Wwai
WWAI stands for World Wide Article Information. This is a generic peer to peer based object information sharing protocol. Unlike (for example) the Gnutella protocol, data is inherently ordered which means that it's possible to traverse the network in a deterministic way. Nodes on the WWAI network are referred to as information providers. The main application for WWAI is for performing lookups on EPC values.
When an information provider receives a query, it answers it if
- It is authorative for the range in which the data falls or,
- It has a cached answer from another node
If neither of the above are true, the information provider passes it on to a neighbour which is topologically closer to the required resource. If the information provider knows of no such neighbour then the search procedure terminates. The closeness of a neighbour is based on the prefix portion of the EPC.
The ordering relationship above is achieved by a notification procedure which all information providers follow when they come online. This consists of notifying a number of reachable neighbours (ideally six or more) about the EPC prefix for which they are responsible.
The protocol also allows for subscription, for the purpose of receiving real time notifications about objects and registration, for the purpose of delegating authority.