I wrote messenger in c# with sockets, but i have little problem with ports. To clear comunication I have to open port on router which i use in my messenger. How to resolve this problem? Is method to automatic open default closed ports?
Thanks.
Asked
Active
Viewed 59 times
1 Answers
1
There are a couple things you can do.
The first is to change the programming of your application so that it uses the regular http port (80) for communication. This would allow your app to make outbound calls pretty much anywhere.
Alternatively you could use a high port number from 49152 through 65535. ( See Assigning TCP/IP Ports for In-House Application Use ).
However, depending on where you are deploying your application it is highly likely that all of those ports are blocked via firewalls; and neither will solve your problem
Most messenger type applications can't go direct due to firewall issues. For example, even if you use port 80, its likely the client machines have that port blocked for incoming TCP requests.
Instead they typically connect to a known public server. When one client wishes to connect to a different one, the server will route the message between the two clients. A very simplified look at this is: Client A sends a communication request to the server for Client B. Client B polls the server for messages, sees one and shows it on the desktop.
There are ways to keep the TCP connection alive between the clients and server in order to speed up communications; but that's the basics.
There are even ways for clients to directly talk to each other, when they determine that certain ports are open for communication or that proxy servers aren't going to interfere with the traffic. However, that's a little more advanced than a simple "answer" here can provide.
