In this chapter, you learned about the different options for authenticating your Sametime users. You learned about how LDAP and federated repositories work, and how to configure those in Sametime. You learned about how SSO works, and the steps you need to take to configure your Sametime servers to use that option. You also learned how to install and configure SSL. In the next chapter, you will learn how to configure and implement the Sametime Business Cards feature.