NetworkComms.Net does not infer the receiving data type. As such when you expect to receive an object you need to tell NetworkComms.Net what type it is going to be. In the case of the simple examples this is always a string, i.e. you see something like this:
NetworkComms.AppendGlobalIncomingPacketHandler<string>("Message" ...
Here you are telling NetworkComms.Net that you will be receiving a type of <string>, and that string will be sent with a packet type of "Message". For more information on this syntax I recommend you read about Generics, http://www.dotnetperls.com/generic.
Regards,
Marc