WORKSTATION-BASED VTC AND WHITEBOARD FOR DEPLOYMENT OVER THE DSI AND GCCS LES

DRAFT - DECEMBER 30, 1994
THE MITRE CORPORATION
AUTHORS:

Christopher O'Donnell

Charles King

Alok Nigam

Elden George - Space Applications Corporation


EXECUTIVE SUMMARY

By request of the Advanced Information Technology Services Joint Program Office (AITS-JPO), MITRE conducted a review of available desktop commercial off-the-shelf (COTS) products that support collaborative computing (shared whiteboards and desktop video teleconferencing (VTC)) over packet networks. The primary review criteria were interoperability between products, support of standards-based VTC, and availability on UNIX platforms. MITRE also conducted demonstrations of UNIX-based VTC capabilities to AITS-JPO representatives.

Communications support for video teleconferencing requires the following three characteristics: (1) guaranteed throughput to ensure integrity of motion video and intelligible audio; (2) fast data forwarding to assure minimum latency (the time from video capture to video display); and (3) multiple data streams to permit more than one simultaneous VTC.

Our research indicated that the use of real-time face-to-face video over local area networks (LANs) will remain an immature technology for at least the next two years. Some technologists suggest that this technology will not mature until around the year 2000. Reasons for this immaturity include both standards issues and network technology limitations. These issues suggest that interoperability between different manufacturers' products will not be achievable in the near term, and thus, users must deploy proprietary products, and expect to upgrade to an interoperable standards-based capability in the future.

Only one packet-network COTS VTC product was identified during this review that offers standards-based (H.261) desktop VTC on UNIX platforms. There was limited availability of standards-based desktop VTC on personal computers (PCs) over packet networks. As discussed in this report, there are some VTC products that have implemented a portion of the H.320 international standard that provide compressed video and audio over LANs using Internet Protocols without use of special interface units. However, these implementations still provide VTC only among users of a single manufacturer's products, with no interoperability to other vendors' products.

Based on our evaluation criteria, the leading COTS product for UNIX-based desktop VTC is InSoftõs Communique, which supports a proprietary approach to VTC over packet networks. This product was evaluated in MITREõs labs. VTC was conducted between two workstations at data rates that varied between 800 kilobits per second (Kbps), supporting a frame rate of 27 frames per second, to 150 Kbps, supporting a frame rate of approximately 4 frames per second. Insoft has indicated their intent to move to standards-based VTC once formatting standards for communication packets have been ratified by the International Telecommunications Union (ITU) committee.

The InSoft product offers a capability for near-term support of collaborative computing (video, whiteboard, and sharing of applications). However, the user acceptance of the current product, using its proprietary capability at a throttled speed, is uncertain. Lost or delayed communication packets must be disregarded, video may freeze, and short phrases of audio may be lost. In addition, product robustness and interoperability issues identified by current users have not been resolved. For this reason, it is recommended that tests be conducted using InSoftõs Communique product in a user environment between two or more DSI nodes. If the DSI tests are satisfactory, a limited initial deployment is suggested with user acceptance to drive expanded use.

SECTION 1 - Introduction
SECTION 2 - Standards Based VTC
SECTION 3 - Product Evaluations
SECTION 4 - Issues
SECTION 5 - Conclusions and Recommendations
Appendix A - H.320 Standard
Appendix B - Products and Vendors
Glossary