To futher define the propogation, replication and chaching activity area , here is a summary of the problem intended to help fram a theoretical analysis of the protocol. Thanks for comments from Phill Hallam-Baker. The net Let us take the model of a network of internet hosts. Messages may be sent between any two nodes.
Some hosts are permanent, some temporary.
One can send an unsolicited message to a permanent host with the assuption that it will be there to receive it. Temporary hosts may be available only from time to time. Whilst they may store state information in the protocol for their own purposes over long time periods, it is unwise for another node to require anything of the persistence of that state information. Documents Documents are stored originally on permanent nodes. The document is identified by a URL which contains the name of the node.