If you're developing this on a remote machine, your network setup needs to allow you to connect to that machine on the port you have selected for your TCP server (10000 used as example in this article). You can test this by doing:
# telnet <remote_machine_host_or_ip> 10000
It's important to understand that while HTTP is a TCP-protocol, TCP/Sockets are not the same thing as HTTP. TCP is a low-level protocol for network communication, Sockets are a programmatical technique for developing TCP-capable programs, and HTTP is a higher-level protocol developed "on top of" TCP.
So, connecting to this simple TCP-server with your browser will not work as the browser will try to "talk" HTTP with it. This article only demonstrates the very basics about TCP/Sockets-programming. Which, for that matter, could be used as the base for a HTTP-server, but that is different story :-)