperability among manufacturer end points. SIP is predominant in VoIP, voice over IP, however not ubiquitous in videoconferencing – yet. Most new videoconferencing systems accommodate both the H.323 and SIP standards.
J.W. Hornyak Videoconferencing & Telecommunications
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