The isConnected method won’t help, it will return true even if the remote side has closed the socket. Try this: public class MyServer { public static final int PORT = 12345; public static void main(String[] args) throws IOException, InterruptedException { ServerSocket ss = ServerSocketFactory.getDefault().createServerSocket(PORT); Socket s = ss.accept(); Thread.sleep(5000); ss.close(); s.close(); } } public class … Read more
I achieved 1600k concurrent idle socket connections, and at the same time 57k req/s on a Linux desktop (16G RAM, I7 2600 CPU). It’s a single thread http server written in C with epoll. Source code is on github, a blog here. Edit: I did 600k concurrent HTTP connections (client & server) on both the … Read more
TCP / HTTP Listening On Ports: How Can Many Users Share the Same Port So, what happens when a server listen for incoming connections on a TCP port? For example, let’s say you have a web-server on port 80. Let’s assume that your computer has the public IP address of 24.14.181.229 and the person that … Read more
People say that the major thing TCP gives you is reliability. But that’s not really true. The most important thing TCP gives you is congestion control: you can run 100 TCP connections across a DSL link all going at max speed, and all 100 connections will be productive, because they all “sense” the available bandwidth. … Read more
I’ve written something similar to this in the past. From my research years ago showed that writing your own socket implementation was the best bet, using the asynchronous sockets. This meant that clients not really doing anything actually required relatively few resources. Anything that does occur is handled by the .NET thread pool. I wrote … Read more
netem leverages functionality already built into Linux and userspace utilities to simulate networks. This is actually what Mark’s answer refers to, by a different name. The examples on their homepage already show how you can achieve what you’ve asked for: Examples Emulating wide area network delays This is the simplest example, it just adds a … Read more
Here on Stackoverflow are several topics about P2P connections in browsers: Will HTML5 allow web apps to make peer-to-peer HTTP connections? What techniques are available to do P2P in the browser? Does HTML5 Support Peer-to-Peer (and not just WebSockets) Can HTML5 Websockets connect 2 clients (browsers) directly without using a server (P2P) Is it possible … Read more
Since you’re using a TcpClient, that means you’re checking open TCP ports. There are lots of good objects available in the System.Net.NetworkInformation namespace. Use the IPGlobalProperties object to get to an array of TcpConnectionInformation objects, which you can then interrogate about endpoint IP and port. int port = 456; //<— This is your value bool … Read more
Does a TCP socket connection have a “keep alive”? The short answer is yes there is a timeout enforced via TCP Keep-Alive, so no the socket won’t remain open forever but will probably time out after a few hours. If you would like to configure the Keep-Alive timeout on your machine, see the “Changing TCP … Read more
TCP communication is stream-based, which means it doesn’t handle any packets. Due to this, messages that you receive might be either partial or lumped together. You could for example send: Hello! How are you? But you might receive: Hello!How are you? or: Hello!How ar e you? (or something similar) To fix this you must apply … Read more