PURPOSE OF THIS REPORTBefore gophers, hypertext, and sophisticated web browsers, telnet wasthe primary means by which computer users connected their machines with othercomputers around the world. Telnet is a plain ASCII terminal emulationprotocol that is still used to access a variety of information sources, mostnotably libraries and local BBS’s.
This report will trace the history and usageof this still popular and widely used protocol and explain where and how itstill manages to fit in today. HISTORY AND FUTURE OF TELNET”Telnet” is the accepted name of the Internet protocol and the commandname on UNIX systems for a type of terminal emulation program which allows usersto log into remote computer networks, whether the network being targeted forlogin is physically in the next room or halfway around the globe. A commonprogram feature is the ability to emulate several diverse types of terminals–ANSI, TTY, vt52, and more. In the early days of networking some ten to fifteenyears ago, the “internet” more or less consisted of telnet, FTP (file transferprotocol), crude email programs, and news reading. Telnet made library catalogs,online services, bulletin boards, databases and other network services availableto casual computer users, although not with the friendly graphic user interfacesone sees today. Each of the early internet functions could be invoked from the UNIXprompt, however, each of them used a different client program with its ownunique problems.
Internet software has since greatly matured, with modern webbrowsers (i. e. Netscape and Internet Explorer) easily handling the WWW protocol(http) along with the protocols for FTP, gopher, news, and email. Only thetelnet protocol to this day requires the use of an external program. Due to problems with printing and saving and the primitive look andfeel of telnet connections, a movement is underway to transform informationresources from telnet-accessible sites to full fledged web sites. However, itis estimated that it will still take several years before quality web interfacesexist for all of the resources now currently available only via telnet.
Therefore, knowing the underlying command structure of terminal emulationprograms like telnet is likely to remain necessary for the networkingprofessional for some time to come. ADVANTAGES AND DISADVANTAGES OF TELNETThe chief advantage to the telnet protocol today lies in the fact thatmany services and most library catalogs on the Internet remain accessible todayonly via the telnet connection. Since telnet is a terminal application, manysee it as a mere holdover from the days of mainframe computers and minicomputers. With the recent interest in $500 Internet terminals may foretell a resurgencein this business.
Disadvantages include the aforementioned problems that telnettends to have printing and saving files, and its primitive look and feel whencompared to more modern web browsers. OTHER APPROACHESThe functionality of the telnet protocol may be compared with the UNIX”rlogin” command, an older remote command that still has some utility today. Rlogin is a protocol invoked by users with accounts on two different UNIXmachines, allowing connections for certain specified users without a password. This requires setting up a “.
rhosts” or “/etc/hosts. equiv” file and may involvesome security risks, so caution is advised. Using telnet instead of the rlogin command will accomplish the sameresults, but the use of the rlogin command will have the effect of savingkeystrokes, particularly if it is used in conjunction with an alias. CONCLUSIONSome argue that the future of the Internet lies in sophisticated webbrowsers like Netscape and Internet Explorer, or tools such as Gopher that”save” end users from having to deal with the command line prompt and thepeculiar details of commands like Telnet. While that may be the case, thetendency remains in place for programmers to develop new software by building onthe old.
Therefore, knowing the underlying command structure of older protocolslike telnet and rlogin are likely to remain essential skills for the networkingprofessional in the forseeable future. Category: Technology