License: Public Domain

A simple UDP echo server which can be used for some NAT traversal routines (UDP
hole punching). There is although a simple demonstration client.

Building:
---------
Just enter make in the client or server directory.

Tested on Linux only.

Running:
--------
start echoserver [Port] or echoclient [IP] [Port] to start the server or the client.


Protocol:
---------
The client sends a UDP datagram consisting of 

condata $SomeKey

to the server.

The server replies each request with

condataReply $SomeKey $IPAddress $Port

The $IPAdress is in regular 4 Byte Notation: 1.2.3.4

The $SomeKey isn't a security feature but can be used to distinguish between 
different ports during a Hole Punching Procedure.

Example:
--------
Client to Server --> condata 0x12345678
Server to Client <-- condataReply 0x12345678 127.0.0.1 6843

Warranty & Security
-------------------
Plaintext UDP is not secure at all. There is no warranty for anything.