an) Speakers of languages other than English will recognize the roots of these words; Reto, for example, is similar to the Spanish word red Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Protocols Chapter 2 (network). A pretty good Esperanto-English dictionary can be found at http://esperanto-panorama.net/vortaro/eoen.htm. So what does this have to do with telecommunications and the trans- mission of e-mail messages? Read on. Layer Seven: The Application Layer The network user's application (Eudora, Outlook, Outlook Express, PROFS, etc.) passes data down to the uppermost layer of the OSI Model, called the Application Layer. The Application Layer provides a set of highly specific services to the application above it that have to do with the meaning or semantic content of the data. These services include, among others, file transfer, remote file access, terminal emulation, net- work management, mail services, and data interoperability. This inter- operability is what allows our PC user and our mainframe-based user to communicate: The Application Layer converts the application-specific information into a common, "canonical" form that can be understood by both systems. A canonical form is a form that can be understood univer- sally. The word comes from "canon," which refers to the body of officially established rules or laws that govern the practices of a church. The word also means an accepted set of principles of behavior that all parties in a social or functional grouping agree to abide by. Hence, the applicability of Esperanto. Now let's examine a real-world example of a network-oriented canon- ical form. When network hardware manufacturers build components-switches, multiplexers, cross-connect systems, modem pools-for sale to their cus- tomers, they do SO knowing that one of the most important aspects of a successful hardware sale is the i