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Of Packets and Freight Trains
Of Packets and Freight Trains
Packet switchinglowers the cost of computer communications nets and information services, making it possible for you to send 1,000 words coast to coast for as little as $1.The technique, developed by the military, lets many machines jabber away at once on the same phone line.To tap into a packet-switching net, you typically dial local numbers or 800 ones reachable nationally. Giant networks like Telenet and MCI Mail use many different phone lines, but that’s still a fraction of what they’d need without packet switching.Just imagine each of the nets’ phone lines as a rail line. Many trains (packetsspecifying the starts and ends of extrabrief computer transmissions) can zip over the tracks at once if you keep them from crashing into each other. The trains carry freight (bits and bytes of information). Electronic labels assure that the cargo reaches the right destinations (the gizmos that forward the information over the phone line to the receiving computers).Naturally, the use of common trains and rail lines (apacket-switching network) is more efficient than replicating the arrangement for each cargo recipient (each computer).This explanation, though simplified, sums up the technique according to Vinton G. Cerf, a top packet-switching expert.Incidentally, packet-switchingtechniquestechniquescan also increase the efficiency of networks connecting computers in the same office.
Packet switchinglowers the cost of computer communications nets and information services, making it possible for you to send 1,000 words coast to coast for as little as $1.
The technique, developed by the military, lets many machines jabber away at once on the same phone line.
To tap into a packet-switching net, you typically dial local numbers or 800 ones reachable nationally. Giant networks like Telenet and MCI Mail use many different phone lines, but that’s still a fraction of what they’d need without packet switching.
Just imagine each of the nets’ phone lines as a rail line. Many trains (packetsspecifying the starts and ends of extrabrief computer transmissions) can zip over the tracks at once if you keep them from crashing into each other. The trains carry freight (bits and bytes of information). Electronic labels assure that the cargo reaches the right destinations (the gizmos that forward the information over the phone line to the receiving computers).
Naturally, the use of common trains and rail lines (apacket-switching network) is more efficient than replicating the arrangement for each cargo recipient (each computer).
This explanation, though simplified, sums up the technique according to Vinton G. Cerf, a top packet-switching expert.
Incidentally, packet-switchingtechniquestechniquescan also increase the efficiency of networks connecting computers in the same office.
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Even now, if you can pin down your topic by name, you can pay next to nothing to use electronic data banks and similar services on occasion. You needn’t even cough up a fat subscription fee. Through MCI Mail—$18-a-year basic charge—you can use the Dow Jones News/Retrieval Service. It’s one way to watch companies of interest. Regularly, during the writing of this book, Iwould ask Dow what Kaypro was up to. I merely typed “.KPRO” and a carriage return, and the computer spewed out the latest Kaypro news; even at 300 baud the bulletins took less than a minute or so to reach me. My cost? Maybe forty cents a shot. Just before Ballantine wanted the final version of this manuscript, I learned of stockholders suits against the Kaypro—facts that I might not have known in time without the Dow Jones wire.
My experience illustrates the speed with which the information services can update their indexes and articles.
TheNew York Timesindex at your local library, for instance, may be weeks out of date. Without a computerized search you’d better either read “All the News That’s Fit to Print” every day or be willing to flip through perhaps a month’s worth of papers.
You can even read condensed articles daily from major papers on line—long before they thud against your door, which they may never do if they’re in cities a continent away. CompuServe offers theWashington Post, for instance, among others, plus the Associated Press, the major American wire service. The Source flashes bulletins from United Press International. And there are electronic editions of specialized publications like theU.S. News Washington Letter.
“Buy stocks now,” theLetter’s first electronic edition said presciently in 1982.
“The very next day, August 17,” gloated a news release from The Source, “the stock market went through the roof.”
Not surprisingly, big newspaper and magazine companies are tinkering with electronic information services. Often, rather than home computers, the services use Teletext (using cable television lines or broadcastTV) or Videotex (phone lines).
Of course lines may fuzz between technologies. Television-based systems are growing cheaper; and someday your portable TV may have a built-in computer, a socket for a keyboard, and a flat, high-resolution screen fit for word processing and electronic mail. Call it a Vu-Write. Make it a first-class color television. But also a computer suited for clerks and professionals alike. Give it a memory system less quirky than floppy disks. Develop idiot-proof software selected by simple switches. Mass-produce a Selectric-style keyboard, detachable, or, eventually, a good voice recognizer. Throw in artificial speech, too, once it’s perfected, and include a built-in, high-speed modem or the equivalent. Sell the Vu-Write for $200 at the local Sears. Or perhaps to companies who can recruit clerical telecommuters by in effect offering free TVs.
Somewhere in Silicon Valley, a savvy company may be at workon a Vu-Write now; and if it succeeds, maybe mass telecommuting will be with us sooner than anyone thought.
No matter what, Vu-Write or not, energy crisis or not, think about telecommuting and related innovations before your competitors do. One intelligent step would be the use of electronic mail where appropriate.
Backups:
Backups:
◼XI, The Micro Connection: Some Critical Explanations, page349.
◼XII, MODEM7: An Almost Free and Fairly Easy Way to Talk to Other Computers, page354.
◼XIII, Why Not an Electronic Peace Corps?, page366.