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How Usenet Works

The transmission of Usenet news is entirely cooperative. Feeds are generally provided out of good will and the desire to distribute news everywhere. There are places which provide feeds for a fee (e.g. UUNET), but for the large part no exchange of money is involved.

There are two major transport methods, UUCP and NNTP. The first is mainly modem-based and involves the normal charges for telephone calls. The second, NNTP, is the primary method for distributing news over the Internet. invisible.xbm invisible.xbm

With UUCP, news is stored in batches on a site until the neighbor calls to receive the articles, or the feed site happens to call. A list of groups which the neighbor wishes to receive is maintained on the feed site. The Cnews system compresses its batches, which can dramatically reduce the transmission time necessary for a relatively heavy newsfeed.

NNTP, on the other hand, offers a little more latitude with how news is sent. The traditional store-and-forward method is, of course, available. Given the "real-time" nature of the Internet, though, other methods have been devised. Programs now keep constant connections with their news neighbors, sending news nearly instantaneously, and can handle dozens of simultaneous feeds, both incoming and outgoing.

The transmission of a Usenet article is centered around the unique `Message-ID:' header. When an NNTP site offers an article to a neighbor, it says it has that specific Message ID. If the neighbor finds it hasn't received the article yet, it tells the feed to send it through; this is repeated for each and every article that's waiting for the neighbor. Using unique IDs helps prevent a system from receiving five copies of an article from each of its five news neighbors, for example.

Further information on how Usenet works with relation to the various transports is available in the documentation for the Cnews and NNTP packages, as well as in RFC-1036, the Standard for Interchange of USENET Messages and RFC-977, Network News Transfer Protocol: A Proposed Standard for the Stream-Based Transmission of News. The RFCs do tend to be rather dry reading, particularly to the new user. See section Requests for Comments for information on retrieving RFCs. invisible.xbm

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