Is it possible to make bittorrent client within silverlight, which will run in browser?
this would be unusual bittorrent client, he will download data from the server and will seed it. is it possible to do?
Is it possible to do within different, web tech, such as e.g. JavaFX?
Yes, completely possible. You can't receiving incoming connections, but that's no requirement for Bittorrent. The only thing that makes it difficult is that the peers you are connecting to need to serve a socketpolicy file on port 80 or 943, and almost none of them do. Without this policy, the Siverlight BT client will only work in the trusted 'Out of browser'-mode, which make it less usefull.
It's like a chicken-egg problem: as long as their is no large userbase for a Silverlight BT client, 'normal' nodes will not open port 943, and without that port, there never will be a large userbase for such an client.
Adobe solved this smartly by introducing Cirrus, their hosted rendezvous routing service which makes P2P possible from Flash without torrents.
No. You don't have access to the client's file system outside sandbox access.
http://betaforums.silverlight.net/forums/p/9351/29437.aspx
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I'm facing a problem that gives me a quite hard time ...
People having trouble to execute a program that needs specific ports to be open, sadly they don't know if its a clientside problem caused by blocked ports, of it its simply a software problem.
So I thought about making a program that checks if the user can access the provided ports, after I made the WPF application, I was thinking about having an easier access to such functionality and tried to produce a Silverlight Version.
Questions:
a.) Is there even a way to check if the user can connect to specific ports that aren't in the range of 4502 - 4534 within a silverlight application that runs as plugin in the web browser ?
b.) Is there a way to do this, even without having access to the specific server to provide a policy file?
If you trying to do it from the in-browser application that its a no. Trusted silverlight application should be able to connect to any port without restrictions.
We currently have a silverlight application (kind of a game) and we need to add more functionality which requires more interaction with the server.
We currently do all interaction by HTTP requesting data from the server and then processing on the client - works well, until we have a lot of requests or larger data amounts being returned.
Sockets in Silverlight only work on port numbers between 4502 and 4534, is there a way of making this work on the internet? A way of allowing the user to simply accept and open up a port?
What is actually blocking the port range?
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Just to add, is this somthing that is possible in Java (http://homepages.uel.ac.uk/2795l/pages/socketap.htm)
The only way to achieve this is via a proxy on the server or some sort of port forwarding taking place on the server.
This can not take place on the client side by itself.
What is actually blocking the port range is the SL runtime. It does this for security reasons.
In reality making use of sockets in an Internet based application would provide some hurdles most notably the need for the firewall to allow ports 4502-4534 to be open for Silverlight communication. This is one reason that the use of sockets is used more within an Intranet application where the need to open ports is non-existent (for the most part). Since Silverlight has defined these ports as the means of communication for their runtime it at least gives the admins some control over that range; versus allowing the runtime to operate on any given number of ports.
No direct way around it ( http://blogs.msdn.com/b/ncl/archive/2009/06/23/why-does-silverlight-have-a-restricted-port-range-for-sockets.aspx ).
I am using Rabbit single board computer. I would like to save the data I/O which is connected to another Rabbit single board computer through a wireless connection. Is it able to save the data inside the PC in a .txt file for example?
If you can establish a connection to a PC, and the PC is running some server to log data, yes, you could save to a PC. For example, the PC could run a TFTP server or FTP server on the same wireless network, and you could connect to it from the rabbit SBC and save whatever data you need to.
Yes, this is possible.
There are two parts to this scenario. Your embedded app needs to know how to connect to a server application running on the PC or network, and you must, of course, have said server application running on the target machine.
If you're sending entire files, FTP, as bdonlan suggested, is a good way to go. The protocol is well-understood and you can probably find a library to wrap it for you.
If you need to log data real-time, you'll need to have some sort of application which can receive messages or accept a socket connection, and a protocol to get the text across the wire(less). A web server may be a good way to do this, because you can POST chunks of data to the server with a simple HTTP request, and the server app can decide how to organize and store the information. Once you have a web server running, you may find it beneficial to build some pages that provide basic reporting functionality, so you can see the logged data from any web browser.
This could be less restrictive than FTP, but will require some web development expertise on your part.
Any reasonable solution is going to require that you already have a connection to the wireless network with a correctly-configured and functioning IP stack. Without that, you're probably out of luck connecting to any networked resources.
I currently need to make the silverlight 4 in-browser app that can receive push messages from the server. I presume using sockets is the best way, and will also allow a connection between server and client to transfer data and update the page.
But I am worried about firewalls and/or proxy servers.
Is it possible to have push technology, or even sockets at all, whilst behind a proxy that may block everything that isnt on port 80?
Or is it possible to have socket connections on port 80 which would be perfect because it would bypass both proxy and firewall. I am aware that there is a set range of ports available for silverlight, so im meaning a work around.
While on the subject...Would sending a mass block of data from silverlight be faster through sockets, ASP.NET AJAX, or connection to an ASMX web service?
Thanks a ton!
Here's a great article on WCF Polling Duplex (HTTP Long polling or COMET Style) hopes this helps. It's a bit out dated by the content will get you started.
http://tomasz.janczuk.org/2009/08/performance-of-http-polling-duplex.html
You can't connect to TCP socket with port 80 in Silverlight. As you've state there is a limited range of ports (4502-4534) you can connect to and thats it.
Yes firewall will be a concern, just as with other applications such as RDP remote access the firewalls involved between the client and server need to allow connection through one of the allowed port numbers.
Speed of data transfer is largely a function of its encoding. (I don't think AJAX is in the picture here). Ultimately sockets with binary encoding tend to be a bit quicker especially for frequent small transmissions. Whereas HTTP suffers with a bit more overhead however you are much less likely to have a problem with a firewall.
Unless you have a really, really good reason to use sockets use a HTTP based protocol instead. If you abstract out this part of your app reasonably well you could always swap it later.
Have you considered using a WCF PollingDuplex Channel? This allows you to create the "push" from server mechanism whilst sticking with HTTP. In addition much of the plumbing is done for you.
I am designing an application that requires me to access devices connected to the machine. We will have control of the machine, meaning control of the software and OS installed.
I know in the past one might suggest active-x controls, I was wondering is there a better solution? I have looked into Silverlight as an alternative, but not found much information supporting that design approach
Well, in theory, there's tcp support in Silverlight and so you could use that to talk to a local piece of software. In reality, tcp won't connect to the local machine unless you're in debug mode. So, that's a problem.
What people have been doing is creating a local WCF service and communicating with that. If you take this approach, don't forget to host up a cross-domain file as well.
I'd just add that if you can control what's on the client machine, WPF may be a much more straightforward answer :)
If you are speaking of the client's machine, Silverlight will not be of much help since it is sandboxed. In fact browsers and plugins are so locked down, that I think you should change your approach (maybe deploy your own client app, instead of using a browser/web app?)