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The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Key Applications and Application Protocols            9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)                 9  Usenet (Network News) and the TCP/IP Network News Transfer Protocol (NNTP)                      9  TCP/IP Network News Transfer Protocol (NNTP)

NNTP Inter-Server Communication Process: News Article Propagation 1 2 3 4 NNTP Commands

Other Client-Server Functions

In addition to reading and posting, NNTP includes commands to support other “miscellaneous” tasks that a Usenet user may wish to perform. The client can ask the server for help information using the HELP command, or get a list of new newsgroups using the NEWGROUPS command, as described in the inter-server communication topic.

Most modern newsreaders include capabilities that go far beyond the basic posting and reading functions described above. Most maintain their own sets of configuration files that allow a user to maintain a set of favorite “subscribed” newsgroups, rather than having to choose a group to read from the master list each time Usenet is accessed. Newsreaders also keep track of which articles have been read by a user in each subscribed newsgroup, so one need not wade through a whole newsgroup to see new messages that have been posted.

One particularly useful enhancement to basic Usenet article reading is threading. This feature allows a newsreader to display articles not strictly in either alphabetical or chronological order, but rather grouped into conversations using the information in the articles' References headers. Threading is especially useful in busy newsgroups, as it allows you to see all the articles in a particular discussion at once, rather than trying to juggle messages from many conversations simultaneously.

A problem with threading is that it takes a long time for a newsreader to sift through all those References lines and construct the article threads. To speed up this process, many servers now cache extra threading or overview information for newsgroups, which can be retrieved by the client to save time when a newsgroup is opened. This is done using the XTHREAD or XOVER NNTP command extensions.

NNTP Inter-Server Communication Process: News Article Propagation 1 2 3 4 NNTP Commands