Tunnelling is a way to use the existing communication protocol(HTTP) and create a sub-protocol within it to perform some task.The sub-protocol created will contain all requisite information to an object and invoke methods on it and return responses to the client. Example : when you create an ftp using the existing http. How ? I will get back.............
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com