2010/10/21 Daniel-Constantin Mierla miconda@gmail.com:
Back to first paragraph. Are XMPP, MSN, Skype doing processing to these documents, or are they just pure storage systems for them with a white/black list access policy? In other words, I can publish my vcard and then tell the server if X ask for it, don't send my email address, just my web site address?
In both XMPP and MSN the avatar and vcard are retrieved by a watcher from the server if the watched gives the watcher permissions, so the server *does* interpret the permissions rules in behalf of the user. How to achieve this logic in a non-centralized architecture? I cannot imagine it.
So, if we assume that the "server" must be active part on the subscription (it must interpret permissions and know about subscriptions) then, why to implement in other way (direct/end-to-end presence) presence status retrieval when the watched user is online? two mechanisms?