Videoconferencing

The Texas State Library and Archives Commission regularly utilizes videoconferencing technology for meetings and continuing education workshops for librarians. Through a series of frequently asked questions, this page provides more information about videoconferencing technology.

Frequently Asked Questions


What is videoconferencing?

Videoconferencing is a form of communication that allows real-time interaction between people at two or more physical locations – that is, it allows for two-way video and two-way audio interaction through the transfer of video and audio packets via telecommunications. Some types of videoconferencing equipment allows users the ability to send and/or share data during the videoconference.

How is videoconferencing different from teleconferencing?

Videoconferencing should not be confused with satellite teleconferencing as the two involve different transmission media and different modes of interaction. The most important distinction to remember between the two is that videoconferencing allows for realtime interaction among pariticipants while teleconferencing allows for limited interaction. For more detailed information about teleconferencing, please visit the satellite teleconferencing page.

How does videoconferencing work?

Videoconferencing equipment allows audio and video (and perhaps data) packets to be exchanged through telecommunications lines between two or more sites. Videoconferencing can occur over ISDN lines or IP-based lines. ISDN-based videoconferencing conforms to the H.320 standard and IP-based videoconferencing conforms to the H.323 standard. If T1 lines are used for the videoconferencing network, they have the disadvantage of being dedicated to and from fixed points, whereas ISDN lines can dial in to other networks. While it is true that an IP-based network could videoconference over the public Internet, there is no guaranteed quality of service on the public Internet so videoconference quality may be inconsistent. One main benefit of IP-based videoconferencing are fixed monthly costs, as opposed to per minute long distance fees incurred by the use of ISDN lines.

Theoretically, any two videoconferencing systems with the same standard (regardless of brand/manufacturer) should be able to conduct a basic videoconference. If videoconferencing systems with opposing standards would like to videoconference with each other, another piece of equipment called a gateway must be used. In order for a videoconference to occur between more than two sites at one time, a piece of equipment called a Multipoint Control Unit (also known as a bridge or an MCU) must be used.

What is a point-to-point videoconference? What is a multipoint videoconference?

A videoconference between two sites is called a point-to-point videoconference. A videoconference between more than two sites is called a multipoint videoconference. More information about multipoint conferences can be found on our Multipoint Videoconferences page.

Do you have tips for those participating in a videoconference?

Yes, a list of tips for videoconference participants is available on our Videoconferencing Tips page.

How much bandwidth is required for videoconferencing?

The quality of a videoconference is directly affected by the amount of bandwidth allocated to the call. Most videoconferencing experts recommend that you calculate the amount of bandwidth you anticipate needing and then acquire twice that amount to account for overhead. A tolerable yet choppy videoconference call could conceivably take place at 128k while business quality videoconferencing calls are placed at 384k.Some professions require even higher quality videoconferencing – medical and scientific videoconferencing calls are typically placed at speeds of 512k or higher.

What is room-based videoconferencing? Desktop-based videoconferencing?

Traditionally, videoconferencing has been room-based -- special videoconferencing rooms have been wired to house videoconferencing systems designed for group videoconferencing. Room-based videoconferencing equipment typically resembles an elaborate television / monitor setup with one or more cameras. Additional equipment which may be found with the videoconferencing equipment are speakers, microphones, personal computers, whiteboards and objects that resemble overhead projectors which are called document cameras.

With the advancement of video and audio transmission over IP, videoconferencing from one PC desktop to another has become possible -- hence the term "desktop-based" videoconferencing. Desktop videoconferencing is now becoming widely used through company Intranets, home consumers and in some live components of online/Web-based learning segments.

How does the Texas State Library use videoconferencing?

The Texas State Library regularly utilizes videoconferencing technology to conduct or attend meetings and continuing education workshops. Currently, due to the renovation of the Lorenzo de Zavala State Archives and Library Building, the Texas State Library and Archives Commission has suspended videoconferencing. New developments will be posted as they become available on the Texas Library Videoconferencing Network page.

Are there other statewide videoconferencing networks in Texas?

Yes, two well-known statewide videoconferencing networks are the Texas Education Telecommunication Network (TETN) and TTVN (the wide area data and video network for institutions of the Texas A&M University System).

Do you have information for someone thinking about buying videoconferencing equipment?

If you are thinking about buying videoconferencing equipment, you should consider your primary purpose in obtaining such equipment. If you are wanting videoconferencing equipment because you would like to participate in educational programs, you should identify the content providers which interest you the most and determine what the costs and requirements will be to videoconference with them. As stated previously, the videoconferencing standard you use in conjunction with your videoconferencing equipment will also be an important factor -- if you have an IP-based videoconferencing system in place and you would like to videoconference with someone who has an ISDN-based system, one of you will have to have access to a gateway which will make your connection possible. Another important factor to consider regarding the two telecommunications standards is the fact that with IP-based videoconferencing, your costs are fixed costs -- you pay a flat monthly rate and can videoconference to your heart's content with any other IP-based videoconferencing system. (It is important to note, however, that videoconferencing over the public Internet with another IP-based system does not guarantee a consistent quality of service. IP-based videoconferencing works best over LANs and WANs because bandwidth can be dedicated and controlled.) While ISDN-based videoconferencing is traditionally more reliable, costs can become prohibitive since you are charged for the use of your ISDN lines by the minute. These are just a few of the things you will need to consider if you are thinking of purchasing videoconferencing equipment. See our recommended links for more information about videoconferencing.

Do you have a list of videoconferencing equipment manufacturers?

Yes. The following is a list of some of the main videoconferencing equipment manufacturers. (It is important to note that some manufacturers do not sell directly to the consumer -- their equipment must be purchased through a vendor. In addition to selling equipment, oftentimes vendors can provide added videoconferencing services such as bridging services and telecommunications.)

Do you have a list of videoconferencing program providers for general topics?

The following are links to videoconferencing program providers and/or provider directories for general programs:

Do you have a list of videoconferencing program providers for library-related topics?

Yes, the Texas State Library's "Distance Learning in Libraries" publication contains a section of videoconferencing program providers of library-related topics.

Where can I go for training on videoconferencing techniques?

The University of Wisconsin's Distance Education Clearinghouse has some information on training programs. In Texas, one entity offering videoconferencing training is the: The Center for Distance Learning Research.

Where can I find a videoconferencing glossary?

A couple of recommended videoconferencing glossaries are: AT&T Knowledge Network Explorer Glossary and VCON's Videoconferencing Glossary.

Where can I go for more information about videoconferencing?

Where can I find information about libraries/librarianship and videoconferencing?

The Texas State Library online resource "Distance learning in libraries" contains general information about distance learning and libraries as well as specific information about online learning and libraries.

Who can I contact for more information at the Texas State Library?

Please direct videoconferencing questions to:

Naomi DiTullio, Distance Learning Consultant, Library Development Division


512-936-2586 or naomi.ditullio@tsl.texas.gov.

Page last modified: January 25, 2011