Book Image

Understanding TCP/IP

By : CP Books a.s.
Book Image

Understanding TCP/IP

By: CP Books a.s.

Overview of this book

This book covers in detail the Open System Interconnection (OSI) reference model and the TCP/IP protocols that operate that different layers. Its coverage includes various application protocols. The authors explain in an easy-to-read style networking concepts and protocols, with examples that make the book a practical guide in addition to its coverage of theory.
Table of Contents (20 chapters)
19
Index

16.1 Message Format

The format of the contribution is specified by RFC 1036. The format is similar to an email message format except that there are even more header fields. Therefore, we will only be interested in header fields that are specific to contributions. They are as follows:

  • Path header field: This header field is analogous to the email ‘Received header’ field. While every mail server adds a new ‘Received header’ field at the beginning of the message, there is only one ‘Path header’ field. Names of news servers through which the message passes are added from the left and separated with an exclamation mark.

    PATH: news.nextra.cz!newsfeed1.online.no!nextra.com

    This means that the message went from the nextra.com server to the newsfeed1.o nline.no server and ended up on the news.nextra.cz server.

  • News group header field: This header field indicates the discussion group for which the messages are intended. For example:

    Newsgroup: alt.binaries...