Usenet News Services at Berkeley

Usenet News is a distributed worldwide discussion system, with different "newsgroups" that are categorized hierarchically based upon subject. Articles (or messages) are "posted" to these newsgroups by people connecting to a Usenet News server, which in turn broadcasts the message to other interconnected Usenet News servers.

The initial purpose of Usenet News was to provide a central repository for accessing discussions on a given topic--in contrast to mailing lists, which send a copy of a message to every person subscribed to the mailing list. People interested in a particular discussion topic can, with the appropriate news reader software on their own computer, connect to a Usenet News server and participate in the different newsgroups available there. Articles belonging to a particular newsgroup are propagated among Usenet sites, creating a network of sites which share common forums.

Two servers provide Usenet News for the Berkeley campus. Users connected to the campus network should use news.berkeley.edu (agate.berkeley.edu) for reading and posting of news. Users who wish to connect from outside the campus network may access the server authnews.berkeley.edu (geode.berkeley.edu) through the authenticated usenet service. The latter server requires an SSL encrypted connection and a valid CalNet ID.

Over the last few years, as the level of Internet usage in general has increased, so has Usenet traffic. There are more then 40,000 different Usenet newsgroups covering a wide variety of topics, languages, and specializations. Technical improvements in networks and news servers now guarantee that the vast majority of all Usenet articles arrive at major redistribution points within seconds of their having been posted, making Usenet virtually a "real-time" forum. These same changes have also been accompanied by some difficult obstacles for Usenet.

Foremost among these problems are the level of network traffic generated by Usenet services (a Usenet News server receiving all newsgroups now takes in an estimated 600-700 GB of data per day), and the drastic increase in the amount of "spam" (unsolicited commercial or bulk messages posted frequently or to an excessive number of newsgroups). It is estimated that spam articles, and "cancel" messages (messages requesting that an article be removed from Usenet circulation) now account for the majority of Usenet articles.

Spam filtering

One natural response to the increase in Usenet traffic is to filter incoming articles for spam. This has become common practice at most large Usenet sites, and CNS has had spam filters in place since October 1997. On average over 60,000 messages are rejected by the filter each day. Spam filtering resulted in better server performance, less network traffic, a reduction in server load for peering with other Usenet sites, and, most visible to users, fewer spam articles in newsgroups.

For more information on the details of the spam filter policy in use at UC Berkeley, refer to Usenet Spam Filter Policy [Draft].

Filtering requires that most messages be examined carefully with the results of several calculations used to determine if the message should be kept or discarded. The additional load filtering places on usenet servers along with the growing amount of usenet traffic has necessitated a division of labor among multiple servers. Two transit servers handle the exchange of messages with over 100 peer sites. These two servers also peer with the two servers described above which allow users to read and post messages.

The ucb.* and ucb.class.* hierarchies

One of the newsgroup hierarchies available on the campus news servers is the ucb.* hierarchy, which is dedicated to issues specific to the Berkeley campus. There are currently almost 400 different newsgroups within the ucb.* hierarchy, the most widely used being in the ucb.class.* hierarchy.

These "class" newsgroups groups are specifically for the discussion of class-related topics. Increasingly, the class newsgroups have become a critical tool for instruction outside of the classroom. In many cases, homework or other assignments can be distributed via a newsgroup, and the class newsgroups provide an easily accessible forum for students to exchange ideas and questions with instructors as well as other students.

For more information on how to request a newsgroup in the ucb.* or ucb.class.* hierarchies, please see Creating a Newsgroup at UC Berkeley.

Access to Usenet News service and distribution of the ucb.* newsgroups

Access to news.berkeley.edu for reading news and posting news articles is restricted by IP address to UC Berkeley students, faculty, and staff. Access from off campus is available through the authenticated usenet service. Also, because the ucb.* hierarchy is intended for postings from members of the campus community, campus news servers do not accept articles in the ucb.* hierarchy from external news servers.

Many other Usenet sites do carry the ucb.* newsgroups, and receive the articles posted to those newsgroups. In effect, this means that the ucb.* hierarchy is "read-only" outside of Berkeley. There are a few exceptions to this read-only policy, for example the ucb.alumni newsgroup, which is a group for topics related to Berkeley alumni, most of whom do not have access to campus news servers.

Another exception to the read-only status of the ucb.* newsgroups are the ucb.* email aliases available on agate.berkeley.edu, which have been created to forward an email message into a newsgroup posting. The email aliases are of the same format as the newsgroup, with the dots replaced by dashes, and "@agate.berkeley.edu" suffixed. An example would be the newsgroup ucb.class.cs61a, the class newsgroup for Computer Science 61A. Email sent to

ucb-class-cs61a@agate.berkeley.edu

would be forwarded into the ucb.class.cs61a newsgroup.

This document is an updated version of the 1998 BC&C article by Chris van den Berg Usenet News services at Berkeley.

Send comments to usenet@agate.berkeley.edu.