Introduction

The first public videoconference was held in April 1930, between AT&T headquarters and their Bell Laboratory in New York City. [Rosen] Microphones and loudspeakers transmitted the audio while, under a blue light, their images were captured and transmitted as they looked into photoelectric cells. An article in the April 10 edition of the New York Daily Mirror described the audio as clear and the image under the blue light as inoffensive (a term commonly used for driver's license photos but not often heard today for videoconferencing!) It was at this time that the value of face-to-face conversation at a distance was expressed.

Shortly thereafter, The FCC was formed in 1933, when radio and television traffic began to collide. In 1934, the standards wars between companies began with the FCC intervening to establish hearings and approve standards. In 1941 the first analog standard for television, with 4.2 MHz of bandwidth (525 scan lines and 30 frames per second), was adopted. By the 1950's we had 83 channels covering the frequencies 54 to 890 MHz.

But it was thirty years after that first AT&T videoconference, before the first videoconferencing product was introduced on the market. In 1964, AT&T introduced its Picturephone at the New York City World's Fair. This system, marketed as an exclusive executive tool, required 1 MHz processing power (considered daunting at the time) and provided the first data-sharing feature. In 1971, the first transatlantic videoconference occurred between two Ericsson systems (a product named LME.) And some twenty years later, desktop videoconferencing clients became available.

In 1996, the first version of the ITU H.323 standard was approved, encompassing video conferencing over IP networks. Intel, PictureTel, and VTEL were some of the early desktop players. Others - Zydacron, VCON, Polycom, Tandberg - followed as the market grew and changed. That market is continuing to grow and change and H.323 arguably is still the predominant standard for videoconferencing over IP but other other standards are moving ahead. The Session Initiation Protocol (SIP) is maturing and several leading vendors such as RadVision, Wave3, Microsoft, and even Apple are delivering SIP tools in their product line. Applications from the academic and research community, such as VRVS and the AccessGrid, are also being used more and more by people outside of the original intended user groups. It is likely that all of the various technologies being used to enable virtual presence today will continue to change quite radically as we learn more about what we can and might do with virtual presence in the future.

Welcome to Version 4.1 of the ViDe Video Conferencing Cookbook. We are happy to bring you another update and continue evolving this resource in response to the interest and demand for balanced reference material on the implementation of IP video conferencing. If you are new to this subject and the Cookbook, we hope you find it easy to use and that the Cookbook helps ease your entry into a growing and most promising use of the Internet. If you've already read a previous version of this cookbook or if you are a veteran of videoconferencing, we hope that you find the new content here interesting and useful.

Preface
This section has been reviewed and updated as needed.

Uses of Videoconferencing
Uses, applications, and case studies have been pulled together into this section. The case studies have been updated to include projects on middleware and directories, MPEG in the classroom, satellite videoconferencing, K-12, and some data collaboration.

Popular Collaborative Technologies
We continue to cover H.323 but also take the opportunity to introduce several other technologies for videoconferencing. We've updated information on VRVS, Access Grid, MPEG and motion JPEG, as well as web clients. We've introduced SIP as the newest, popular kid on the block.

Emerging Collaborative Technologies
This section describes a few things we continue to track such as satellite videoconferencing and data collaboration. We include discussions of new work in middleware and we highlight some experimental systems that are in R&D today.

Basic Requirements for Successful Videoconferencing
Basic and add-on components are featured in this section. We also go over tips on selecting and tuning your PC. A new section on testing your system and the connection has been added.

Best Practices and Etiquette
Here we give tips on how to look and sound your best through technical discussions on the audio and video environments and the basic "rules of the road" when in a videoconference.

Practical Videoconferencing Examples
So you're wondering what these interfaces look like? Stop by here for a preview. We now include H.323, SIP, and some data collaboration examples.

Network Matters
This section describes the typical network connection needed for good videoconferencing. It includes a list of typical problems seen when the network connection is incorrectly configured or experiencing problems. Tips on who to talk to at your site and tools to monitor your connection are suggested. This version discusses firewall/NAT use and home networks using cable modem and DSL.

Advanced Components and Management
This section describes the complex equipment whose role includes multipoint conferencing, gatekeeper security, and signaling translation. This version includes a section on "Middleware for Videoconferencing". Good topics for new site administrators are here, such as profiling your users' needs and other deployment issues.

Related Topics
This section covers various peripheral but valuable topics such as developing a room for videoconferencing, multicast, and broadcasting and archiving videoconferences.

K-12 and Classroom Specific Needs
This is a new section that devotes significant attention to the K-12 environment and other classroom or teaching venues. Tips on engaging students are prominent along with guidelines and checklists for successful use in the classroom. The K-12 case studies give good examples of projects that bring interesting and fun resources into the classroom.

ViDe Favorite Recipes
Well, it *is* a cookbook...and our new contributors have added some tasty new dishes!

Glossary
Videoconferencing related terms.

Appendices
This section includes Standards specifications, cookbook references, listservs, and hotlists. The section on Vendor Relationships has also been moved here.

Use of This Material
Periodically we get requests to incorporate all or portions of the Cookbook into other publications. This section provides a copyright template and describes our reuse policy.