SharpUPnP is a simple library to help forward ports using UPnP
All of the methods in the SharpUPnP class are static so there is
no need to initialize a class instance.

Discover()
Before you do anything, you must run the Discover() method. This
tries to get the IP of your router, and then get the url of the
UPnP service to send requests to. If there is no UPnP device 
available, the Discover() method will return false.

FowardPort()
The ForwardPort method takes 3 arguments: an int port number, a 
ProtocolType protocol, and a string description. The port number
should be the port you are trying to forward. The protocol should
be either Tcp or Udp. These are the two protocols that the router
can forward to a device, and the one you choose should be the one
that your program is listening for. The descrption is just a short
string to describe what the port is being used for (generally the
program name).

DeleteForwardingRule()
The DeleteForwardingRule method takes two arguments: int port, and
ProtocolType protocol. This finds the forwarding rule with the 
corresponding port number and protocol, and erases it from the 
port mapping table.

GetExternalIP()
The GetExternalIP address does not need to be called for any of
the other functions. It is called inside other code, but it might
be of use to you for other purposes. This returns an IPAddress

SOAPRequest()
This method is if you want to make any other SOAP requests besides
the ones I have provided The SOAPRequest method takes 3 arguments: 
string url, string soap, string function. The url should be the url
of the UPnP service on your router. After calling the Discover method,
this will be stored in _serviceUrl, and you can just pass that. soap
should be the actual request xml that you are sending. function should
be a string containing the name of the UPnP function you are trying to
perform. This tells the router what the soap xml is for.