It’s not too long ago, that I was comparing videoconference carts to “integrated rooms.” Now it’s time to compare Skype to videoconference carts. There are many ways and reasons to use Skype in the classroom; there are also many ways and reasons to use some form of H323 videoconferencing in the classroom.
Danielle Letter, TWICE President Elect, invited me to present with her last week at a MACUL preconference workshop. We started making a wiki, and spent considerable time discussing pros and cons of various tools. Since then, I’ve been thinking more about Skype in the classroom and H323 in the classroom; and the pros and cons of each tool. (I’m using H323 to be very specific about the type of videoconferencing I’m referring to. H323 is the protocol used to communicate.)
|Picture||Skype||H323 Videoconference Cart|
|Viewing||Unless connected to a projector; difficult for the whole class to see||Monitor/projector usually designed for the whole class to see|
|Micro-phones||The computer mic is designed for one person at the computer; so audio can be seriously problematic. You might have trouble with the other site not able to hear you. You may also have echo cancellation problems – where the school at the other site hears themselves talking.
This may be able to be solved if you purchase an echo cancellation mic designed for a conference room table or similar situation.
Another limitation may be the length of the microphone cable.
|The microphones with cart videoconference systems are designed for whole group use. They are usually on a 30 foot cord, easy to move around the room. They have echo cancellation built in, so no echo problems.
These microphones also usually do well with adults speaking from anywhere in the room; and often the students. But if students are presenting, it works better to have them come up to the mic as shown above.
|Access right in your classroom all the time. Easy to just jump in and use it.||The cart may be in the library or down the hall. Have to schedule it and share among all the teachers in the school. In some districts, VC is mobile throughout the whole district; or only available at the high school.
Depending on cart design, it may be hard to move around the school.
|You can share your desktop with another site, but you cannot hook up other inputs such as the document camera.||Usually several inputs for DVD, document camera, computer, etc. Multiple types of visuals can be shared with the other site.|
| Sharing your computer
||Very easy to share your computer screen (PowerPoint, movies, etc.) with the other site.||If you’re using H.239 (People Plus Content; DuoVideo; etc.), there are several scenarios where you may not be able to share your computer with the other site.
If you’re using S-Video to connect the computer to the videoconference system, it should work great all the time.
|Camera||Usually with Skype you have a little web cam which cannot zoom or have presets.||The camera has great ability to pan, tilt, and zoom. You can set a preset on any spot in the room (at least 10 or more presets). You can set presets on additional inputs so you can easily switch between the document camera and students, for example.|
|Remote||Usually you can only control the videoconference from the teacher’s computer.||An infrared remote control allows controlling the videoconference from anywhere in the room.|
|There is a potential that you could overwhelm the school’s bandwidth if every teacher did a videoconference at the same time.||With a cart, there is a physical limitation to only do one videoconference at a time. Easier to control the bandwidth used.|
| Picture Quality
||The picture quality varies widely depending on the cameras used at both ends and the bandwidth of the two sites participating in the conference.||Cameras tend to be higher quality, even HD, and so the picture quality tends to be higher than with Skype. It still can vary based on the bandwidth of the sites involved in the conference.|
|Skype only connects point to point with video. Yes you can have 10 audio participants in a call; but not video.||With the use of a bridge/MCU, you can connect many sites together. Some essential applications include the ability to share the cost of amazing experiences from Global Nomads Group and COSI Columbus across several participating schools, as well as getting multiple perspectives from around the country/world at the same time. MysteryQuest and all its spinoffs are multipoint events; ASK programs work best sharing the cost of the author with 3 schools.
In addition, since I have a bridge, I can monitor even my schools’ point to point calls (by putting them up on the bridge and adding my site). This way I can provide support and encouragement to teachers as they participate. They aren’t “alone” with the technology. I also like to watch the VCs so that I can recommend the good ones to my schools.
None of this is possible with Skype.
||$100-200 depending on the quality of the web cam and microphone you invest in. Skype itself is free.||$2000-$9000 depending on the size of the monitor/projector, type of cart, and additional peripherals used.|
|Available Content||Many other classrooms to connect to; as well as authors. You can also arrange to connect with any guest speaker you can find. More resources here.
It is easier to connect to international sites with Skype as it’s more likely they can afford a webcam and Skype than the H323 videoconferencing software or equipment.
|In addition to other classrooms, authors, and guest speakers, there is a large community of zoos, museums, and other organizations who offer programs to schools. We call them content providers. Most of them cannot offer their content via Skype because they have so many awesome visuals to share with your students that they cannot connect to show via Skype.
It can be harder to connect to international sites as they may not have access.
What do you think?
To me, the content available via H323, and the quality of the conference are the two main reasons to keep using H323 carts; even though Skype is free and easy.
What do you think? Did I miss a comparison? What would you add? Please comment!
8/29/10 Update: Added a section about international connections to the available content.
I think that is a great side by side comparison. We’re often asked about Skype versus H323.
Great comparison! Would be interesting to also see Vidyo added in to the discussion. What about Dimdim as well?
When I free up a couple of extra laptops I was thinking of setting up a bridge between H.323 (probably Polycom PVX) and Skype connecting a/v outs to a/v ins to just see what might happen.
Thanks again for the great comparison.
Bob Dixon at OSU has been working on this idea of the H323/Skype bridge. You can read more about it here: https://wiki.internet2.edu/confluence/display/k20t/2009+Spring+MM+-+K20+Meeting
Also, Vidyo is definitely in the works….
I don’t plan to cover Dim Dim though because it is more of a webinar format tool, and because it doesn’t connect to H323.
Thanks for your comment.
Please compare specifically the differences in security. How can Skype be compromised vs. H.323 videoconference carts?
Steve – I’m not a network specialist, nor do I claim to be! I’m just an educator interested in using VC in the classroom.
That said, a bit of google searching can find you some information on security for both Skype and H323.
Here’s a couple I found:
Hope this helps. I encourage you to search Google and read further.
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