if all of the tablets are on the same wifi network, you could use a serverless RTMFP group to join all of the students together with the teacher app on the LAN. you could then use group modes (like posting or directed routing) to send messages through the group between the students and the teacher.
the direct answer to your question, though, is that there isn't a "server" function in AIR. if you need a server, you'll need to use AMS/FMS or Cirrus.
if you aren't familiar with using groups, i encourage you to watch my presentation from MAX 2011:
Could you use the ServerSocket class?
ServerSocket is for TCP. you could use that instead of RTMFP.
RTMFP uses UDP. if you want to make an RTMFP server in AIR, you could use the DatagramSocket class, but you'd have to write your own implementation of RTMFP in ActionScript (see RFC 7016). note that at this time the RTMFP "Cryptography Profile" used by Flash and other Flash-specific data formats and semantics aren't publicly documented.
Thank you for the tip !
Excuse me, my answer is late, I was preparing a trip to Morocco when I received your message. I'm just resuming my work.
I have listened your presentation several times (I'm a French Canadian, just to be sure to understand well and because communication protocoles are totally new for me).
RTMFP is certainly the way to do what I want to do. I have a lot of things to learn and to try.
I want to thank you for the hint.
RTMFP works very fine for my project and better then I was expected.
Without your help, I think that I would never be able to do that. I used to teach science and chemistry in a high school for 33 years and I started to code only few years ago. But I continue to teach through my applications.
The only thing that didn’t work is the «NetGroup.Neighbor.Disconnect» that is not send from an iPad even if we close the application.
So if you can help me with that I will appreciate. If you can’t, it’s OK ! Nothing is perfect. It’s only an old reflex of teacher that wants to know if the students try to go on Facebook or …
Excuse my English, I'm a French Canadian but I have a friend that will help me to translate my app in English and I will let you when it will be available.
So thank a lot again and again,
NetGroup.Neighbor.Disconnect is sent by the local RTMFP group implementation to the application when it detects that a neighbor has disconnected.
depending on how the application is terminated, it's possible that RTMFP didn't have a chance to send the "abrupt close" message before the Flash runtime was terminated. in that case, the peer that's still running should detect that the peer that closed is no longer active after about a minute, and you should then see a NetGroup.Neighbor.Disconnect event.
note that you will only see a NetGroup.Neighbor.Disconnect for an actual neighbor -- that is, you must have gotten a NetGroup.Neighbor.Connect event for that peer first. peers can be members of a group but not direct neighbors, depending on how large the group is. if a group has more than about 20 members, it becomes very likely that any one peer won't be a direct neighbor of every other member of the group. in general, each member will have O(log N + K) direct neighbors (where N is the number of members of the group and K is a constant). specifically, it should be about 2 * log2(N) + 13 (that's where "about 20" above comes from).
I have 2 computers and 5 different tablets for testing (four iPads and a Samsung tablet). When I test the application with my 2 computers, I note that the disconnecting signal is sent instantaneously when I quit the simulator. With the tablet it could takes few second to one or two minutes. But, thank to Holly Schinsky, I read on Exit vs Suspend your iOS Application : Devgirl's Weblog how to resolve that. The signal is now sent instantaneously when I leave the application from an iPad.
For a group larger than 20 (my teacher app can manage group of 35 students), I don't foresee any problem, because the student app are posting their information so I believe that the teacher app would surely recognize each of them as member of the group (I hope so). I know different schools in my city that have «iPad classes» so I will surely try to test my app with one.