gistfile1.js

var net = require('net');

net.createServer(function(socket) {
	socket.setTimeout(10*1000, function() {
		console.log('timeout!!');
		socket.destroy();
	});

	setInterval(function() {
		if (socket.writable) {
			socket.write(Date.now()+'\n');
		}
	}, 1000);
}).listen(8888);

// and run: nc localhost 8888