Rentnet is a distributed system that estate agents have decided to set up to manage rentals. They have decided not to use a centralized system, but to keep rental data themselves. Each agent also wants to use their existing systems which differ in operating systems (Linux, MacOS, Windows) and versions. There is a single advertising website that will gather data from the agents on an hourly basis. This will check for new properties, removed properties, and rented properties. Once connected to an initial system, a user will search property in a location. Consider how to arrange systems as an overlay, is this structured or unstructured?

Systems can also come and go. What happens to the overlay when this happens?

Required:

Design application protocols to disseminate system availability information. Also design protocols to enable the user to search and reserve rentals.

From the characterization of protocols in the lecture on IPC decide which combination of attributes you need, that is text- or binary-based, etc.

You need to consider Salzer and Reed’s End-to-End argument – how much of the reliability factor can you leave to transport protocols and how much must be handled at the application layer.

Your protocol must be designed to be future-proofed so that new services can be added and existing message formats can be changed.