Hi everyone Following the discussion in Oxford, here is a more concrete proposal for hierarchical error codes. Some observations / statements: * An NSA can choose to present a single error code or a hiarchy of errors. * A requester might get an error code related to an unknown NSA. This is okay. How to handle this is undefined, and is - like most error handly - subject to policy. * We need a timeout error code for to indicate a timeout error. * We probably need a "downstream error" to indicate that the NSA is functioning correctly, but that an unrecoverable error happened downstream. It is also possible for an NSA to report a "regular" error code along with an error tree, in the case that an error happened both downstream and at the NSA itself. Message Structure: <ServiceExceptionType> <errorId> <text> <variables> <DownstreamExceptionListType> <DownStreamError> <NSA> <ServiceExceptionType> </DownStreamError> </DownstreamExceptionListType> </ServiceExceptionType> Comments? Best regards, Henrik Henrik Thostrup Jensen <htj at nordu.net> Software Developer, NORDUnet