WCF sessions or pass username/password per call?
authentication, session, wcf
Solution
As blowdart mentioned, WCF Sessions are not the same as ASP.NET Sessions. You can read up on them here: http://msdn.microsoft.com/en-us/library/ms733040.aspx. Before you roll your own security, you'll want to get familiar with what WCF gives you out-of-the-box: http://msdn.microsoft.com/en-us/library/ms734736.aspx. They may get you close to your goal without writing a lot of code. Specifically, check out How to: Create a Secure Session. With secure sessions, the Client and Server cache credentials so you don't have to fully authenticate with each request. By default, you'll lose a secure session if the web server recycles. If you want a secure session that lasts through a recycle, you'll want to look at How to: Create a Stateful Security Context Token for a Secure Session.
Problem
For an enterprise type WCF service, where potentially 10K's of thousands of clients will be authenticating and sending data to central servers, what is 'best' practice when it comes to sessions or authentication? - does WCF support a session, if yes, should I use it? or should I simply pass username/password on a per call basis?