[This is preliminary documentation and subject to change.]
The Local Policy Module (LPM) is a GQOS component responsible for retrieving and returning policy information used within the Admission Control Service (ACS). A default Windows NT LPM provides an interface to policy information that is configured and stored in the Windows NT 5.0 Active Directory. LPM is a generic term used to denote the implementation of a "courier service" used to provide the ACS with a means of retrieving policy information from a given policy store. LPMs will generally be implemented as a DLL.
LPMs provided for an ACS server or service must have a corresponding component (a DLL) that resides on the client. LPMs are thus implemented on the end node and the ACS server; this is a necessary logical configuration, as end-node generated user information, carried by RSVP to the ACS (which then gets forwarded down to the LPM), must be provided in a format that the ACS's LPM is expecting and can process.
It is important to note the difference between IETF draft technologies and Microsoft's implementation of such technologies. Subnet Bandwidth Manager (SBM), for example, is a technology begotten from an IETF draft proposal for regulating access to 802 subnets (IETF draft-yavatkar-sbm-ethernet-03.txt). ACS is a Windows NT 5.0 service (and a GQOS component) that incorporates SBM technology within its fold to incorporate regulation of access to 802 subnets in accordance with policy control.
In the SBM IETF draft, the implementation and integration of policy regulation within the SBM technology is extensively discussed and outlined, but is necessarily unspecific; with ACS and the LPM(s) that couriers policy information from a centralized policy store (the Active Directory when using the GQOS PE component), the generalized IETF draft finds specific implementation within Windows NT 5.0.