Reputation: 309
I am trying to write an application which will run in many machines, and these machines will communicate with each other through sending a stream of UDP packets. Usually one machine will be sending many packets to another machine, until they switch and another one will do the same to another machine and so forth. Choosing UDP is due to the nature of the application (real-time/speed more important than reliability). I also understand that UDP is a connectionless protocol.
By doing a quick prototype, I managed to create a NIO Datagram Server (bind), and a NIO Datagram Client (connect). However, I realized that I can only send one way only from the client to the server (or maybe I am missing something?). I couldn't send in the opposite direction.
Also, since UDP is a connectionless protocol, I thought that it was supposed to accept many clients sending packets to it (n-client to one server), and the other way around (server sending to clients one-by-one or multi/broad-cast).
Should I create a server in the client listening to a different port to acheive two-way? Can n-client send packets to one server at the same time? I just want someone to clear this thing to me. No need for sample code (although it will be greatly appreciated), you can give me some pointers.
Thank you.
Upvotes: 1
Views: 1582
Reputation: 12538
For what you are describing, you need one server thread and one more client thread in EACH and EVERY instance of your program running on different machines.
Create a multi threaded program, with a serving thread, and a client thread - the client thread needs to know about all servers - IP and Port. The server simply listens on a port on the current machine.
If you run this same program on multiple machines, You will get a p2p group.
You can also set up a tracker on a free server in the internet. A tracker program will rest in a well known URL, and will maintain a list of participating machines. Each instance of your program when started on a machine will update the tracker of details necessary to connect to it, and the tracker can maintain a list of this data and share it all with any new instance coming up later.
Upvotes: 1