Videoconferencing over the Internet
Table of Contents
|CU-SeeMe is not a videoconferencing system
like the commercial ones. It's not a package just a little software.
CU-SeeMe works over the Internet no matter what your access point is. It
means it works with T1-T4 lines, cable or xDSL, ISDN, LAN, and modems
(28.8Kbps or better recommended) no need to say, the faster your
connection, the better is the result. For information, a 14.4Kbps link
doesn't allow to hear much more than little clicks from time to time but
it still allows you to see the video part of the stream. At 28.8K or
less, you should consider 5fps is a good result but this gives enough
Some times after CU-SeeMe appeared, other incompatible systems appeared which were Cinecom and Freevue but they did not spread as much as CU-SeeMe or the upcoming (at that time) NetMeeting.
The "two faces" Logo is a trademark of Cornell University. It is an original design by Aaron Freimark.
The information has been removed since the list that was maintained at the Cornell University seems to be discontinued. (Thanks Doug)
Since the beginning of the year 1996, the main software and hardware suppliers have been involved in Internet videoconferencing. The first products that appeared were Intel Internet Video Phone, Microsoft Windows NetMeeting (formerly Microsoft NetMeeting) or VDONet VDOPhone to name just a few of them. (Note that most of the links may be broken by now since the products have either evolved or simply disappeared.)
Windows NetMeeting 3.01 should give better results than the oldest versions of this program but if you are experiencing unrecoverable problems or you prefer the previous user interface then you can follow this link for downloading NetMeeting 2.11 for Windows 95, 98 and NT 4.0. On the other hand, the development of the NetMeeting program as we know it today is now discontinued, an upcoming version of the product will be part of the Windows Messenger and the HailStorm project.
|389||[TCP] LDAP packets / Internet Locator Service|
|522||[TCP] ULS packets|
|636||[TCP] LDAP/SSL packets|
|1002||[TCP] LDAP packets / Internet Locator Service (Windows 2000+)|
|1503||[TCP] T.120 (Data Conferencing)|
|1720||[TCP] H.323 call setup|
|1731||[TCP] Audio call control|
|>1024 *||[TCP] Dynamic H.323 call control|
|>1024 *||[UDP] Dynamic H.323 streaming Real-Time Transfer Protocol|
As defined in H.323, audio and video streaming is performed via dynamic
ports above 1024.
Please download the NetMeeting V3.0 Resource Kit for more information.
The following Knowledge Base articles are available for specific installation and uninstallation instructions:
For information about firewalls and proxies configuration please take a look at the following sites:
Windows NetMeeting Resource Kit. Chapter 4: Firewall Configuration
How to Establish NetMeeting Connections Through a Firewall
Using H.323 ProShare Conferencing Products Across Firewalls
http://www.cisco.com search for Cisco Multimedia Conference Manager (MCM)
For information about setting up an ILS please take a look at:
(or search for the Q238994 article in MSDN or TechNet)
Once you have the videoconferencing software you may wonder how to contact other people and place a call. So keep reading I will talk about this now.
If you want to use your videoconferencing software with someone in your neighborhood without using the Internet and avoid the jam this is possible but requires some settings. If you want to know how to make such a connection please download my paper and follow my step-by-step instructions. Should you need more information or for any feedback please contact me. A little email telling me about your success thanks to my paper is very welcome too ;-)
Download my paper: Running a videoconference between two computers without Internet
One other drawback with videoconferencing over the Internet was the not-so-trivial way to reach the other end for a private conference. I mean for people with a dynamic IP address who are most of us who use an ISP to connect to the Internet. As opposed to the traditional phone, the number to call is not always the same and here lays the trouble.
One method was that both ends who wanted to make a private conference join a same common reflector. They had then to exchange their IP addresses there, disconnect from the reflector and one of them had to call the other with the IP (s)he was just given. Other ways to do that were to exchange IP addresses in e-mails or with PowWow.
Some time later, some companies (e.g. Four11 now part of Yahoo!) which were maintaining directories of people on the Net solved these hassles by adding a feature to their web sites. This feature as a sub-directory enabled anybody using one of the most known Internet video phone applications to contact another party currently connected just by clicking his/her name from the list. You just had to register with this free service and to forget the troubles !
The first Instant Messaging (IM) application that was released is
Mirabilis. ICQ like all the other IM applications (e.g. AOL Instant
Messenger, MSN Messenger...) et you know when your friends, relatives or
colleagues who use the same program are online. To make that possible
Mirabilis, for example, assigns you an unique number an Universal Internet
while the other systems use an identifier or your e-mail address.
If the person you want to call is online you simply have to right-click on his/her name in the list and click the name of the Internet video phone application that you want to use and wait for your correspondent to respond. If you have problems with this you may have to download my ICQ Fixer, the versions since 98 of ICQ have a bug that make NetMeeting calls impossible.
Most IM applications now support their own videoconferencing feature though they usually are not interoperable. I highly recommend the latest version of MSN Messenger which has integrated audio and webcam capabilities compatible with all Windows version. An alternate real-time videoconferencing feature is only available in Windows Messenger (Windows XP only) but this very version is not able to place NetMeeting calls anymore (though NetMeeting is still available in Windows XP, click here for more information.) With MSN Messenger you can see when your contacts are online and establish a video connection right away without launching any additional software. The quality was enhanced compared to NetMeeting. Another reason why I recommend MSN Messenger is because it fully supports UPnP-compatible firewalls and routers which makes the TCP/UDP ports configuration totally transparent to the user which is a great step forward.
Another interesting and promising set of videoconferencing and presentation tools from Microsoft is called ConferenceXP. It is open-source and provides many advanced features like multipoint videoconferencing, multicast support, interfacing with Windows Messenger, etc. Unfortunately this requires an Internet2 connection but it may work in some ways in a multicast-enabled LAN. See the Microsoft Research ConferenceXP project.
Microsoft solved the problem of finding people since the apparition of NetMeeting with its ILS (Internet Location Server, formerly ULS). The only thing you have to arrange before the call is the time at which you want to make the conference. Otherwise just look at the directory find the person you want to call, select it and click the Call button. That's it. This is really much more easy than the original CU-SeeMe way. Everything would have been perfect if these servers were not always overloaded and/or populated with mad people. Check the Windows NetMeeting Zone site for alternate ILS servers.
In mid-November of 1996, Microsoft announced a commercial version of its Internet Locator Server (ILS) (formerly User Location Server) which was part of the Microsoft Conference Server. The strength of ILS was supposed to be its ability to handle tens of thousands of users per server at least in the specifications, reality shown that it is a bit different! The ILS software is still available for download and in spite of the problems over the Internet (overload and message contents), an ILS is still useful for companies interested in the NetMeeting technology: they can setup their own ILS for their private use on an intranet or for private or public use on the Internet. They only have to download the ILS software (V2.0) from the Microsoft Windows NetMeeting site.
With Windows NetMeeting 3.x, Microsoft set up a new server called Microsoft Internet Directory. It was supposed to correct some of the problems (not only technical) encountered with ILS but it seems that the goal was not reached (because people found alternate ways to say what they wanted to say!) then you could only make searches and not display the whole directory. The obvious thing is that people are now mostly all turning to instant messaging like AOL Instant Messenger, ICQ and now MSN Messenger to call their friends and relatives and give up with directories. With the release of Windows NetMeeting 3 Service Pack 1, Microsoft shut down all its ILS servers (probably for the reasons exposed above) and recommends using Windows/MSN Messenger.
Another method that is usually used for personal Web or FTP servers and
that can be useful for placing videoconferencing calls too is the use of a
dynamic DNS. A dynamic DNS is especially interesting for people who have a
dynamic IP address (e.g. most people who connect to the Internet using a
dial-up connection and some ADSL or cable modem users.) Thanks to this
feature, you can reach someone or be reached with a fix DNS-like address, a
Fully Qualified Domain Name (e.g.: myhost.dhs.org) instead of a dynamic IP
If someone wants to call you with a videoconferencing program like NetMeeting or CU-SeeMe and your program is running and you updated your dynamic DNS using a client application (e.g. my DynSite program) then anyone can call you with your dynamic DNS instead of your IP address. Since your dynamic DNS will always be the same, and as long as your are online, anyone will be able to contact you, whatever your IP address is. They will never need to know it anymore to contact you.
You use the dynamic DNS just like you'd use an IP address e.g. in Windows NetMeeting 3.x, select Call/New Call and type the dynamic DNS of the person to call in the To field of the Place A Call dialog box.
At the beginning of desktop videoconferencing, the systems from different brands were not all able to communicate with each others. The same incompatibilities appeared with videoconferencing over the Internet this means that one had to use the same system (or software) at both ends to be sure to be able to collaborate. But since then more and more standards have been done and things are more and more smooth. Now almost all the videoconferencing systems are compatible with each other because they are based on the H.32x (and many other) standards. Here are a very few of them:
Here are some of the standards used in videoconferencing.
For more information please take a look at the DataBeam's primer pages on T.120 and H.323.
|T.120||real-time, multipoint data communication|
|T.126||still image exchange and annotation (shared whiteboard)|
|H.320||videoconferencing over ISDN|
|H.323||videoconferencing over LAN (and Internet)|
|H.324||videoconferencing over POTS (phone lines)|
Videoconferencing systems use the CIF format (and its muliples) as the format of reference for the size of the video. Here are some of the available formats:
Size (in pixel)
|sub-QCIF||128 * 96|
|QCIF||176 * 144|
|CIF||352 * 288|
|4CIF||702 * 576|
The Openh323 Project, open source H.323 stack and more open source stuff for Internet telephony.
Many web services now offer free or low rates phone calls over the Internet. You can call any phone numbers from your PC either using a conferencing application or an applet on a web page. Some of these services are listed below.
|4eCalls||FREE web based telephone calls to Ireland, UK, US and Canada. All free calls are limited to 6 minutes.|
|DialPad||Low international rates.|
|Go2Call||Low international rates.|
|HotTelephone||Call 30 destinations for free.|
|MediaRing||Low international rates.|
|MSN Messenger||Free phone calls within the U.S. Low international rates.|
|Net2Phone||Free phone calls within the U.S. Low international rates.|
|PhoneFree||Low international rates.|
|WowRing||FREE phone calls to and within the U.S.A., Canada, France, Germany, Hong Kong, and the U.K. from anywhere in the world.|
For more free PC-to-PC and PC-to-Phone services, see Free World Dialup