Az Internet fölfedezése

Az Internet megalkotása nem egyetlen feltaláló érdeme, hanem soké. A szakirodalom mégis megegyezik abban, hogy a néhány legnagyobb elgondolás közül talán a csomagkapcsolás (pocket switching) feltalálása volt a legdöntőbb. Bár a kifejezést Donald Davies alkotta meg (aki késve, 1965 novemberében jelentette be találmányát), a csomagkapcsolás bevezetését Paul Barannak tulajdonítják. Az alant következő visszaemlékezés szerint az ő közleménye 1964 májusában jelent meg (vagy ekkor hangzott el az IEEE kongresszusán, és később, de ezzel a dátummal tették közzé). Ugyanebben az évben kerültek – korlátozott – nyilvánosságra azok a belső jelentések, amelyeket Baran az előző években a RAND Corporation számára készített.

Ács Ernőnek az őáltala „address code”-nak nevezett eljárásra számos közleménye (így 1964-ben egy összefoglaló, nagy tanulmánya), sőt szabadalma volt. Az újdonságigény éve ez utóbbiakban: 1963. Azt állítom, hogy az Ács-féle „address code” lényegét tekintve azonos Paul Baran „distributed communications network”-jével, illetve Donald Davies „pocket switching”-jével.

A levéltári jellegű, eddig összegyűjtött bizonyítékokat a http://magyar-irodalom.elte.hu/gepesk/acserno/ könyvtárban helyeztük el. A kutatás a jövőben Képes Gábor egyetemi hallgató (ELTE Bölcsészettudományi Informatika Önálló Program) részvételével folytatódik.

Paul Baran visszaemlékezése David Hochfelder számára: a csomagkapcsolási eljárás felfedezésével kapcsolatos dátumok

Copyright-adatok:

INTERVIEW:

Paul Baran

INTERVIEWER:

David Hochfelder

DATE:

24 October 1999

PLACE:

Newark, New Jersey

Copyright Statement

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Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, Rutgers - the State University, 39 Union Street, New Brunswick, NJ 08901-8538 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

The term "packet switching" was first used by Donald Davies of the National Physical Laboratory in England who independently came up with the same general concept in November 1965. 16

Essentially all the basic concepts of today’s packet switching can be found described either in the 1962 paper 17 or in the August 1964 RAND Memoranda 18 in which such key concepts as the virtual circuit are described in detail.

The concept of the "virtual circuit" is that the links and nodes of the system are all free, except during those instances when actually sending packets. This allows a huge saving over circuit switching, because 99 percent of the time nothing is being sent so the same facilities can be shared with other potential users.

Then there is the concept of "flow control", which is the mechanism to automatically prevent any node from overloading. All the basic concepts were worked out in engineering detail in a series of RAND Memoranda (between 10 to 14 volumes, depending on how they are counted) 19  What resulted was a realization that the system would be extremely robust, with the end to end error rate essentially zero, even if built with inexpensive components. And, it would be very efficient in traffic handling in comparison to the circuit-switching alternative.

Később:

Most of the work was done in the period 1960-62.

Még később:

And, I felt that as I had completed the bulk of my work I began wrapping up the technical development phase in 1964 when I published the set of memoranda in 1964 which were primarily written on airplanes in the 1960 to 1962 era. There were some revisions in 1963, and the RAND Memoranda came out in 1964.

In May 1964 I published a paper in the IEEE Communications Transactions which summarizes the work and provides a pointer to each of a dozen volumes of Rand Memoranda for the serious reader who wanted to read the backup material. 22   Essentially all this work was unclassified in the belief that we would all be better off if the fate of the world relied on more robust communications networks. Only two of the first twelve Memoranda were classified. One dealt with cryptography and the other with weak spots that were discovered and the patches to counter the weak spots. A thirteenth classified volume was written in 1965 by Rose Hirshfield on real world geographical layout of the network. And there was a 14th describing a secure telephone that could be used with the system and had possible applications outside of the network and so wasn’t included in the number series. This was co-authored with Dr. Rein Turn.

Másokhoz való viszony:

But no matter how hard one tries, it seems that it is impossible to get the word out to everyone. This is not a novel problem. And, it contributes to duplicative research, made more common by the reluctance by some to take the time to review the literature before proceeding with their own research. Some even regard reviewing the literature as a waste of time. I was surprised many years later to find a few key people in closely related research say that they were totally unaware of this work until many years later. I recall describing the system in detailed discussions, only to find out at a later date that the listener had completely forgotten what was said, and who didn’t receive his Epiphany until much later and ostensibly through a different channel.

Később:

By 1963-4 I had completed most of my work on the packet switching technology

Arpanet: mit talált fel ő? Csak a pocket-switching-et (amit Ács Ernő is)

I have been embarrassed on occasion by people improperly giving me credit for creating the ARPANET. Of course I did not create the ARPANET or the Internet. Yes, I did seem to have invented packet switching as far as I can tell. And, yes, packet switching was used in the ARPANET and in the Internet. And, yes, packet switching did give the Internet some of its novel properties. But I only did this one piece of the underlying technology. Another person [Davies] came along later and independently came up with much of the same stuff , so I don’t feel that I deserve any excessive credit.

Elsőbbség-kérdés: Baran véleménye saját szerepének viszonylagosságáról

In any field no one never starts from scratch. There are always predecessor activities that form the foundation for later work. Vol. V of the ODC series attempted to describe all known (by me) alternative approaches suggested up to 1963.

Hochfelder:  Is this (Vol. V) a RAND publication?

Baran:

Yes. It is one of the ODC series on line at the RAND web site. I believe that anyone contemplating research in a field should always first review the literature in that field, particularly if being paid by taxpayer funds. This minimize research that duplicates prior work and why Vol. V was written. While Vol. V list relevant work going on up to the 1963 cutoff date, I am afraid that there are gaps in the literature from about that period up to the early start of the ARPANET which is excellently documented.

I vaguely recall work in Canada and Japan that doesn’t seem to have made it into widely available literature. I don’t recall the details. Maybe it will be lost in history.

Első publikációja:

My first publication outside of RAND about packet switching was a 1964 paper published in the Transactions of the Communications Society.