This graphic illustrates perimeter authentication. Support for perimeter authentication requires the use of an Identity Assertion provider that is designed to support one or more token formats. Multiple and different Identity Assertion providers can be registered for use. The tokens are transmitted as part of any normal business request, using the mechanism provided by each of the various protocols supported by WebLogic Server. Once a request is received with WebLogic Server, the entity that handles the processing of the protocol message recognizes the existence of the token in the message. This information is used in a call to the WebLogic Security Framework that results in the appropriate Identity Assertion provider being called to handle the verification of the token. It is the responsibility of the Identity Assertion provider implementation to perform whatever actions are necessary to establish validity and trust in the token and to provide the identity of the user with a reasonable degree of assurance, without the need for the user to re-authenticate to the application.