How Conferencing Works

By: Dave Roos
Face-to-face conferences aren't always viable.
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Whenever two or more people gather to share information, collaborate, brainstorm, argue, inform or train one another, that's called a conference.

Conferences can be face-to-face affairs. A salesman attends a trade show to pitch his product to hundreds of potential clients. The accounting department and the CFO sit around a big table and review the fourth-quarter numbers. A consultant flies around the country to train employees on a new software application.


The drawback is that these face-to-face meetings, presentations and training sessions aren't always financially viable. Many of today's companies compete in a global marketplace with offices around the world and clients from Moscow to Moscow (Idaho and Russia, that is).

Communication and technology advances have made it possible to recreate the impact and interactivity of real-world conferences without having to leave your desk.

But what is teleconferencing? How does videoconferencing work? And, what are Web seminars? Read on to find out.



A diagram of how a teleconferencing bridge works.

If you've ever made a three-way phone call, you've already teleconferenced. When we talk about teleconferencing, we're referring to conference calls, where small to very large groups of people can participate in, or at least listen to, the same phone conversation.

There are two general types of conference calls. MeetMe conferencing requires participants to call a special phone number on a given day and time and enter an access code to join the teleconference. Ad-hoc conferencing requires a moderator to call each of the attendees individually and connect them together.


Conference calls require something called a conference bridge, a special server that can receive and route up to thousands of calls at the same time. Larger companies might own their own conference bridge, but it's also possible to subscribe to an outside company to host your conference calls on their bridge.

The conference bridge then links to a private branch exchange (PBX) within the company. A PBX is a miniature switch that routes calls to all the different internal phone extensions in the company. This is especially important for in-house conference calls.

A new teleconferencing option is VoIP conferencing, in which phone calls are made over the Internet rather than traditional phone lines. If a company already contracts with a VoIP service provider, it can usually upgrade to have teleconferencing capability. VoIP phone calls are considerably cheaper than traditional calls and with the right Internet connection speed are similar in quality.

There are many companies that host teleconferences and also offer helpful Web tools and in-call features. Here are some common features of teleconferencing services:

  • Easy to e-mail or text message invitations to join the teleconference
  • Call recording
  • Audio control (mute or un-mute attendees)
  • In-call operators
  • Attendee polling
  • Handset controls using the * key

Teleconferencing has endless applications in the business world, from large corporate conference calls for shareholder earnings reports to four salesmen in four different cubicles discussing a new product.

Teleconferencing's advantages are that the technology is familiar to anyone who uses a phone, it's easy to set up, and it offers good audio interactivity for small groups. Its disadvantages are that it greatly limits collaboration and interaction for larger groups, and that audio-only presentations are often less engaging to attendees.

Read on to learn about Web conferences and Web seminars.


Web Conferences and Web Seminars

Web conferences let participants join in from anywhere.
Wesley Hitt/The Image Bank/Getty Images

Web conferences and Web seminars allow groups of people to collaborate online using special software or Web interfaces. The unique power of Web conferences and seminars is the ability to share desktops, documents and applications with all the attendees. The audio portion of Web conferences and seminars is either handled through a conference call or over the Internet through VoIP and special headsets.

Web conferences and seminars are organized a lot like MeetMe conference calls:


  • An organizer sends out e-mail or text message invitations to join the Web conference on a certain day and certain time.
  • The invitation includes a link to the conference and a password or access code to enter. If the invitation is accepted, a reminder is programmed into the attendee's calendar application.
  • Once all the attendees log on to the conference or seminar, a single presenter controls the meeting. As presenter, you can share your desktop and other documents and applications. You can also hand control over to the other attendees and let them present.

The difference between a Web conference and a Web seminar is the group size and the amount of interactivity in the meeting or presentation. Web conferences are for groups of 10 or fewer people where attendees all have the opportunity to speak and present in turn. Web seminars are for dozens or even thousands of attendees where only a few presenters or panelists have the power to speak and share documents.

Here are some of the common features of Web conference programs:

  • Using common applications like Microsoft Word, Microsoft PowerPoint and Adobe Flash Player, presenters can create dynamic graphic presentations enhanced by audio or even streaming video.
  • Has the ability to create e-mail invitations with easy-to-use templates. The software also has the ability to schedule event reminders and follow-up e-mails.
  • Desktop sharing allows the presenter to display everything that's on his computer to attendees in real time. They see exactly what he sees. The presenter can also hand control of his desktop to any of the other attendees. Or, by changing presenters, any of the other attendees can now share his desktop with the rest of the group.
  • Document sharing and application sharing work exactly the same way. Although it's more common in small Web conference settings, a presenter can hand control of an open document to one of the attendees, who can then edit or change the document remotely. It's also possible to share applications without even loading the software on each of the attendees' computers.
  • File transfer allows you to post documents for download either before, during or after an online presentation.
  • Audio control allows the presenter to mute or un-mute panelists and attendees as needed. For larger Web seminars, it's typical to mute all attendees.
  • Whiteboards are shared virtual workspaces where presenters can cut and paste documents, graphs and images. By sharing control of the whiteboard, presenters can draw, annotate and edit just like they were scrawling on a real-world whiteboard.
  • For greater interactivity, presenters can give attendees chat capability or the option of instant messaging questions to the presenters.
  • Most Web seminar software also includes tools to analyze the success of a presentation. Presenters can take advantage of real-time polls and attendee mood meters. Some programs include the ability to monitor users' desktop behavior to see if they become distracted from the presentation and begin working on other documents. And if so, the program can tell presenters when their attendees' attention drifted and how long it lasted.
  • Web seminars can also be recorded for later use in presentations or training sessions or downloaded for on-demand playback on the desktop.
  • Some Web seminar software includes built-in video capability to stream directly from a Webcam or digital video camera. There are also more expensive Web seminar services that help create professional-quality streaming or on-demand video presentations for large audiences. We'll explain more about how these Webcast services work in the next section.

Web conferences and seminars work because they are hosted on a server. Images from the presenter's computer are constantly uploaded to the server and continuously "served" to the attendees in a process much like streaming video. Attendees are able to share desktops, documents and applications because those files are temporarily "living" on the server where anyone with the right link and password can access them.

Web conferences and seminars have dozens of applications in the business and private sector: new product presentations, distance learning at colleges and universities, remote employee training, collaboration on editorial copy, legal documents, architectural drawings and more.

Web conferences and seminars are easy to set up and can increase collaboration for small groups and increase interactivity and general interest in larger groups. A potential disadvantage is that certain Web conferencing programs only work for Windows-based PCs.

Now let's talk about video conferencing and Webcasts.


Videoconferencing and Webcasts

A Webcam for a Webcast.
Photo courtesy

More and more Web conferencing services and software come with the ability to add video from a desktop webcam. This is the simplest form of videoconferencing, where the presenter appears on the screens of all the attendees in a small Webcam video window. For small groups, some software programs offer the "Brady Bunch" effect, in which all of the attendees appear on the screen in separate Webcam windows.

There is a difference, however, between this simple form of videoconferencing and what are known as webcasts. Webcasts are professional-quality online video presentations, usually for larger groups and with less interactivity between participants.


Here's how webcasts work:

  1. Video is shot on a digital video camera and can be either streamed live or recorded and edited for later broadcast.
  2. The video feed needs to be compressed into a digital code such as MPEG, Windows Media or Quicktime.
  3. The compressed signal is then encoded for transmissions and playback over an IP network.
  4. The video is ready to be watched online either as live streaming video or as an on-demand download.

There are a number of companies that offer videoconferencing software and services. Here are some of the more common features:

  • Off-site video compression and delivery
  • Invitation management, attendee polling, follow-up reports
  • Chat and text messaging for question and answer sessions
  • Professional video and editing services

On the webcam level, videoconferencing is useful for giving a face, literally, to a sales presentation or for demonstrating the physical features of a small product. Webcasts are useful for large, company-wide meetings, press conferences and public product announcements.

The chief advantage of videoconferencing is that audiences tend to absorb information better if they are both seeing and hearing it. A disadvantage is that interactivity is severely limited in very large video presentations.

Read on to find out about the future of conferencing.


Unified Communication Systems

Many people can participate in online or video conferences.
Thomas Northcut/Getty Images

Moving forward, we're going to see more and more companies offering a unified communication system. With the popularity of IP telephony on the rise, businesses can now access all of the old and new means of communication through one supplier and one simplified software package or Web interface.

There are going to be several big companies vying for these all-in-one corporate accounts. Cisco Systems recently bought WebEx, the market leader in Web conferencing services. And Google recently announced a partnership with Avaya, a leading IP telephony and communications company.


Unified communication systems will be attractive to businesses because it will simplify billing and systems administration and hopefully lower the overall costs of conferencing by combining disparate services through one vendor.

For lots more information about conferencing and related topics, check out the links on the next page.