In the 6.0 release, Site Recovery Manager interacts with both vCenter Server (as before) and Platform Services Controller (PSC).
The PSC contains a Lookup Service to locate other services, a Licensing Service to replace the VIM license manager, and Single Sign On (SSO) service for authentication and token acquisition.
The vCenter Server management node contains a new Tag Manager to create categories and tags for Storage DRS or SPBM, and a new Authz service to replace the VIM authorization manager.
When programs connect to the local or remote SRM server, they must obtain a SAML token from the SSO service on the local or remote PSC. (The older login functions implicitly obtain a SAML token.)