bbnet defines a set of baseline cryptogen contracts that provide all of the primitives for interacting with the data mesh. contracts don't have to be provided by the network. by convention, the null address 0x0 is used interally to mark names that resolve to out-of-band contracts. oob contracts have limited utility since there is no particular guarantee that another peer will understand the messages generated by your builtin contract. bbnet resolves this by friendly convention and it is expected that other cryptogen networks will eventually start using a modified baseline suited to their own needs.
bbnet is a small suite of protocols that work together. each layer is designed to be useful independent of the layers above. the scope of each component is intentionally narrow. gemini for browsing hypertext documents, then using gemini to build a gossip network (cryptogen), then using cryptogen to send signals to bootstrap activity on other protocols. bbnet is conceptually a toolkit for composing network applications from smol components. tracker comes from another direction, but its also meant to hook into the bbnet structure to connect graphical applications to the network.
bbnet operates only over local data, so as far as it is concerned there is no network. I/O is performed only in the form of reading and writing messages, which have an added size restriction and a specific schema.