I need a good understanding of the inner workings of System.Web.Routing. Usually we define the RoutesTable. But how does it do the routing?

The reason I'm asking it is that I want to pass the routing to subapps. What I want to see working is a way of passing the current request to mvc apps that work in other AppDomains. Just to make it clear this is what I'm imagining I have a MVC APP that only has the barebone Global.asax and that loads in other app domains some dlls that are mvc apps.. and the comunication is done through a transparent proxy created through _appDomain.CreateInstanceAndUnwrap(...).

Hope this is clear enough.

Edit: from what I can tell the codebehind Default.aspx is invoked on the first page reguest and that starts the MvcHttpHandler that does all the voodoo of displaying the pages we are requesting. So it might just be a matter of passing the http context. If you have any ideas on matter please post your thoughts.