9. Architectural overview

An organizer, aggregator, “avatar” program (or controller) providing the user interface, having knowledge of attendee lists and groups, perhaps embed local business logic, and some useful level of functionality aggregating and displaying results from the FREEBUSY queries.

A CalDAV-compliant free/busy interface (CC-FBI) layer (or “proxy” which would field CalDAV free/busy queries from, and return results to, the organizer program. This interface would only have to support enough CalDAV to support free/busy queries.

A number of “connector” servers or services, at the edge of the network, to interface to systems which do not support CalDAV.