If it is installed on a different machine, or you changed the default port to something different than 8080, make the appropriate changes to the URL above.
Options for interacting with the DSS for initial testing :
one convenient program to use for testing and demo is the oXygen XML editor (http://www.oxygenxml.com).
You can also use the open-source MirthConnect software to test rules, as well as in a production environment, because it includes support for web services.
testing using Eclipse, and the OpenCDS built-in testing client has been presented in OpenCDS Office hours, which you can find here: OpenCDS Developer Office Hours
Note that a variety of base64 converters for creating/reading base64 payloads are available on the internet, e.g.: