How does IP video conferencing work?
Like other video conferencing technologies, IP video uses cameras and microphones to capture the video and audio signals produced at each site. The heart of the IP video system is a specialized piece of equipment called a codec, which stands for COder/DECoder. The codec acts something like a television. Rather than picking up broadcast signals from the air and turning those signals into audio and video, a codec receives its signal in data format over the Internet and displays it in viewable form on a monitor. A computer may be an integrated part of the codec, or the codec may be a separate piece of hardware that is hooked up to an existing computer. Encoded video data are sent over the Internet to participating sites, where receiving systems decode the data for viewing by the other conference participants. A new capability called Quality of Service ensures that regardless of the amount of Internet traffic your location is experiencing, your video will never suffer.
The Indiana Telecommunications Network (ITN) has instituted a Dial Plan, a standardized format for assigning an identity to each user. Much the same way every computer accessing the Internet needs its own unique identifier (IP address) to differentiate it from all the other computers, each piece of IP video equipment needs to be recognized individually. The Dial Plan assigns individual numbers, much like telephone numbers, to the equipment. Without that unique number, an end-user could decide to have a new phone number every day or decide to dial a number that does not belong to the end-user that is being called, thus making it very difficult for one person to reach another.
Coupled with the Dial Plan is Directory Service, which is essentially a virtual phone book containing information about every available IP video unit on the network. Whether they are active or not, each registered IP video unit will have its unique number stored in the Directory Service database. Without such a service, each user would have to contact the person they want to reach to obtain information about how to connect with them. After the exchange of information, one party could call the other. This process would have to be repeated for every desired endpoint. Eventually each IP video user would have their own personal directory, which would always be incomplete and require frequent updates. A centralized directory service solves this problem by having everyone on the network register with it. The administrator enters the appropriate information for each endpoint, which then becomes accessible to all users on the network.
Click to Meet (CTM) is the interface for scheduling calls and programming over IP video. Sites are registered in the CTM database through the process of endpoint certification. CTM utilizes a Web interface, and acts as the interface of the virtual phone book. CTM can tell when an endpoint is or is not available for a call, and can then make the connection by having the user simply select the desired endpoint. For third-party programming such as Vision Athena, you will follow the existing scheduling procedures for that content provider.
Because of the ability to bridge different sources of video, you will have many options for using IP video. Bridging is the means by which different types of video conferencing technologies are interconnected so that they are all compatible with each other. This is performed by IHETS video engineers.
Finally, the ITN has enabled Quality of Service (QoS), a set of techniques to manage the data traffic on the ITN that ensures the quality of IP video transmission. QoS allocates a set amount of bandwidth to video calls, and forces other data traffic to flow around it. This technique eliminates freezing or jumpy video and dropped video calls by setting precedence for video data information over other types of data.
