1.1. What is Usenet?

Usenet (often referred to as "News" or "Newsgroups") is a very large distributed text conferencing system currently in use on the Internet. The underlying concept of Usenet is simple: one person posts an article to a newsgroup on a local news server. The local server archives the article and sends it to a news hub which routes the article to other hubs and servers. This process continues until all interconnected news systems have received a copy of the article.

Usenet servers and hubs operate using the Internet RFC-977 and RFC-2980 defined NNTP (Network News Transport Protocol). News systems use NNTP to implement a "flood-fill" algorithm to route news articles. Using NNTP, news systems offer articles to peer systems. If an article has already been seen by a local system, the article is refused when offered by a remote system. In this way, having multiple interconnected peer news systems promotes reliability and high performance.

Usenet traffic at major hubs and servers can exceed 2,000,000 articles per day and continues to grow at an brisk pace. The task of maintaining a reliable, high-performance Usenet network is becoming increasingly difficult.