I'm currently looking at options to allow me to build a remote COM-port solution.
The idea is to be able to access from my remote PC, another PC that's directly connected to a device locally via its serial COM-port.
I know that the obivous answer is to use a VPN between the 2 Internet connected PCs.
However, I need this solution to be as seamless to the end-user as possible.
i.e. no installing and configuring VPN software, etc.
So I was thinking that WebRTC would be great because the end-user can simply use their web-browser and not have to install any additional software.
My question is, is it possible to stream the COM port data between the 2 PCs via WebRTC?
If so, can you please point me in the right direction as to how I can go about achieving this?
Sorry if this is a ridiculous question, I'm very new to WebRTC, just exploring my options.
Thanks.
That should work great!
Networking wise you get NAT Traversal. That means the two computers can be in completely different networks, and still communicate. You may have to run a TURN server if P2P isn't possible.
Data wise you can exchange anything you want via data channels. It is datagram based and you can send/receive binary data. You get a callback telling you how much has been delivered, that way you can detect backpressure.
Are you ok with installing software on the remote host? You can do something like Pion WebRTC's data-channels. This shows you can have a browser connect to a Go process via WebRTC. Then use tarm/serial on the remote host to interact with the device.
If you want a browser on both ends there is the Web Serial API I haven't used it myself though. That locks you into only doing Chromium which might be an issue.
Related
I've been asked to implement VPN capabilities in an existing software project on an embedded system, in order to make the device available via network to an external server while avoiding trouble with firewalls (no need for encryption, just to make it accessible).
Unfortunately, the embedded system is based on a Cortex-M4 MCU, therefore Linux, which would allow for VPN nearly out of the box, is not an option. All I've got is an RTOS and a working LwIP stack.
I've used VPNs in the past. However, my network knowledge is rather limited concerning implementing VPNs, so I'm rather stumped. As I think, I'd use the current LwIP instance for building up the tunnel connection, and the application would use a second instance for the actual network communication, while the network interface of the second instance is a virtual one (like a tap device on linux), encapsulating its low level data and tranceiving it via the tunnel connection of the first LwIP instance.
Maybe this way I'd be able to create a custom solution for the problem, but the solution should conform to any standards (as the server will be any kind of sophisticated system).
So I wonder if anyone has been confronted with a task like this, and would appreciate any hint what to do, at least a direction where to look at.
Thanks in advance!
I have been struggling to find a definitive way to be able to connect my two computers wirelessly without a router and without setting up an ad-hoc network. I really hoped it would be as simple as changing my network adapter settings to have static IPs, say 192.168.5.10 on the first machine and then 192.168.5.11 on the other machine. But unfortunately, I can't even see these IPs on the output of ipconfig (or ifconfig). I have been researching this for quite a bit and no success yet... Any guidance would be greatly appreciated!!
Check WiFi-direct - it's designed for your use case. However, currently it's only supported by mobile devices (Android or iOS).
On desktop, maybe you could install an app and make one machine itself behave as a router, and let the other one connect to it. But I guess this solution doesn't solve your problem since it's no better than ad hoc mode.
The last solution I would suggest is a little painful: record MAC addresses of both machines, and generate the MAC frame by yourself somehow. This requires interception into the WiFi driver.
I have a somewhat basic understanding of network programming (and networking concepts in general) from taking a networking course in university a few years ago.
I remember being able to create a simple chat application, where the chat server is used as a central directory aware of which clients are currently online, but once a client knows another client it wants to chat with, the actual messages between them don't need to go through the server. I remember we could only test this over a bunch of LAN machines.
This C# chat program also has several comments mentioning that the program does not work over the internet: http://www.geekpedia.com/tutorial239_Csharp-Chat-Part-1---Building-the-Chat-Client.html
My question is why do these applications not work over the internet when "commercial" chat applications can. Surely, there is some way to make my computer accessible to the outer network even if its IP address is not valid outside the network of the ISP.
I see no problem with the linked-to code. The server doesn't even bind to a local address, which means it will listen for connections on all ip-addresses on the computer. There is however a comment for in the server article where the user changed the TcpListener object creation to bind to a specific address, which means clients only can connect to that specific address.
In the original server design, with using TcpListenet with only a port number, there should be nothing preventing its use on an Internet connected computer, unless there is a firewall blocking access.
Were you aware of networkComms.net and in particular the short chat example demonstrating the functionality here (It's less than 15 lines of code)? This was written specifically for people writing server-client apps in c# and given most of the problems you might come across will already have been solved and it might save you some time. This library is completely plug & play and has no issues working over the internet (as long as you can setup the necessary port forwarding where necessary).
Generally if both of your targets are behind NAT (so no true external ip addresses) and you are unable to configure port forwarding you need to look at 'TCP / UDP hole punching', quite an advanced technique.
Is it possible to connect to a Air app running on another machine via socket(assuming we know ip) or some other mechanism(which doesnt use Cirrus/stratus)? If it is can someone please help me on how?
Let me rephrase question, I dont want to connect to a server over socket. I would like to know if it is possible to connect from one AIR app on machine A to connect to another AIR app on machine B via sockets without cirrus. I'm not asking for someone else to do my work, I couldnt find any documentation or possibility of the above thing. My conclusion now is that it is not possible, but I would just like it to be verified by other people(experts).
Absolutely, as3 supports sockets. http://www.ultrashock.com/forum/viewthread/81676/
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/Socket.html?filter_flash=cs5&filter_flashplayer=10.2&filter_air=2.6
There are two ways to do it. One AIR app can act as a server by creating a ServerSocket object while the other app connects to this with the Socket class. The other way is to use the DatagramSocket class.
In both cases, the trick is that because of network access translation, the IP address to use is not always easily discoverable unless at least one of the computers has a static IP. If both computers are on the same network subnet you can look up the IP address needed to reach one computer from the other manually. Otherwise, the IP one computer must use to reach the other won't be the same IP that the computer sees for itself. This matchmaking is the service that stratus/cirrus provides.
See http://www.brynosaurus.com/pub/net/p2pnat/ for a description of the problem.
I am building an app that sends information between two iPhones. The app is working great but the one problem I am having is that I have no way of telling whether bonjour is choosing wi-fi or bluetooth to make the connection. I would like to allow the user to be able to choose which they prefer. Also, is there way to programmatically tell is the device's bluetooth is on?
There is NO WAY TO TELL.
It's just one of those weird things.
And in fact there is no way to programmatically choose WiFi or Bluetooth. It's annoying but true.
Often, multidevice games will have a warning for users:
"Be sure to TURN OFF Bluetooth, to
ensure you are using your WiFi
connection."
That's the situation.
Bonjour is just a service discovery protocol - it doesn't care what kind of network you have. It will discover services across a mixture of networks (e.g. via bridges and routers), so it doesn't really make sense to try to map a service discovered via Bonjour to a single type of transport layer.