3.1.5.2 Error Handling

If a protocol message is received that includes an optional parameter that is not supported by an implementation, or a parameter that is not specified by this protocol, a requestor IP/STS MAY<50> ignore the parameter and process the message as though it were not present.

Protocol messages are processed by a requestor IP/STS or a relying party. If a message cannot be processed successfully, the protocol allows for a SOAP fault to be returned to the appropriate federation partner via a web browser requestor using an HTTP POST method.

However, this protocol does not require end-to-end error message propagation. A requestor IP/STS or a relying party MAY return an HTTP 500 error response to the web browser requestor, or they MAY redirect it to an error page.<51>

This protocol does not include provisions for automated retry or recovery processing if there is no response to a protocol request message. This protocol is designed to rely on the intervention of the user to notice when a web browser requestor operation has failed and to manually retry the operation that triggered the protocol.