video conferencing

Thu Jun 9 11:54:18 EDT 2005

Justin,

I have worked with VC systems at a few companies for a few years using "professional" equipment so I feel comfortable answering a few things for you.

There are a ton of solutions for Video Conferencing - however the quality and price are all over the place. Minimum bandwidth for an acceptable (non jerky) conference is 384K per connection (and obviously more is better).  Any less than that and the picture and sound freezes, stops and starts or is fuzzy and snowy or the size of a postage stamp. Some devices will connect at 128 and 256 but unless this is an emergency connection to the South Pole you will be unhappy with the results. The T1 should be a good medium as it is conditioned bandwidth and will provide a consistant quality (see end note).  The DSL however is a burst type medium and since you are going overseas you may experience quality issues (see below). Also, unless it is a simple person to person face to face connection there are several questions and points you might want to explore first:

1) Do you have dedicated rooms at each end? (Hardware setup, lighting, sound - mic's speakers, etc.) The color of the room light/dark affects the quality of the signal.

2) What is the maximum, minimum and likely number of participants you are looking to have at each end? (Single table or theater style for larger groups) The larger the group the more important it is to have a good Mic that can be passed from person to person. It is amazing how amplified paper shuffling and side conversations muddy up a signal. Also a simple folder of paper signs like MUTE ON, MUTE OFF, CALL ME, etc. work wonders when the connection is not quite right.

3) Will you ever have more than a point to point conference (3 way or more)? Then you will need to look at a bridging service.  The major carriers like MCI, AT&T, Sprint, etc. all offer something. Cost is based on the distance to the "legs" for each connection - overseas is more expensive than domestic.

4) Clothing and background have a direct effect on quality of the signal - wild patterns, busy wall paper and your systems strain to keep up with the shifting image.  Ever see a weather man with a plaid jacket get "eaten" by the weather map?

5) Weather can effect your connection.  The overseas link to you can go through several media - copper, fiber, microwave, satellite all of these have some latency that a regular voice conversation is less affected by. Your brain essentially filters out the dropouts and other signal irregularities as you speak and listen - but video amplifies these issues.  Just think about and "remote" news casts you have seen.  The ones over seas or to the space station all have that "not quite right" look and sound to them and these are from organizations with millions to spend to make this stuff work at its best. 

6) Set up two local connection points to test equipment and procedures before you try to go international.  Try it inside the building as well as across town - the time you spend getting things ironed out when you can walk over to the equipment will be well worth it when you try the far flung connections.

There are more subtle points but these are the biggies.  I have worked with Logitech camera on a PC over a Cable broadband connection to a Polycom VC system and had fair results. Obviously router configurations, open ports for Video signals etc all come into play, not to mention netmeeting style white boards or collaborative software for presentations.

Joe Lukasiewicz

Dave Andruczyk <djandruczyk at yahoo.com> wrote:

--- Justin Bennett wrote:

> This is not neccesarily a Linux question but a general technology 
> question, I'm looking for an IP video confrencing solution. We have a 
> site in Europe and one here that we would like to do some Video 
> Confrencing between. Just between two fixed locations, probably 
> confrence rooms.
> 
> I'm looking for an IP solution to use over our VPN. We have a full T1 
> (1.5MB) here, and about double that in the form of DSL in Europe.
> I'm hoping to keep the traffic around 512MB or less to not congest our 
> connection too much.
> 
> Any reccomendations?
> 
> Thanks
> Justin

gnomemeeting

Dave J. Andruczyk

__________________________________ 
Discover Yahoo! 
Get on-the-go sports scores, stock quotes, news and more. Check it out! 
http://discover.yahoo.com/mobile.html

---------------------------------
Yahoo! Mail
 Stay connected, organized, and protected. Take the tour
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.nflug.org/pipermail/nflug/attachments/20050609/57a4c080/attachment-0001.html