School with about 100 teachers and 700+ students, all with their own computer. Fairly new projectors in all classrooms, mostly NEC M322W, but also a few Epson and Smartboard (UFxx) projectors. Projectors have a network port, and at least the NEC ones will accept graphics (when sent from the "NEC Image Express utility"). The utility sees the projector as a device on the network, and does not require a dedicated/direct connection from computer to projector like some "wireless projectors" I have seen. Client computers connected to the network by WiFi can show a presentation/video on a projector connected to the same network by cable.
Primarily, we want to enable our teachers to connect wirelessly to classroom projectors. We can do that now, using the ImageExpress utility, as long as we limit connections to using a single IP subnet. We need a solution which does not impose that limitation.
It would also be a nice thing if we could allow students into this solution, but that would require a different level of management.
- Image Express utility requires that submitting computer and receiving projector be on the same subnet. This is probably to enable the utility to discover the projector. We have several IP subnets on the same physical segment, with routing in place, but the utility does not accept routed connections (i.e. between different subnets).
- We would like to enable our media server to push content directly to projectors, without the need to pass through a client computer. The media server runs on FreeBSD (currently as a FreeNAS plugin).
- For student access we would need some kind of authentication. I envision using either LDAP (personal login) or a randomly generated code to enter from display (so you need to physically be in the room to see what code you need). Authentication on projectors is single password handled locally on projector. I need multiple codes handled on a centralized server.
What did I do:
- Tested with the Image Express utility from Windows and Mac clients. The utility does not seem to put an excessive load on neither computer nor network. Our network should be able to handle 30+ simultaneous connections without congestion.
- Searched the web. Found one streaming solution that might be used to "bridge the gap": The MonaServer. However, I don't know what protocols to use.
- Looked at various client streaming software (including VLC player and XBMC) and media servers (did some tests using Serviio and Emby). As far as I can tell, none of those solutions have settings allowing them to communicate with the projectors. Some kind of "NEC-transcoding" seems to be required.
- Contacted NEC and sketched the situation as above, and asked whether they had server solutions, software or other tools I could use, or if they could disclose protocols that would work if I were to use MonaServer. Their response was a bit aside: they have another device coming to the market this autumn, essentially the same network device built into their projectors but with a HDMI output instead of the projector. (This is useful for my non-NEC projectors, provided I get a solution to the issues I presented above.)
Some system settings are governed by higher bodies, and cannot be customized. Altering network structure (e.g. to create one large IP subnet) is not an option. Setting static IP to teacher PCs is not an option.
A bit frustrating: We have projectors which will receive image data over the network. We have computers with software which can submit image data. Currently we still need to use VGA/HDMI/Displayport/Whatnot cables, with adapters to address different computers' port configurations, and somehow handle the wear and tear on both computers and cables (constant plugging and unplugging).
I could try to dump the network traffic with Wireshark or something, and see if I could decipher that to find some useful port/protocol settings. However, I guess that would take most of the time I have until retirement. I am not familiar with the intricacies of streaming protocols, and we need a solution in our lifetime...
Is there anyone who have pointers, in the form of protocols, software (client, bridging server, media/streaming server) or other ideas to solve this?
I may be banging my head against the wrong wall. If you have an obvious solution which I have not mentioned above, please tell me about it. I may be embarrassed, but I'll live ...
Edited by keme, 05 August 2016 - 01:59 AM.