Synchronization Process

Synchronization is performed by the Synchronization Agent running in a loop in a separate thread. The agent is not run if ISynchronizer interface is not implemented by server extension.

When the agent has to disconnect a user or gather information from a NAS, it finds a synchronization object (or simply "object") associated with the NAS IP address. For that purpose ClearBox Server calls ISynchronizer::GetSynchronizerInfo to get ProgID and authorization info for the synchronization object. If this method says that no ProgID is configured for the NAS specified, no synchronization object is created.

NOTE. When used with RADIUS protocol, synchronization is made only with NASes specified by NAS-Address attribute in RADIUS packets (both authentication and accounting), not by IP address of the packet sender.

If there is valid ProgID, ClearBox Server creates the synchronization object and, if successful, calls IPersistPropertyBag::Load on the created object to make the object load its properties. It happens if this interface is implemented and object makes use of this mechanism (see Common programming considerations article). Next, ClearBox Server calls INASManagement::Init on the created object, passing authorization info. After this point object is considered to be run successfully.

When IRADIUSAccounting::ProcessAccounting or ITACACSAccounting::ProcessAccounting indicate that a user should be disconnected (setting status parameter to A_DISCONNECT), server calls INASManagement::DisconnectUser on the synchronization object.

When ClearBox Server has to gather list of users connected to the NAS (some time passes after previous synchronization operation), server calls INASManagement::EnumUsers on the synchronization object associated with the NAS. If this call was successful, server passes usersInfo array to the ISynchronizer::Synchronize method of server extension as usersList parameter. If this methods sets continueMonitoring to VARIANT_FALSE, no further synchronization is performed with this NAS.

See Also

Synchronization concepts