Constantly reading/writing data over a TCP/IP Port. Which one?

Unfortunately I don't know much networks. I am writing a program that has two versions. A server version and a client version. Lets assume that the client versions are installed on, say 20 PC开发者_如何学Gos that are connected to the server over ethernet. The client versions needs to CONSTANTLY get some data from the server. The data is kind of serial. I wanted to know a way to broadcast the data that gets updated every second and make it available to all the other PCs in the network. Could I use the HTTP Port for this?, like writing the data to an HTML page or something? or Is there a better port or method for doing this?

Any ideas will be greatly appreciated.

This sounds like a pretty straightforward application of TCP sockets. The server would be set up to "listen" on a particular port (you pick the port number, say 12345), and each client would make a TCP connection to the server on that port.

Whenever the server has data to send, it would send it once to each connected client. This could mean that the server sends the data up to 20 times on different sockets, but that's fine. The client would read the data from its connected socket to the server.

There are other alternatives, such as UDP or even UDP multicast, but these usually end up being a lot more complicated because UDP doesn't guarantee that packets always arrive at the destination (and they may even be duplicated or out of order). TCP ensures that the data you send either arrives complete in the correct order, or doesn't arrive at all (in that case the connection would be dropped).

An example of this sort of multiple TCP connection is VNC:

VNC is widely used in educational contexts, for example to allow a distributed group of students simultaneously to view a computer screen being manipulated by an instructor, or to allow the instructor to take control of the students' computers to provide assistance.

There are many ways. you can choose any of them but i think, document below will help you a lot.

Multicast over TCP/IP HOWTO:

http://www.ibiblio.org/pub/Linux/docs/howto/other-formats/html_single/Multicast-HOWTO.html#sect-trans-prots