Editing Gnutella2 (section)

== Differences from gnutella ==

Overall, the two networks are fairly similar, with the primary differences being in the packet format and the search methodology.

=== Protocol ===

Gnutella's packet format has been criticized because it was not originally designed with [[extensibility]] in mind, and has had many additions over the years, leaving the packet structure cluttered and inefficient.<ref name="Developer discussion of gnutella and Gnutella2 packet formats">{{cite web| url=https://groups.yahoo.com/group/the_gdf/message/16290| title=Developer discussion of Gnutella and Gnutella2 packet formats| publisher=The Gnutella Developer Forum| access-date=2006-05-15| archive-date=2023-01-17| archive-url=https://web.archive.org/web/20230117213155/https://www.yahoo.com/| url-status=dead}}</ref> Gnutella2 learned from this, and aside from having many of the added features of gnutella standard in Gnutella2, designed in future extensibility from the start.

=== Search algorithm ===

While gnutella uses a [[query flooding]] method of searching, Gnutella2 uses a [[random walk]] system, where a searching node gathers a list of Hubs and contacts them directly, one at a time. However, as Hub organize themselves in, so called, "Hub [[Computer cluster|clusters]]", where each Hub mirrors the information stored by its neighbors, the Leaf is returned the information of the entire Hub cluster (usually 7 Hubs). This has several advantages over the gnutella's query flooding system. It is more efficient, as continuing a search does not increase the [[network traffic]] [[Exponential function|exponentially]], queries are not routed through as many nodes, and it increases the [[granularity]] of a search, allowing a client to stop, once a pre-defined threshold of results has been obtained, more effectively than in gnutella. However, the walk system also increases the [[Complex network|complexity of the network]] and the [[Network management|network maintenance and management]] required, as well as requiring safeguards to prevent a [[cyberattack|malicious attacker]] from using the network for [[denial-of-service attack]]s.

=== Terminology ===

There is also a difference in terminology: while the more capable nodes, which are used to condense the network, are referred to as ''Ultrapeers'' in gnutella, they are called ''Hubs'' in Gnutella2, and they are also used slightly differently in topology. In gnutella, the Ultrapeers generally maintain as many leaves as peer connections, while Gnutella2 Hubs maintain far more leaves, and fewer peer (Hub-to-Hub) connections. The reason for this is that the search methods of the various networks have different optimum topologies.