I have a customer who is developing functionality (class libraries) to provide customers with data from multiple internal applications/databases through DNN as the internet facing GUI.  Additionally, they want to use the libraries to service internal requests from custom apps and would like all of these libraries to exist in a single location behind a firewall, while the IIS server sits in the DMZ.  So, the custom modules for the external DNN environment would make simple requests to the libraries on the server behind the firewall, which is where the business logic and data access would exist.

My first inclination would be to setup a web server behind the firewall and expose the class libraries through web services.  However, I'm not sure if .Net Remoting or WCF are better, more efficient ways to go about this because of the weight of web services and the potential size of the data coming out of the libraries?  The customer's reasoning for adding the layer between DNN and the business logic & data access is both security and scalability.  Also, they are not specifically limited tied to a particular version of DNN or the .net framework.

I would greatly appreciate any suggestions, recommendations, pointers and/or references that would help in this design and implementation...

Thanks!

Thanks Michael, I agree completely about performance and their security concerns, but am stuck in a position where I am unable to convince them to change the requirement that the dnn business layer must communicate with an app server behind the firewall, which is where all internal db connections will be made.  The dnn db will actually be in the dmz (I believe) as well and will not have any knowledge of, or connections to, any of the internal databases. 

I know remoting and wcf provides better performance than web services, but does .net remoting and/or WCF provide a better security alternative, or are you saying that there are no alternatives that provide greater security than an encrypted config file?  My goal is simply to provide the best architecture based on the customer's requirements.

Thanks again for any suggestions!

Right...  so, do you have any recommendations on securing host access?  I found this post... but, am curious if anyone else has done anything differently to make the host account more secure than it is out of the box.  I guess I'm looking for something beyond standard account management practices...

Thanks!