scope:

SIRI uses a consistent set of general communication protocols to exchange information between client and server. The same pattern of message exchange may be used to implement different specific functional interfaces as sets of concrete message content types. Two well-known specific patterns of client server interaction are used for data exchange in SIRI: Request/Response and Publish/Subscribe. Request/Response allows for the ad hoc exchange of data on demand from the client. Publish/Subscribe allows for the repeated asynchronous push of notifications and data to distribute events and Situations detected by a Real-time Service.