Videoconferencing
Overview
Videoconferencing technology offers exciting possibilities for the university community. When properly executed, it can enhance collaboration, facilitate teambuilding and personalize relationships with remote individuals and groups. Because of the potential that videoconferencing offers for enhancing the educational experience, there is a great deal of interest in what capabilities are currently available.
Three new room based systems have been deployed at the Mid-town campus in the following locations:
- Old Main – Rm 304
- Science Building – Rm 125
- Science Building - Rm 135
Given the current state of technology, University Computing can only support large format videoconferencing when ISDN connections can be established between participants. The requestor is responsible to verify that the appropriate connectivity is available prior to scheduling a videoconference. UC will be happy to answer any questions or provide any assistance necessary to facilitate a videoconference.
University Computing continues to stay abreast of technical developments and will investigate any new technology that might make IP technology more effective for this application.
Video Technology
Videoconferencing applications and hardware generally target three specific audiences; Click on the attached section for a description of elements involved in provisioning each system type.
1. DESKTOP SYSTEMS 
1. DESKTOP SYSTEMS 
Target Audience – 1 to 3 users
Required hardware/software - PC, video conferencing software, webcam, speakers and microphone or a headset.
Network Technology : TCP/IP Bandwidth Required: Low
Comments: Desktop videoconferencing is the most widely deployed and least technically challenging video conferencing application. Because only a small, low quality video image is displayed on the desktop and is refreshed at a relatively slow rate, the bandwidth requirements for this application are modest. At least one desktop application has the ability to function successfully across existing firewalls which further simplifies use of the application.
University Computing Position: UC has not standardized on a specific product in this area but is aware that Skype functions successfully in our environment, both to locations within and external to the university.
2. PORTABLE SYSTEMS
2. PORTABLE SYSTEMS
Target Audience – 4 to 10 users
Required hardware/software – Application specific hardware, software, high quality video camera, sound system and large format monitor. Generally provided as a complete system by a vendor specializing in videoconferencing technology.
Network Technology: TCP/IP or ISDN Bandwidth Required: High
Comments: Uses equipment comparable to a room system, but optimized for portability. Generally mounted on a cart so it can be moved easily. Portable Systems can provide video and audio quality and sophistication near that of a room system without requiring that a room be dedicated to the application. The overall quality of the videoconference will vary based on the characteristics of the room being used, including the lighting, room acoustics, background noise, furniture arrangement, etc.
University Computing Position: UC has examined the available equipment options but has not had sufficient interest among the university community to pursue acquiring a portable system at this time.
3. ROOM SYSTEMS
3. ROOM SYSTEMS
Target Audience – 10 plus users
Required hardware/software – Purpose built hardware, software, multiple high quality video cameras, sound system and one or more large format monitors. Generally provided as a complete system by a vendor specializing in videoconferencing technology.
Network Technology: ISDN or TCP/IP Bandwidth Required: High
Comments: The most sophisticated and complex videoconferencing application. It is characterized by a purpose built room designed to optimize the videoconference experience including lighting, acoustics, furniture design and arrangement as well as monitor, camera and microphone placement. When properly implemented this technology can rival a face to face meeting.
University Computing Position: UC has deployed three new room based systems; both systems are capable of supporting either ISDN or IP transmission. Based on the current state of technology on the public Internet, IP transmission is not supported for large format video conferencing. Please refer to the attached Network Technology overview
for a more detailed explanation of the technical issues involved.
Network Technology
At present, two different network technologies are used to provide connectivity for video conferencing. The following overview highlights the strengths and weaknesses of both technologies as a basis for understanding UC policy.
1. ISDN (Integrated Services Digital Network)
1. ISDN (Integrated Services Digital Network)
A decade-plus old circuit based technology used to establish point to point and point to multipoint videoconferences. The basic unit of ISDN technology is a 64k/sec digital channel referred to as a bearer or ‘B’ channel. In order to provide the bandwidth required for high quality videoconferencing (384K/sec), multiple B channels (6 x 64K) are established and bonded together for the duration of the conference. While the individual channels are subject to impairments that may impact service during a videoconference, this is a mature technology that provides a dedicated path not generally subject to interruption or change for the duration of a videoconference. This characteristic makes it well suited for high bandwidth video conferencing. The disadvantages are that connection costs are relatively expensive and ISDN service is not available in all parts of the world.
2. TCP/IP (Transmission Control Protocol/Internet Protocol) aka IP
2. TCP/IP (Transmission Control Protocol/Internet Protocol) aka IP
TCP/IP is the suite of protocols that has given rise to the Internet. It is robust and versatile packet based technology, which transmits information packet by packet over the best available route. It has the ability to identify and correct errors and then reassemble data that has arrived at varying times via different routes. It is the protocol of choice for data transmission and is increasingly being used for virtually all applications that require transmission over a network. Because TCP/IP network connectivity is ubiquitous and relatively inexpensive in comparison to dedicated circuits, there is significant interest in employing it for video transmission.
While TCP/IP is ideal for data transmission, the mechanisms that make it robust, also make it less than ideal for videoconferencing for the following reasons:
Videoconferencing is a real time application. Any errors or retransmissions, changes in data rate, available bandwidth or the physical path that the data traverses will result in delay or alteration of the video signal. While this is a relatively minor problem for data (e-mail, bulk files, etc.), it is disastrous for real time applications such as video or voice. Because large format videoconferencing (portable or room systems) requires large amounts of bandwidth (typically 384k) to function correctly, it is even more prone to minor impairments or variations in network bandwidth than desktop based video conferencing applications. The effect is that both the video and accompanying voice signal quickly become unusable. In addition to the problems caused by the characteristics of IP data transmission, network firewalls commonly deployed by individuals and organizations to protect their internal networks may require modification to allow IP based video to work successfully.
Technological enhancements are available to make IP networks behave like circuit based networks when used for videoconferencing. Additions to basic IP technology including MPLS, H.323, etc, provide a continuous transmission path and negotiate connectivity through firewalls. These technologies are ideal for corporate and private networks where the entire network is under control of single or cooperative entities. Unfortunately, the public Internet does not currently employ these types of enhancements so video transmission is a hit or miss proposition that will vary based on time of day, amount of traffic on the network, etc. The exposure to impairments generally increases as the distance between the conference locations increases or national boundaries are crossed, due to the number of different network elements that the signal will traverse.
