Design principles for developing .NET based Windows applications which interact with WCF & Java web services which inturn communicate with Oracle DB

Could you all share your experience/suggest guidelines/common mistakes made/ in developing .NET based Windows applications which interact with WCF & Java web services which inturn communicate with Oracle DB.

What are key points to be remembered before developing .NET Windows clients to WCF & Java Services? Is there any design choice to conisder connecting medium like LAN or WAN or VPN networks? What are the areas in design to consider talking to Firewall based WCF services.

Thanks, pv

It depends on the security (authentication, privacy, etc.) requirements you have.

There are still some general guidelines you can apply, most of them are described in this security guide: http://wcfsecurityguide.codeplex.com/

A few thoughts based on your questions:

• concerning firewalls, HTTP based connections are better accepted by firewall than raw TCP connections,
• Windows authentication can be used to authenticate LAN or VPN, not so easy with WAN,
• confidentiality is better achieved through message security than transport security in a WAN context