When does a session expires in sugar soap API

When does a session expire after its created? I know for REST API its 1 hour. But its not specified anywhere about soap API. I tried creating a session and ran a query in while loop to check if it will throw any exception, but even after 2 hours it was running without any problem.
In this example they have assigend the timeout as 90000 milliseconds but I think that's the wait time for creating the session it self.
Please help.