XEP-0096: SI File Transfer

http://xmpp.org/extensions/xep-0096.html

"The traditional mechanism for transferring files in the Jabber community is the Out-of-Band Data [1] protocol. That protocol has several drawbacks:

It is not reliable.
It does not work when one of the parties is behind a firewall.
It provides limited metadata about files to be exchanged.

The current document defines a profile of Stream Initiation [2] that solves the problems with out-of-band data, thus providing a robust, reliable mechanism for file transfers over the Jabber network. Implementors are referred to XEP-0095 regarding the underlying concepts of stream initiation."

Depends on http://xmpp.org/extensions/xep-0095.html, http://issues.igniterealtime.org/browse/XIFF-90