Send files over static IP from clients to server - c#

I'm a newb in this thing. I want to send files from a few client systems to a server over static IP. They're connected via a LAN. The files are created on a WPF app on clients and should be sent to the server which also has a WPF app.

The easiest protocols to you will be the ones you don't have to implement yourself. Can you use shared network drives, ftp or http? WCF would also be easy to implement, even if it's overkill.

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TCP Listener / Proxy in C#

I have several machines running an application that plays a video feed from a camera. Each machine is located behind a firewall on different LANs. I am trying to investigate an approach to be able to talk to these machines from an Azure web app and get access to the video they are streaming. I don't want to have to open ports on any LAN. My first attempt at this was to have a client running on each machine that contacts an intermediate Azure service via a TCP port, the port is kept open and the local machine sends data to the Azure service which basically downloads this data and then sends it on to any connected clients.
The problem I am having is the intermediate service essentially has to download each message and then retransmit it to any clients, I don't think this approach will scale as the intermediate server can become overrun very easily. Ideally all I would like the intermediate service to do is manage the connections between the local machines and the end client azure service so that they talk directly to one and other.
I guess this must be similar to what products like TeamViewer or LogMeIn do.
I'd appreciate any pointers or suggestions from others experience.

Windows Service communication, sockets, c#

i'm writing a server side application and a windows service which need to be installed on a remote host
the service returns CPU usage to the serverside application - this is NOT the problem
the serverside application deploys the service on the remote host. - also, not the problem
THE PROBLEM:
but how do i setup a socket connection between the two, when i dont want to hardcode the ip address? (for scalability) - do i need to use multicast or is there some devious way of doing this? is there another solution than using sockets? -
i'm new to writing Windows Services.
I need help figuring out how to communicate between the server and the service without hardcoding IP-addr.
thank you in advance.
MY SOLUTION:
I created a windows service, that reads a xml file with the IP and port of the Server application. so when i deploy my client application, i also create a xml file with the network information.
Regards Alex
A lot of communication platforms now use network discovery; there's an article on codeproject that goes into detail about using network discovery.
The problem was, I did not know what machine name the server was running on, in fact I wanted this to be flexible, and selectable by the user.
Seems relevant to http://www.codeproject.com/Articles/16113/Retreiving-a-list-of-network-computer-names-using
Have you thought of using WCF?
http://msdn.microsoft.com/en-us/library/ms731082.aspx
Regarding multicast, you can have a WCF server multicast announce it's availability on a network; see http://msdn.microsoft.com/en-us/library/dd456782.aspx
another solution could be to create the service as a console application with arguments (endpoint ip address) and then just deploy it with the arguments on the remote host

Best way to contact Desktop application remotely via Internet

I want to pass certain parameters to a desktop application remotely via the internet. I don't want my application to contact the server repeatedly, because many such applications can bring the server down easily. Is there a way to initiate the connection from the server? How can I identify the applications, as there will many of them running on many computers somewhere around the globe. I don't know where to start - I'm trying to do this in C# and ASP.NET/PHP on the server-side. Please give some advice.
Is there a way to initiate the connection from the server?
No. Not without having the client contact with the server first, informing it with the IP address, port to use etc... Which the server will need to keep for each client, hoping that they don't change (or get updated when they do change).
Long polling by the client is the right solution for what you are doing, even if you don't want to use it.
There are many different ways you could approach this, just thinking out of the box, both your app and the server could utilize a different mechanism for transferring the settings. I'm not recommending any of these methods, please don't shoot me down, they are all just ideas.
As an example, your server could connect out using FTP and output the updated settings to an FTP server on each PC. You could install something like Filezilla on each machine which runs your app. You'd obviously need to configure port forwarding on the router to allow the server FTP access.
You could use email. Setting up an email account where your server can login to send out the settings. Your app could possibly login to the same email account possibly even a single Gmail account to retrieve the settings.
Another idea would be to use a file sharing service like Dropbox, Google Drive or similar and where the settings could be shared. Obviously this would involve learning any API and I'm not sure if there are any restrictions on this approach.
The last idea and probably my preferred approach would be to host a web service and database on a remote server, both your server and the applications would connect to the same service to transfer the settings. This approach is obviously firewall/router friendly as all the clients connect out to the web service to collect the required data.
Hope this helps?

C# and ActiveSync communication / open and read files

I have a device connected to a host computer through cradle usb. Now, I'm just wondering if I could use C# sockets to communicate with the device (ie device sending data, host computer processing it then replying back to the device). How can I accomplish this? by that, what ip address etc etc.. do I have to change so that it would connect cause I have the sockets working on wireless. If not, then is there a way to connect to the device, open and read a file (a text document to be more specific) from the device to my host application.. any ideas?
Thanks! :)
Depending on your target device, when you connect via ActiveSync it likely makes a local RNDIS network connection between teh two devices. You can resolve "ppp_peer" as the partner's network name instead of trying to use a hard-coded IP address (IIRC the IP is different on XP than on Vista).
Be aware that it's not a full connection. TCP packets gets passed through, but things like ICMP do not.
Of course, this just gives you a socket connection, just like if you were to connect between two PCs. It's not going to allow you to do file system operations unless you have an app on the other side listening for commands. If you want that type of thing, Microsoft provides the Remote API (RAPI) interface (wrapped in managed code here)for a lot of basic commands, and it can be extended (with C) to do anything you'd like.

how can i send data over internet to any specific computer in subnet

I want to know how I can send or recieve data over internet to/from a computer in subnet
(this is specially in context to PPP users bcoz getting static IP is not so much in practice).
I actually want to create an application which can transfer file between 2 specific computer in WAN.
so what are things I need to know about to do the same..(ex. PRESENT IP or MAC ADDRESS etc..)
PROGRAMATICAL EXPLANATION ALTHOUGH PREFFERED,BUT IS NOT NECCESARY...
FTP?
There is a vast torrent of useful results in google, I seriously suggest to google before you ask here.
For instance, have a look at the top result: http://www.devarticles.com/c/a/C-Sharp/Network-Programming-in-C-sharp/
Apart from that, FTP, as suggested by Colin, may be what you're looking for. If you're new to using FTP in C# have a look at http://www.google.com/search?q=c%23+ftp
Put the information on a public IP server, so both computers keep polling if there is new data and send / download that data as needed. A single text file can hold necessary flags such as paths and other info you need.
server just need to be a web server, which means IIS or similar should be installed.
I'm thinking part of your question has to do with one of the computers not having a static IP address. If the two computers, A & B, don't know each others IP address, then an alternative is to use a server. Either A can store the information on the server to be picked up by B, or A can register his current IP address on the server for B to lookup and then connect to A, assuming firewalls don't interfere. Another scheme is that A and B can simultaneously connect to the server, and the server can relay data between the two.
Of course, all of this communication would be done using techniques such as those suggested by mafutrct and Colin.
This question sounds to me like the difficulties of NAT Traversal and trying to establish peer-to-peer connectivity over the Internet. I stumbled on this question researching the best way to set up Internet connectivity to a device that is sitting behind a firewall. I am assuming that the device behind the firewall has to initiate the connection, that a Internet server application (on a Public IP address) to at least manage the initiation of the connection is required, and the Internet server application may also have to act as a relay if the difficulties of NAT is not able to be traversed.
http://en.wikipedia.org/wiki/NAT_traversal
http://en.wikipedia.org/wiki/Peer-to-peer
A good example of this is LogMeIn. Where the application is installed on the computer that needs to be accessible over the Internet, that application communicates with the LogMeIn Internet servers, you can establish a connection to that computer either by initiating through the LogMeIn servers and connecting peer-to-peer over port 80/443 using NAT Traversal (this would be establishing a peer-to-peer connection) or by initiating through the LogMeIn server and the LogMeIn server acting as a relay if peer-to-peer is unable to be established.
Please note; you must have an application (something running) on both ends of the connection on the Internet, there is no other way. Just like FTP that was mentioned earlier (FTP Client, FTP Server)... but in this case it is peer-to-peer (basically you are writing your own Client and Server... or if you have to use a relay... Client--Relay--Server
http://en.wikipedia.org/wiki/LogMeIn
"The service connects the remote desktop and the local computer using SSL over TCP or UDP and utilizing NAT traversal techniques to achieve peer-to-peer connectivity when available."
The part I don't know is can the relay go in both directions; and I am figuring the device behind the firewall must have to constantly manage the open connection to the Internet Server that is the relay. Those are the questions I am wrestling with now.
Also, you may want to check out this post.
C# byte streams through TCP
From that time, till this date I have encounter so many problems with these four kinds of NAT that basically without an external server you cant do anything.
This is because, one computer can never find where the other one is located as suggested in the pic.
Here PC 'A' will never come to know about the port that corresponds to PC 'B' on R2B without an external server.Even more, if somehow u come to know about the ports you are still in a situation that the router wont allow you to access it if the request hasn't been made for your IP.

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