I have built a EMX demo board, and the layout is almost same as “FEZ Cobra” and the board has ethernet interface. In oder to explain my question, I have painted a picture.
There are 2 hauses, one is in New York and the other is in Washington. both have the internet Broadband Access.
If I am in Hause A and I have written a project about webserver for my EMX demo board, as in picture showed, user can use PC-a1,PC-a2 or PC-a3 in “Haus A” to open a webbrowser(for example firefox) and user can see the situation of GPIO in EMX board after typing a webadresse.
The users in haus B can also see the situation of GPIO in EMX board with PC-b1(b2, b3 or b4), if they open a webbrowser and type a webadresse.
I can image that I must use the TCP/IP knowledge, but I am very confused about it, how can build the access among the EMX demo board and the coputers in hause A(B).
Can anybody give me some tips, examples or documents?
What you have to do is “publish” the webserver from the internet; note this is NOT something to be considered lightly, it exposes your device to all kinds of nasty stuff you need to be aware of.
How I would approach this is to set up the router in each house to expose a TCP/IP port to the internet, and to “port forward” that port to the EMX device in the internal network. Then, when a browser comes along on that open port, the traffic gets forwarded to EMX and it’s as though the user is on the local network.
You really need to think about security, and you really need to think about DNS. If your ISPs in the two locations don’t give you static IP addresses, you may have to get the routers to register with a Dynamic DNS service so that you don’t have problems if the addresses on the routers change.
You really need to think about security. Can’t say that enough. If the system is read-only from remote locations, that improves the situation.
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