The following diagram shows how Silk Meter licensing and metering are used in an application.
A client accesses the Web server and requests usage of a Silk Meter-controlled application or component.
The request is passed to the Usage Control Server,
which determines whether or not to grant access to the e-business application,
based on information contained in the policy.
Note: If there are multiple valid policies for the same product,
the first one in the list that satisfies the request is being used. The
following policies are ignored in this case. The order in which the policies
are validated is the same as you see in the list of policies on the Policy Administrator window.
The Usage Control Server then authorizes the application to grant access to the requested application or component via the Web server. If the Usage Control Server denies access to the application or component, the Web server may display an error message.
Metering data is collected and stored. These statistics are accessible from the Policy Administrator window.
Design considerations
Silk Meter is constructed for flexibility and extensibility:
Communication protocol: IIOP is used, guaranteeing interoperability with programs built using any CORBA-compliant object request broker. The protocol between Silk Meter clients and servers is fully documented.
Security module: The security module is isolated from the rest of the system, permitting substitution with encryption algorithms other than the default MD5.
Policy format: The policy format is extensible, and the management software is independent of policy content.
Interaction with other CORBA compliant systems: Silk Meter fully conforms to the OMG COS Licensing Specification, which defines the standard for object access control and usage metering, enabling interaction with other CORBA compliant systems.
