JetspeedSecurityService Vs PortalAccessController

[Shan Gopalakrishnan <sg...@cisco.com>]

Hello All
 
I'm trying to understand the security model of Jetspeed as I have some
requirements to change some of the out of the box implementation.  If I
go through the
JavaDocs I see two interfaces which talks about the Access Control.
Below are the two
 
1) JetspeedSecurityService,  Implemented by JetspeedDBSecurityService
which is stated as 
 
"The Security Service manages Users, Groups Roles and Permissions in the
system. The Jetspeed Security Service extends the interface of the
Turbine Security Service, adding on the Jetspeed specific interface:
AccessControl for controlling access to portal resources (portlets,
panes). "
 
 
2) PortalAccessController , Implemented by RegistryAccessController
"The PortalAccessController interface defines a contract between the
portal and security provider required for authorization to portal-secure
areas. This interface enables an application to be independent of the
underlying authorization technology."

Can someone give me clear idea of  how these two are inter linked if it
is ? or why there is two ?

Thanks a lot in advance.

-Shan