Basic Requirements for Successful Videoconferencing
ViDe Videoconferencing Cookbook
Tips for Selecting and Tuning your PC
Once you understand the basic components used in videoconferencing,
selecting and upgrading your workstation or laptop becomes the next important
step. For videoconferencing this depends
on the following factors:
- Operating system
- Videoconferencing end station
- Other applications you plan to support on the same system
- Processor power and memory
- Processor load from existing applications
Your choice of videoconferencing end station will be dependent on what operating
system platform the application is developed for, and what operating system
you are familiar with and comfortable using. Consider also the intended use
for this machine do you plan to do person-to-person conferencing? Will
your monitor's screen be required to support a display of multiple
users? There are many solutions available for PC users and now several exist
for Apple OS X users, but the market is still short on Unix solutions.
Types of desktop conferencing solution:
Video Appliance (USB connected)
PCI based solution (internal hardware codec)
Software (generic camera, microphone and sound card)
Be wary of over subscribing your processor with applications other than the
videoconferencing application. The need to do data sharing, and the applications
that are required to support the shared data, must be factored in when selecting
an endstation system. Knowing the impact of a personal videoconferencing solution
on your desktop requires careful review of product specification, including
application interactions and interoperability issues.
Become familiar with the vendor Web sites as you are shopping around. Find
the product descriptions and support pages. These will typically contain datasheets
(often pdf's) and/or system requirement sections. If you have questions about
any of the requirements or client specifications, you can email those questions
right from their site as well. Vendor representatives are happy to assist
In the meantime, we'll start you out with a general idea of what to expect.
Examples of PC system requirements to support videoconferencing applications
Assumptions for this type of solution:
- Appliance will handle all compression and decompression.
- Appliance is USB connected.
- Appliance may or may not have embedded microphone with echo cancellation.
- PC is already provisioned to support the OS platform requirements
- USB port
- Windows 2000, ME, XP, or 98, Second Edition (some include USB drivers
- 400+ MHz Pentium-class processor
- 128+ MB RAM and 8 MB video memory (64 MB RAM and 2-4 MB video memory
for Windows 98)
- 250MB available hard disk space
- SVGA display (800x600) 16-bit color or higher
- 1) headset/handset or 2) microphone and internal/external speakers
- user interface and application sharing may require specific software:
- Internet Explorer 6.0 or later
- Media Player 7.1 or later
- DirectX 8.1 or later
- Microsoft NetMeeting 3.01 or later
PCI based solution
Assumptions for this type of solution:
- PCI card/codec board will handle all compression and decompression
- Card is used in conjunction with vendor provided software
- The system is single processor running a single processor kernel
- 1 PCI slot
- Windows NT, 98, 2000, ME, XP
- 300+ MHz or higher Pentium PC
- 64+ MB RAM and 2 MB video memory
- 100 MB available hard disk space
- SVGA display
- camera, handset, microphone and/or speakers are generally included
Software solution (generic camera, microphone and sound card)
- 800+ MHz Intel Pentium III or
AMD Athlon, 500+ MHz Apple G4
- Windows 2000, ME, XP, Apple OS X 10.2 or 10.3, or Red Hat 9.0
or SuSe 9.0 and up (check client specifications for platforms supported.)
- 128-256 Mbytes RAM for 2000, ME, XP; 256 Mbytes RAM for OS
- Available USB and/or Firewire ports (Apple video only via Firewire)
- CD-ROM drive
- Display adapter capable of 16-bit color at 800x600; some require VGA
card and memory with DirectX and while others support a wider variety or
alternate list of video cards
- Sound Blaster or other Windows-compatible sound card and a microphone
are required for videoconferencing (sold separately); standard Apple audio
device (though iRez ClearMic and external speakers work nicely via line-in
- Live videoconferencing is possible with a number of third-party applications
- Windows: Wave3 Software's Session, Marratech Pro, VCON vPoint, RadVision
eConf, Yahoo! Messenger, CUSeeMe, OpenH323's OpenPhone, Web Clients,
and MSN Messenger
- Apple OS X: Wave3 Software's Session, Marratech, Pro, Apple's iChat
- Linux - Marratech Pro, OpenH323's OhPhone, OpenGK, and OpenMCU
Additional things to consider
- stand alone microphone or microphone/speaker systems may need to support
- handsets and headsets are available with telephone, USB, or line-in audio
connections so be sure to purchase the one appropriate to your end station
PC/Mac has the appropriate connection capabilities
Questions to ask yourself (or your system administrator):
Does the system configuration for my PC really matter?
The videoconferencing components are housed inside or along side a desktop
computer, laptop, or workstation. If the computer system is not powerful
enough to support
videoconferencing hardware and software the videoconferencing terminal will
provide poor performance. Once you have selected a particular videoconferencing
product, be sure to review the vendor's specifications.
Remember that the vendor will specify the MINIMUM requirements (usually operating
processor speed, amount of random access memory, video display board, and
video memory). In short: Overbuild
Can't I just get by with the minimum system configuration?
MINIMUM requirements should be interpreted to mean that there will be no
other programs active on the PC while the videoconferencing software is running.
If you anticipate that the videoconferencing PC will have an e-mail program
running, a web browser open, and be playing music from the CD player while
you are videoconferencing, you should select a PC that exceeds the minimum
requirements. Random access memory and choice of video board/video memory
have the greatest impact on videoconferencing performance. The video board
is important because the videoconferencing hardware displays the camera image
on the computer screen by using the computer's video board. If the codec
is very fast but the computer video board is slow it will degrade overall
A bunch of folks at my organization frequently need to be in the same
videoconference at the same time. I suggested we all "squeeze in" around
my desktop but everyone else just groaned. Don't you think that would work?
Who's right -- them or me?
Well, it's certainly possible to squeeze together in front of the desktop
so it's hard to say who's right. I guess it depends on your definition of "would
work"! Unless your desktop camera has a wide-angle lens, you won't be able
to fit everyone in front of it and the remote site will not be able to see
all of you. Also, depending on the size of your monitor, the people at your
end are likely to have to strain to share the view or remote participants.
Sound might work out O. K. for a small group. Microphones and speakers often "stretch" better
than the video peripherals do. Still, it's probably better to admit defeat
this one. Once you have more than a couple of people who want to conference
together, you either need to 1) bring everyone into a multipoint conference
from their own desktops via use of an MCU or 2) set up a group conferencing
everyone can meet around a group sized system. Remember, makin' do isn't
I heard that I could spend just a little more money on the audio/video
components for my PC and turn it into a group conferencing system. If that's
true, why do group conferencing systems cost so much more?
Imagine you have a VW beetle but you'd like it to carry several passengers
and their week's worth of camping gear and drive over rough terrain, like
a Ford Explorer. You have a chance of making it work if you a) understand
the design limitations of the Beetle, b) understand the design goals of the
van, c) have at least some money and time to spend, and d) are handy with
tools and improvisation. Same idea. If you can build it yourself, you might
be able to save some money. However, if you're not the type to re-engineer
something and then support what you have re-engineered, buy a group system "out
of the box"!
Sometimes my PC seems so sluggish when I'm doing anything else during
a videoconference. Where is processing typically done on a VC system?
Where your video processing occurs depends on the client you are using.
Some clients come with a special add-on board that will offload some or all
of the video work. Some clients, generally the cheaper ones, will rely on
your main processor to handle the video. Therefore slower PCs may see worse
performance while other applications (i.e. spreadsheets, word processors,
graphic editors, etc.) are running. The morale here is, if you want a cheaper
videoconferencing client, install it
What if I don't use a PC?
You are certainly in a "no-Win" situation! There is a notable gap in the
H.323 market in terms of both UNIX and Macintosh video terminals. This is
due to the large, general consumer market for Windows systems. But
the OpenH323 project has built tools for Linux and Wave3
Software has built SIP clients for both Apple and PC products. Multicast
tools are available for Unix.
I have a really nice, fast PC. It has two processors in it as well. Why
can't I use this system with a board assisted videoconferencing client?
Videoconferencing assist boards must go into certain PCI slots. It appears
that vendors have programmed their software to address a particular range
of IRQ numbers. The second processor typically fits into a slot higher up
and therefore throws off the IRQ numbers for the videoconferencing board.
Should you install the videoconferencing assist board in a dual processor
PC, mayhem ranging from refusal to operate to constant, regular video freezes
Just when I thought I was handling the Information Age pretty well,
the other day I got all flustered. It all started when my videoconferencing
client "rang" at the same time that my email beeped, my telephone rang, and
someone stopped outside my office door. Each interface seemed to demand that
it be "first". I let the phone go to voice mail, left the email for later,
took the video call but asked them to "hold" while I talked to the in-person
person. But this sudden crisis of communication left me very confused. For
the rest of the day, I kept trying to do strange things - Drag and drop a
phone number from the address book on my PC to my telephone. Eat a bagel
that was sitting on the conference table of a remote site I was videoconferencing
with. Pan my telephone handset around the room to "show" the caller my new
office arrangement. I even became convinced at one point (and quite frustrated
thereafter!) that I could cut and paste a good joke into a colleague's mind.
Am I going crazy?
You're not nuts, just harassed as well as maybe a little ahead of your time
(I mean, really, cutting and pasting into peoples' minds??!) Someday it will
all come together. For now, go outside for a nice quiet sit. Don't take the
cell phone, the pager, the PDA, the laptop, your pile of reading, your Dick
Tracy watch, or your Maxwell Smart shoephone. Just stop. Look. Listen. Learn
to be still.
I ordered one of the new USB videoconferencing clients. It
has some really nice features, but I'm having some trouble with the audio.
Do you have any advice for me?
A few quirks are noted from time to time. Some things to watch for include:
quality can suffer in a number of clients if the audio volume or
gain is too high or if 'Automatic Gain Control' is on and there is a background noise at the
same time. There are no audio problems at all if a headset is used.
- Strange behavior has been observed if 'Allow Adaptive Bandwidth Adjustment' is
on in a conference with some clients and in general on cable or DSL networks.
- In some cross-vendor connections, the video signal is reduced to QCIF
(as soon as the connection is established it can be switched back to CIF manually).
- In some cases if the mic is muted before a connection is established - the mute is cleared as
soon as a call is received. (this may cause a privacy problem which a user is not aware of).