Questions about using Dimdim

My experience with Dimdim.

Dimdim is labeled conferencing software because it allows a number of people can interact in a conference or class room like settings from remote locations through a web browser. A conference is initiated by a presenter (or teacher) and is attended by attendees (or students).

I found that Dimdim had some great advantages and some disadvantages.

The advantages were:

• The server software is open source so there were not licensing or per seat fees .
• The server ran on Linux or windows so we were not tied to any particular operating system platform;
• The open source server version had a limited number of two way video conferencing and voice over IP capability.
• Dimdim does allow for public chat or private chat between conference participants and/or presenters. This can be handy for use with an audio handicapped.
• Most importantly, you do not have to load any exotic software on your box if you are a class or conference attendee. A browser and adobe flash player is all you need and most people have that anyway. If you are going to be a presenter you do need a freely available plug in that you can get from the Dimdim sight.

We have not tested the latest release of Dimdim (version 4) but it supposedly addresses some of the short comings we found in version 3. Version 4 allows:

• Recording and play back of meetings and classes.

That upgrade being noted I still consider the following as disadvantages:

• The level of control that a presenter exercised over the attendees is not adjustable. The presenter can let an attendee in the conference or throw them out of the conference but do little else. The presenter can also let the attendees have mic access or deny mic access. However, attendees can deface presentations or cause chat group disruptions. It would be nice if the presenter or teaches had greater granular control.
• The access security to a conference is a bit weak.
• The server security is weak.
• The time limit on conference prohibits leaving a conference open indefinitely. This limits the use of Dimdim for situation like emergency response centers where one conference or chat session might need to be open for days.

Some other interesting features are:

• You can sign up for a limited account for free. You do receive commercial advertising when using Dimdim if you choose to go that route.
• Currently (2008 08 17) you can purchase hosted accounts for up to 100 users for about $500.00 per year. You can brand these accounts also but I am not sure of that pricing.
• If you do not want to perform you own installation but you want a server at your location you can buy the servers software with support but it is considerably more expensive.
• I installed version 3 on windows and linux and it was a bit challenging to get working on linux. Once we got it working it worked well.

From a technical stand point (this section is for the techies):

• Dimdim uses Lighthttps as a web server. If you plan on putting it on a box with another web server you will have a port conflict. I recommend intalling it on it’s own dedicated box. It is possible to adjust the ports but it is a pain and causes problems for the attendees.
• The major components are:

o Dimdim 3.5
o Java 1.6.0
o Lighttpd 1.4
o Openoffice 2.4

• Windows install is fairly strait forward and includes all the components in the binary.

• Linux install requires the addition of the following libraries.

o libcom_err.so.2 -> libcom_err.so.2.1
o libcrypto.so.6 -> libcrypto.so.0.9.8b
o libcrypto.so.4 -> libcrypto.so.0.9.7a
o libcap.so.1 -> libcap.so.1.10
o libc.so.6 -> libc-2.5.so
o libcidn.so.1 -> libcidn-2.5.so

• In addition the following Python libraries need to be added:

o Cherry Python
o .Flup (another python library)
o zdaemon

Dimdim also requires that attendees have access to the following ports:

• 80 tcp/udp WorldWideWeb HTTP and HyperText Transfer Protocal
• 1935 tcp/udp Micromedia flash communication
• 4000 tcp/udp Terabase (unofficial ICQ server)
• 8100 tcp/udp Xprint Server (print service cross language printing)
• 8088 tcp/udp Radan HTTP (use to supplement HTTP)
• 9090 tcp/udp WebSM (protocol web system management)

The server uses ports:

• 80 tcp/udp WorldWideWeb HTTP and HyperText Transfer Protocal
• 1935 tcp/udp Micromedia flash communication
• 8088 tcp/udp Radan HTTP (use to supplement HTTP)

Since it is browser based, attendees can user any os platform that has a standard browser. We tested MS Internet Exlorer and firefox. My understanding is that Safari and Opera work also. You can use firefox to start a conference but it is a bit tricky. I would recommend using Internet Explorer to start conferences.

In conclusion, Dimdim proved to be a powerful and useful piece of software that should be able to handle most conferencing and training needs at a reasonable price. For more information just “google dimdim”, You should get the home web site.

Denis Oxford
MicroAssist