once you setup everybody else for windows authentication, you are almost done.

change the authentication in the sdata web.config file its probably set to standard slx still

sdata it selfe already is set to use windows authentication.

I've written some external webservice that is firering some sdata calls. this webservice is called out of the slx client.

so your solution is not working for me because I still need some the parameters "username" and "password" of any kind of user that is calling the "SDataService" Property.

The other way would be to call the webservice with username and password within the url of my webservice. But this would be much more unsecure as the current solution.