Published July 12, 2000
So you are handy with email and can browser the Web; ah, but there’s much more. Telnet, for instance, places you at the keyboard of other computers anywhere in the world on the Internet.
It may seem like stepping backward to favor simulating the old fashioned computer terminal instead of the familiar but sedentary point-n-click graphical user interface (GUI). Connection to mainframes and other mini- and micro-computers has valuable uses.
Some resources on the Internet are still best accessed by the command line. You type the commands yourself using a program like Telnet, made by the National Center for Supercomputing Applications. Telnet links your computer to another as if you were at that keyboard miles or continents away. The commands you type are instructions to that remote computer.
Because of the vast interconnections of networks, Telnet can be used to route around slow (netlag) or nonfunctioning portions of the networks, or many other things. Some Internet Service Providers allow Telnet, sometimes referred to as a shell account.
Remotely linking one computer to another, or a string of them, utilizes the unique design characteristic of the Internet. This lessens the cost of long distance charges to call home directly.
The potential inadvertent or deliberate misuse of Telnet to a security-conscious service provider might be regarded as tampering. Unrestricted access by the novice Telneter is a frightful abhorance to some system’s administrator to approve your request just because you think it’s neat. Remember, location doesn’t matter on the Net. Find another.
Universities often accept public users to Telnet; so do the US Naval Observatory and Education Resources Info Center. They will issue a username and password, or perhaps provide restricted privileges through one of their own. Not all information is available from the World Wide Web.
Technically, Telnet is a protocol, or set of instructions for computers to share information. The Internet is littered with protocols, the universal pattern for signal interaction. If both the client (you) and the server (them) are on the same frequency, so to speak, informational exchange will transcend any computer type or operating system in use on either end.
Many of us travel extensively for business or recreation. A long distance phone call is avoidable. Instead Telnet there from any Internet access location (dialup or permanently-on computer). Retrieve email, read the latest UseNet newsgroups or execute (launch/run) a program on that other computer via Telnet.
Before point-n-click GUI, most of the automated computing in the world was performed on central processing mainframe machines the size of a warehouse. Many people doing useful work simultaneously meant each had their own dumb terminal, which is simply a keyboard and screen.
Among manufacturers, terminals were functionally identical for any of the majors like IBM, Honeywell and Burrows. Digital Equipment Company (DEC) made VT100 and VT220 terminals, names used like we colloquially refer to Kleenex as facial tissue.
Computers now, as then, still reach into these working Goliath’s using a program to emulate the dumb terminals. The operator types words or character sequences that command the remote machine to respond in a known way.
Telnet is lots of content but no dazzle. Weather bureaus and Bulletin Board Systems (BBS) are open to information retrieval, file downloads, using Telnet. The card files of the Library of Congress are on the Internet via Telnet.
A useful inquiry process of Telnet is tracking and verifying the network paths. For instance, typing ping and then the host name will return an echo from that computer measuring the small fraction of a second for the round trip.
Another query, whois and then the host name will return a response from Internic.net, the repository of domain names that end in .com and .net. The registered owner’s name and postal mailing address is given, very handy if wanting to know where in the world is google.com.
Similarly, typing traceroute followed by the destination address will result in a return list of all routers’ addresses between that destination and the Telnet remote server. The shorter the pathway, usually the more reliable is the connection. If the Net is down along one circuit, another will automatically be rerouted. The path adjusts to the networked traffic.
When (not if) you’re stuck and want help, type HELP on the command line. Also, typing MAN will return a list of instructional topics in the manual which can be printed and studied later. Don’t be reluctant; it’s all there for you, another corner of the vast and growing Internet.