Editing Gnutella (section)

== Protocol features and extensions ==
Gnutella once operated on a purely [[query flooding]]-based protocol. The outdated Gnutella version 0.4 [[network protocol]] employs five different packet types, namely:<ref>Dye, Mark. McDonald, Rick. Rufi, Antoon W., 'Network Fundamentals', Cisco Networking Academy, Cisco Press, Ch 3. p. 91</ref>

* ping: discover hosts on network
* pong: reply to ping
* query: search for a file
* query hit: reply to query
* push: download request for firewalled servants

These packets facilitate searches.  File transfers are instead handled by [[HTTP]].<ref name="Dye, Mark p90">Dye, Mark. McDonald, Rick. Rufi, Antoon W., 'Network Fundamentals', Cisco Networking Academy, Cisco Press, Ch 3. p90</ref>

The development of the Gnutella protocol is currently led by the Gnutella Developers Forum (The GDF). Many protocol extensions have been and are being developed by the software vendors and by the free Gnutella developers of the GDF. These extensions include intelligent query routing, [[SHA-1]] checksums, query hit transmission via [[User Datagram Protocol|UDP]], querying via UDP, dynamic queries via [[Transmission Control Protocol|TCP]], file transfers via UDP, [[XML]] metadata, source exchange (also termed ''the download mesh'') and parallel downloading in slices (swarming).<ref name="Dye, Mark p90"/>

There are efforts to finalize these protocol extensions in the Gnutella 0.6 specification, at the Gnutella protocol development website. The Gnutella 0.4 standard is outdated but it remains the latest protocol specification because all extensions, so far, exist as proposals. In fact, it is hard or impossible to connect today with 0.4 handshakes.  According to developers in the GDF, version 0.6 is what new developers should pursue using the [https://web.archive.org/web/20080724010901/http://gnet-specs.gnufu.net/ work-in-progress specifications].<ref>{{Cite web |title=Gnutella Protocol Development |url=http://rfc-gnutella.sourceforge.net/developer/index.html |access-date=2022-07-21 |website=rfc-gnutella.sourceforge.net |archive-date=2022-12-06 |archive-url=https://web.archive.org/web/20221206185124/https://rfc-gnutella.sourceforge.net/developer/index.html |url-status=live }}</ref>

The Gnutella protocol remains under development.  Despite attempts to make a clean break with the complexity inherited from the old Gnutella 0.4 and to design a clean new message architecture, it remains one of the most successful file-sharing protocols to date.<ref>{{cite thesis |last1=Tyson |first1=Gareth |date=2010 |title=A Middleware Approach to Building Content-Centric Applications |url=https://www.proquest.com/openview/e415473f53cf62814c2a9877ff59fa4b/1 }}{{pn|date=April 2025}}</ref>