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Prof. Boerner's Explorations

Thoughts and Essays that explore the world of Technology, Computers, Photography, History and Family.


Archive for January 27th, 2010

Holocaust Day marked at Nazi death camp Auschwitz

RIP, Auschwitz, May you always be remembered and never repeated… During World War II, the Nazi forces sent European Jews and other ‘Undesirables’, were sent here to be sorted into those to be worked to death or gassed immediately. Those who remained alive were in tragic condition. But 65 years ago, the remaining inmates were liberated by the Allied Forces. A skeleton of the original camp remains today as an “eternal” memorial to those who were sacrificed there.

Let us reflect upon the culture that allowed such camps to exist and work to prevent it from happening again. Human life is worth more than that…


BBC News – Holocaust Day marked at Nazi death camp Auschwitz

Events have taken place at Auschwitz to commemorate the 65th anniversary of the liberation of the Nazi death camp, as the world marks Holocaust Memorial Day.

Elderly survivors gathered in freezing weather in Poland, where the camp was built under German occupation.

Israel’s prime minister and president urged that the Holocaust should never be forgotten, mourned its dead, and warned of a new danger posed by Iran.

More than a million people were murdered by the Nazis at Auschwitz.

The great majority were Jews but they also included non-Jewish Poles, Roma Gypsies and Soviet prisoners of war.

… [MORE]

Now that the iPad is here, what is it missing?

Plenty, according to this article. Many features of even netbooks are not available on the iPad and may not be available for quite a while since the iPad uses the iPhone OS, which is fairly limited… Is it taking a look, maybe, but there are a number of tablet computers set to enter the market later in the year…

For me, I call it a "wait and see"!


What’s Missing from the Apple iPad? 

Now that we know what the Apple iPad does do, and the lingering effects of the Steve Jobs Reality Distortion Field are starting to wear off a bit, let’s take a closer look at exactly what the iPad doesn’t do.

It does usher in a new computing form factor (or rather, revives it) — but it’s a space that will be awfully crowded in short order. Should you rush in to pick up the Apple-flavored tablet, or are there reasons to consider waiting for the series of devices that are sure to follow? For now, a quick look at what’s missing in the iPad version 1.0 might help decide the balance of your bank account at the end of March.

… [MORE]

Will the iPad really kill the Kindle?

I’m not sure that it will… This article presents 4 pro and 4 con arguments; but we need to consider what the true cost of each device is. The Kindle comes with an incredible battery, clear screen (with sizable type), and free 3G networking. Apple has always been notorious for its hidden costs. Just look at the basic iPhone cost for an average service plan ($150 a month). I’m sure that the iPad will also carry many hidden costs and not meet its performance expectations…

What do you think? Leave a comment for us to hear your take on this…


4 Reasons iPad Will Kill the Kindle, 4 Reasons It Won’t 

The Apple iPad burst onto the tech scene today in stunning full-color. Does that mean Amazon’s genre-defining and market-leading Kindle e-book reader is now dead?

“Uh-oh,” is the reaction we can imagine Amazon founder Jeff Bezos had when watching today’s unveiling of the eagerly awaited Apple iPad tablet. The new Apple device looks, at least upon first glance, like it will completely eat Amazon’s lunch. In fact, Steve Jobs even eulogized the Kindle in his unveiling.

“Amazon’s done a great job of pioneering this functionality with the Kindle. We’re going to stand on their shoulders and go a little further,” he said while unveiling the iPad’s iBook e-reader software. But is the Kindle really dead? Amazon proudly proclaimed the Kindle as the number one selling product on, with a huge banner on their home page today. Can it really be all over so fast?

Here are four reasons why the Kindle is dead, and four more why it might still have some life left in it.

… [MORE]

by Gerald Boerner


JerryPhoto_8x8_P1010031 Today’s profile examines the life and contributions of the controversial author and critic, Susan Sontag. She was a controversial author who wrote critically about war, especially the fighting in the former Yugoslavia units. She was also a critic of photography, writing On Photography which presented a different perspective on the images collected by most photographers. She was especially hard on the photojournalists claiming that when they could not find anything to photograph: the problem, according to Sontag, was they couldn’t find anything BAD to photograph!  GLB


“War is, first of all, noise. Incredible noise. In Sarajevo, it was like that– all the time. That sound– except– well, between three and five in the morning. Sometimes it– it would be silent.”
— Susan Sontag

“When photojournalists report that "there was nothing to photograph," what this usually means is that there was nothing terrible to photograph.”
— Susan Sontag

“Susan Sontag is not a photographer, yet her famous book ON PHOTOGRAPHY is required reading in almost every serious photography course in the world.”
— Bill Moyers

“The taste for futurology, or prophecy, is of at least equal importance. But this taste also confirms the prevailing unreality of the real historical past. Some novels which are situated in the past…”
— Susan Sontag

“We’re not animals. We’re not just people sheltering in our basements and standing on bread lines and water lines getting killed. You know people– when I came back people said, ‘Well who went to the theater?’ I said, "The same people that went to the theater before the war.”
— Susan Sontag

“I don’t think images can stop war, because I don’t think images just come all wrapped up with their meanings– very apparent to us. I think the images, as I say, they’ll disgust you with war in general, but they won’t tell you which of the wars, let’s say, that might be worth fighting…”
— Susan Sontag

“Well, they can– of course they can’t convey the totality. That goes without saying. No image can. But it’s also the– when you watch things through an image, it’s precisely affirming that you’re safe. Because you are watching it. You’re here and not there. And in a way you’re also– you’re– you’re innocent. You’re not doing it.”
— Susan Sontag

“As long as a particular disease is treated as an evil, invincible predator, not just a disease, most people with cancer will indeed be demoralized by learning what disease they have. The solution is hardly to stop telling cancer patients the truth, but to rectify the conception of the disease, to de-mythicize it.”
— Susan Sontag


The quotes included in this posting were taken from the public quotation sites which do not indicate that they are covered by any special copyright restrictions. Likewise, the images included in this posting were obtained under the Creative Commons Attribution-ShareAlike License from the web site which did not state any restrictions on their use. This blog makes every attempt to comply with the legal rights of copyright holders.

This posting is intended for the educational use of photographers and photography students and complies with the “educational fair use” provisions of copyright law. For readers who might wish to reuse some of these images should check out their compliance with copyright limitations that might apply to that use.



Susan Sontag (1933 – 2004)

susanSontag Susan Sontag was an American author, literary theorist, and political activist. She also wrote a perceptive essay on photography and was the companion of Anne Liebowitz for years.

Sontag, born Susan Rosenblatt, was born in New York City to Jack Rosenblatt and Mildred Jacobsen, both Jewish Americans. Her father ran a fur trading business in China, where he died of tuberculosis when Susan was five years old. Seven years later, her mother married Nathan Sontag. Susan and her sister, Judith, were given their stepfather’s surname, although he never formally adopted them.

Sontag grew up in Tucson, Arizona, and, later, in Los Angeles, where she graduated from North Hollywood High School at the age of 15. She began her undergraduate studies at Berkeley but transferred to the University of Chicago in admiration of its famed core curriculum. At Chicago, she undertook studies in philosophy and literature alongside her other requirements (Leo Strauss, Richard McKeon and Kenneth Burke were among her lecturers) and graduated with a B.A. She did graduate work in philosophy, literature, and theology at Harvard with Paul Tillich, Jacob Taubes and Morton White et al. After completing her Master of Arts in philosophy and beginning doctoral work at Harvard, Sontag was awarded a University Women’s Association scholarship for the 1957-1958 academic year to St Anne’s College, Oxford, where she had classes with Iris Murdoch, J. L. Austin, Alfred Jules Ayer, Stuart Hampshire and others. Oxford did not appeal to her, however, and she transferred after Michaelmas term of 1957 to the University of Paris. It was in Paris that Sontag socialised with expatriate artists and academics including Allan Bloom, Jean Wahl, Alfred Chester, Harriet Sohmers and Maria Irene Fornes. Sontag remarked that her time in Paris was, perhaps, the most important period of her life. It certainly provided the grounding for her long intellectual and artistic association with the culture of France.

susan At 17, while at Chicago, Sontag married Philip Rieff after a ten-day courtship. The philosopher Herbert Marcuse lived with Sontag and Rieff for a year while working on his book Eros and Civilization. Sontag and Rieff were married for eight years throughout which they worked jointly on the study Freud: The Mind of the Moralist that would be attributed solely to Philip Rieff as a stipulation of the couple’s divorce in 1958. The couple had a son, David Rieff, who later became his mother’s editor at Farrar, Straus and Giroux, as well as a writer in his own right.

The publication of Against Interpretation (1966), accompanied by a striking dust-jacket photo by Peter Hujar, helped establish Sontag’s reputation as "the Dark Lady of American Letters." Movie stars like Woody Allen, philosophers like Arthur Danto, and politicians like Mayor John Lindsay vied to know her. In the movie Bull Durham, her fictional writing was disparaged in a speech by the fictional Crash Davis to the fictional Annie Savoie in which Davis says he believes her novels are "over-rated, self-indulgent crap."

In her prime, Sontag avoided all pigeonholes. Like Jane Fonda, she went to Hanoi, and wrote of the North Vietnamese society with much sympathy and appreciation (see "Trip to Hanoi" in Styles of Radical Will). She maintained a clear distinction, however, between North Vietnam and Maoist China, as well as East-European communism, which she later famously rebuked as "fascism with a human face."

Tombe_de_Susan_Sontag_au_Cimetière_du_Montparnasse Grave of Susan Sontag

Sontag died in New York City on 28 December 2004, aged 71, from complications of myelodysplastic syndrome which had evolved into acute myelogenous leukemia. Sontag is buried in Montparnasse Cemetery, in Paris. Her final illness has been chronicled by her son, David Rieff.


Sontag’s literary career began and ended with works of fiction. After teaching philosophy and theology at Sarah Lawrence College, City University of New York and Columbia University under Jacob Taubes from 1960 to 1964, Sontag left academia and devoted herself to full-time writing. At age 30, she published an experimental novel called The Benefactor (1963), following it four years later with Death Kit (1967). Despite a relatively small output, Sontag thought of herself principally as a novelist and writer of fiction. Her short story "The Way We Live Now" was published to great acclaim on 26 November, 1986 in The New Yorker. Written in an experimental narrative style, it remains a key text on the AIDS epidemic. She achieved late popular success as a best-selling novelist with The Volcano Lover (1992). At age 67, Sontag published her final novel In America (2000). The last two novels were set in the past, which Sontag said gave her greater freedom to write in the polyphonic voice.

It was as an essayist, however, that Sontag gained early fame and notoriety. Sontag wrote frequently about the intersection of high and low art and the form/content dichotomy across the arts. Her celebrated and widely-read 1964 essay "Notes on ‘Camp’" was epoch-defining, examining an alternative sensibility to that which would see the best art in terms of its seriousness. It gestured towards and expounded the "so bad it’s good" concept in popular culture for the first time. In 1977, Sontag wrote the essay On Photography, which gave media students and scholars an entirely different perspective of the camera in the modern world. The essay is an exploration of photographs as a collection of the world, mainly by travelers or tourists, and the way we therefore experience it. She outlines the concept of her theory of taking pictures as you travel:

The method especially appeals to people handicapped by a ruthless work ethic – Germans, Japanese and Americans. Using a camera appeases the anxiety which the work driven feel about not working when they are on vacation and supposed to be having fun. They have something to do that is like a friendly imitation of work: they can take pictures.

Sontag suggested photographic "evidence" be used as a presumption that "something exists, or did exist", regardless of distortion. For her, the art of photography is "as much an interpretation of the world as paintings and drawings are", for cameras are produced rapidly as a "mass art form" and are available to all of those with the means to attain them. Focusing also on the effect of the camera and photograph on the wedding and modern family life, Sontag reflects that these are a "rite of family life" in industrialized areas such as Europe and America.

SONTAG reclined To Sontag "picture-taking is an event in itself, and one with ever more peremptory rights – to interfere with, to invade, or to ignore whatever is going on". She considers the camera a phallus, comparable to ray guns and cars, which are "fantasy-machines whose use is addictive". For Sontag the camera can be linked to murder and a promotion of nostalgia while evoking "the sense of the unattainable" in the industrialized world. The photograph familiarizes the wealthy with "the oppressed, the exploited, the starving, and the massacred" but removes the shock of these images because they are available widely and have ceased to be novel. Sontag saw the photograph as valued because it gives information but acknowledges that it is incapable of giving a moral standpoint although it can reinforce an existing one.

Sontag championed European writers such as Walter Benjamin, Roland Barthes, Antonin Artaud, E. M. Cioran, and W. G. Sebald, along with some Americans such as María Irene Fornés. Over several decades she would turn her attention to novels, film, and photography. In more than one book, Sontag wrote about cultural attitudes toward illness. Her final nonfiction work, Regarding the Pain of Others, re-examined art and photography from a moral standpoint. It spoke of how the media affects culture’s views of conflict.

A new visual code [Photography]

In her Essay On Photography Sontag says that the evolution of modern technology has changed the viewer in three key ways. She calls this the emergence of a new visual code.

On_Photography Firstly, Sontag suggests that modern photography, with its convenience and ease, has created an overabundance of visual material. As photographing is now a practice of the masses, due to a drastic decrease in camera size and increase of ease in developing photographs, we are left in a position where “just about everything has been photographed” (Sontag, Susan, (1977), On Photography 3). We now have so many images available to us of: things, places, events and people from all over the world, and of not immediate relevance to our own existence, that our expectations of what we have the right to view, want to view or should view has been drastically affected.

Arguably, gone are the days that we felt entitled of view only those things in our immediate presence or that affected our micro world; we now seem to feel entitled to gain access to any existing images. “In teaching us a new visual code, photographs alter and enlarge our notion of what is worth looking at and what we have the right to observe”. This is what Sontag calls a change in “viewing ethics”.

Secondly, Sontag comments on the effect of modern photography on our education, claiming that photographs “now provide most of the knowledge people have about the look of the past and the reach of the present”. Without photography only those few people who had been there would know what the Egyptian pyramids or the Parthenon look like, yet most of us have a good idea of the appearance of these places. Photography teaches us about those parts of the world that are beyond our touch in ways that literature can not.

susan-sontag-500 Sontag also talks about the way in which photography desensitizes its audience. Sontag introduces this discussion by telling her own story of the first time she saw images of horrific human experience. At twelve years old, Sontag stumbled upon images of holocaust camps and was so distressed by them she says “When I looked at those photographs something broke… something went dead, something is still crying”. Sontag argues that there was no good to come from her seeing these images as a young girl, before she fully understood what the holocaust was. For Sontag the viewing of these images has left her a degree more numb to any following horrific image she viewed, as she had been desensitized. According to this argument, “Images anesthetize” and the open accessibility to them is a negative result of photography.

Sontag examines the relationship between photography and reality. Photographs are depicted as a representation of realism. Sontag claimed that “such images are indeed able to usurp reality because first of all a photograph is not only an image, an interpretation of the real; it is also a trace, something directly stenciled off the real (Sontag, Susan (1982), The Image World 350). It is a resemblance of the real as the photograph becomes an extension of the subject. However, the role of the photograph has changed, as copies destroy the idea of an experience. The image has altered to convey information and become an act of classification. Sontag highlights the notion that photographs are a way of imprisoning reality- making the memory stand still.

Ultimately images are surveillance of events that trigger the memory. In modern society, photographs are a form of recycling the real. When a moment is captured it is assigned a new meaning as people interpret the image in their own manner. Sontag depicts the idea that images desensitize the real thing, as people’s perceptions are distorted by the construction of the photograph. However this has not stopped people from consuming images; there is still a demand for more photographs. Therefore, Sontag has impacted the audience’s understanding of reality, as photographs have adapted to a form of surveillance.

Susan Sontag brought out some uses of the photography, “Photography has become one of the principal devices for experiencing something, for giving an appearance of participation” (Sontag,1977), such as memorizing and providing evidence. She also states that “to collect photography is to collect the world.” (Sontag,1997)

Sontag believes that photography implies that we know about the world if we accept it as the camera records it. She states that photography has ‘become one of the principal devices for experiencing something, for giving an appearance of participation’. She refers to photographs as memento mori, where to take a photograph is to participate in another person’s mortality, vulnerability and mutability. The progression from the written word to capturing an image shifts the weight of the interpretation from the author to the receiver. Sontag believes however that ‘photographed images do not seem to be statements about the world so much as pieces of it, miniatures of reality that anyone can make or acquire’.

It is a slice in time and in effect, is more memorable than moving images for example, videos. It fills the gaps in our mind of the past and present. Even though photography has such effect, there are limits to photographic knowledge of the world. The limitations are that it can never be interpreted ethical or political knowledge. It will always be some kind of sentimentalism, whether cynical or humanist. Our modern day society can be described as a society feeding on aesthetic consumerism. There is an addiction and a need to constantly have reality confirmed and experiences enhanced by photographs.

Criticism and Acclaim

On Photography won the National Book Critics’ Circle Award for 1977 and was selected among the top 20 books of 1977 by the editors of the New Times Book Review.

In 1977, William H. Gass, writing in the New York Times, said the book "shall surely stand near the beginning of all our thoughts upon the subject" of photography.

In a 1998 appraisal of the work, Michael Starenko, wrote in Afterimage magazine that "On Photography has become so deeply absorbed into this discourse that Sontag’s claims about photography, as well as her mode of argument, have become part of the rhetorical ‘tool kit’ that photography theorists and critics carry around in their heads."

Sontag’s work is literary and polemical rather than academic. It includes no bibliography, and few notes. There is little sustained analysis of the work of any particular photographer and is not in any sense a research project as often written by Ph.D students. Many of the lesser reviews from the world of art photography that followed On Photography’ at the time of its publication were skeptical and often hostile, such as those of Colin L. Westerbeck and Michael Lesey.

In 2004 Sontag published a partial refutation of the opinions she espoused in On Photography in her 1994 collection of essay Regarding the Pain of Others. This book may be deemed as a postscript or addition to On Photography. Sontag’s publishing history includes a similar sequence with regard to her work Illness as Metaphor from the 1970s and AIDS and Its Metaphors a decade later, which included a revision of many ideas contained in the earlier work.

Private life

Sontag became aware of her attraction to women in her early teens and wrote in her diary aged 15, "so now I feel I have lesbian tendencies (how reluctantly I write this)." Aged 16, she had her first sexual encounter with a woman: "Perhaps I was drunk, after all, because it was so beautiful when H began making love to me …. It had been 4:00 before we had gotten to bed … I became fully conscious that I desired her, she knew it, too…."

In the early 1970s, Sontag was romantically involved with Nicole Stéphane (1923-2007), a Rothschild banking heiress turned movie actress. Sontag later engaged in a committed relationship with photographer Annie Leibovitz, with whom she was close during her last years; choreographer Lucinda Childs, writer Maria Irene Fornes, and other women.

In an interview in The Guardian in 2000, Sontag was quite open about her bisexuality:

"Shall I tell you about getting older?", she says, and she is laughing. "When you get older, 45 plus, men stop fancying you. Or put it another way, the men I fancy don’t fancy me. I want a young man. I love beauty. So what’s new?" She says she has been in love seven times in her life, which seems quite a lot. "No, hang on," she says. "Actually, it’s nine. Five women, four men."


Background and biographical information is from Wikipedia articles on:

Susan Sontag can be found at…

Susan Sontag: On Photography can be found at…

Also see…

Boston Review: An Interview with Susan Sontag

PBS NOW with Bill Moyers: Transcript: Susan Sontag — A Bill Moyers Interview…

by Gerald Boerner


JerryPhoto_8x8_P1010031 For each new computer breakthrough, an enabling technology is generally required. Before computers could become serious business machines, we needed ways of storing program instructions. Before we could work on major applications, such as accounting, we needed both long term storage mechanisms (Drum or Hard Disk) and Data Base Systems. Before we got microcomputers, we needed the microprocessor and high-capacity RAM chips. Today, we consider Packet Switching, the enabling technology for present-day networking.

Since today’s topic is much more challenging than some of the previous ones, we present some “lighter” quotes, many of which are “tongue in cheek”GLB


“Artificial Intelligence usually beats natural stupidity.”
— Anonymous

“If you don’t want to be replaced by a computer, don’t act like one…”
— Arno Penzias

“Remember, the problem is not that people are stupid; the problem is that modems are cheap.”
— Vince Sabio

“I sit looking at this damn computer screen all day long, day in and day out, week after week, and think: Man, if I could just find the ‘on‘ switch…”
— Zackary Good

“If computers had invented humans as part of a BI program (biological intelligence), humans would have been tossed aside as barely having achieved perfect game play at Tic-Tac-Toe.”
— Epine

“Science is supposedly the method by which we stand on the shoulders of those who came before us. In computer science, we all are standing on each others’ feet.”
— G. Popek

“Los Angeles County officials have asked that manufacturers, suppliers and contractors stop using the terms ‘master‘ and ‘slave‘ regarding computer hard drives, saying such terms are unacceptable and offensive. Additionally, the term ‘e-mail‘ will now be called ‘e-person letter‘, ‘dumb terminals‘ will now be ‘CPU-challenged monitors‘ and ‘Unix‘ will be referred to as ‘sexually dysfunctional operating system‘. Obviously, ‘fingering‘ is now banned entirely.”
— Kevin Fizz

“Reading, Pa., county controller Judith Kraines complained at a commissioners’ meeting in January about having to type letters and do other business on a typewriter because her computer was old and no one had been able to get it to work for two years. ‘If we had a computer‘, she said, ‘letters would go out faster‘. Three days later, she announced that the computer she was complaining about in fact had not been plugged in to any electrical outlet and that when the plug was inserted and the computer was turned on, it worked fine.”
— Anonymous

Wizards of the Internet: Packet Switching

Today’s topic is more technical than most of the others in this series. It is, however, a necessary exploration since packet switching is THE TECHNOLOGY that enabled ARPANet, the Internet, and our various Local Area Networks that allow us to connect the computers in our offices and homes together to share common resources. While Paul Barans has received most of the credit for this technique, Donald Davies (of the UK) also arrived at these principles at about the same time.

The interesting back story of on this development is found in Hafner and Lyons’ book, Where Wizards Stay Up Late. When ARPA was preparing to issues a Call for Proposals for ARPANet, all the major computer and telecommunications companies, including IBM, Burroughs, DEC, and At&T, were invited to a meeting to discuss the process. AT&T was the only company that showed up, but did so with about 100 of its best engineers. These technicians were there to tell ARPA how what they wanted, Packet Switching, was not technically possible.

The telephone companies, especially AT&T, had invested heavily in the Circuit Switching technologies that powered their nation-wide networks. These circuits, based upon a 64K “channel”, was dedicated to a single voice call. [We know that with today’s compression technologies, we can get equal or better quality from an 8K channel!] It was not about to abandon their investments in switches, wiring, or any other technologies to develop an alternative technology that could compete with them.

It’s ironic, isn’t it, that today the telecomm companies are, in fact, competing with Voice over IP (VOIP) — the precise situation that they feared! Just remember this every time that you use Vonage or Skype. Anyway, back to our story…

Just a final observation: This Packet Switching technology had to be combined with a second technology, Store and Forward, to make ARPANet work. In the coming days, we will explore this technology and the men behind it. So join me today in exploring Packet Switching…

packet-switching Packet switching is a digital network communications method that groups all transmitted data – irrespective of content, type, or structure – into suitably-sized blocks, called packets. Packet switching features delivery of variable-bit-rate data streams (sequences of packets) over a shared network. When traversing network adapters, switches, routers and other network nodes, packets are buffered and queued, resulting in variable delay and throughput depending on the traffic load in the network.

Packet switching contrasts with another principal networking paradigm, circuit switching, a method which sets up a limited number of dedicated connections of constant bit rate and constant delay between nodes for exclusive use during the communication session. In case of traffic fees, for example in cellular communication, circuit switching is characterized by a fee per time unit (per minute) of connection time, also when no data is transferred, while packet switching is characterized by a fee per unit of information (per Megabyte).

Two major packet switching modes exist; connectionless packet switching (also known as datagram switching) and connection-oriented packet switching (also known as virtual circuit switching). In the first case each packet includes complete addressing or routing information. The packets are routed individually, sometimes resulting in different paths and out-of-order delivery. In the second case a connection is defined and preallocated in each involved node before any packet is transfered. The packets includes a connection identifier rather than address information, and are delivered in order.

packet.switching Packet mode communication (or packet-oriented, packet-based) may be utilized with or without intermediate forwarding nodes (packet switches). In all packet mode communication, network resources are managed by statistical multiplexing or dynamic bandwidth allocation in which a communication channel is effectively divided into an arbitrary number of logical variable-bit-rate channels or data streams. Each logical stream consists of a sequence of packets, which normally are forwarded by the multiplexors and intermediate network nodes asynchronously using first-in, first-out buffering. Alternatively, the packets may be forwarded according to some scheduling discipline for fair queuing or for differentiated or guaranteed quality of service, such as pipeline forwarding or time-driven priority (TDP). Any buffering introduces varying latency and throughput in transmission. In case of a shared physical medium, the packets may be delivered according to some packet-mode multiple access scheme.


The concept of switching small blocks of data was first explored by Paul Baran in the early 1960s. Independently, Donald Davies at the National Physical Laboratory in the UK had developed the same ideas (Abbate, 2000).

Leonard Kleinrock conducted early research in queueing theory which would be important in packet switching, and published a book in the related field of digital message switching (without the packets) in 1961; he also later played a leading role in building and management of the world’s first packet switched network, the ARPANET.

Baran developed the concept of message block switching during his research at the RAND Corporation for the US Air Force into survivable communications networks, first presented to the Air Force in the summer of 1961 as briefing B-265 then published as RAND Paper P-2626 in 1962, and then including and expanding somewhat within a series of eleven papers titled On Distributed Communications in 1964. Baran’s P-2626 paper described a general architecture for a large-scale, distributed, survivable communications network. The paper focuses on three key ideas: first, use of a decentralized network with multiple paths between any two points; and second, dividing complete user messages into what he called message blocks (later called packets); then third, delivery of these messages by store and forward switching.

Baran’s study made its way to Robert Taylor and J.C.R. Licklider at the Information Processing Technology Office, both wide-area network evangelists, and it helped influence Lawrence Roberts to adopt the technology when Taylor put him in charge of development of the ARPANET.

Baran’s work was similar to the research performed independently by Donald Davies at the National Physical Laboratory, UK. In 1965, Davies developed the concept of packet-switched networks and proposed development of a UK wide network. He gave a talk on the proposal in 1966, after which a person from the Ministry of Defense told him about Baran’s work. A member of Davies’ team met Lawrence Roberts at the 1967 ACM Symposium on Operating System Principles, bringing the two groups together.

Interestingly, Davies had chosen some of the same parameters for his original network design as Baran, such as a packet size of 1024 bits. In 1966 Davies proposed that a network should be built at the laboratory to serve the needs of NPL and prove the feasibility of packet switching. The NPL Data Communications Network entered service in 1970. Roberts and the ARPANET team took the name “packet switching” itself from Davies’s work.

The first computer network and packet switching network deployed for computer resource sharing was the Octopus Network at the Lawrence Livermore National Laboratory that began connecting four Control Data 6600 computers to several shared storage devices (including an IBM Data Cell (2321) in 1968 and an IBM Photostore in 1970) and to several hundred ASR-33 Teletype terminals for time sharing use starting in 1968

Connectionless and connection-oriented packet switching

packetheader The service actually provided to the user by networks using packet switching nodes can be either connectionless (based on datagram messages), or virtual circuit switching (also known as connection oriented). Some connectionless protocols are Ethernet, IP, and UDP; connection oriented packet-switching protocols include X.25, Frame relay, Asynchronous Transfer Mode (ATM), Multiprotocol Label Switching (MPLS), and TCP.

In connection oriented networks, each packet is labeled with a connection ID rather than an address. Address information is only transferred to each node during a connection set-up phase, when an entry is added to each switching table in the network nodes.

In connectionless networks, each packet is labeled with a destination address, and may also be labeled with the sequence number of the packet. This precludes the need for a dedicated path to help the packet find its way to its destination. Each packet is dispatched and may go via different routes. At the destination, the original message/data is reassembled in the correct order, based on the packet sequence number. Thus a virtual connection, also known as a virtual circuit or byte stream is provided to the end-user by a transport layer protocol, although intermediate network nodes only provides a connectionless network layer service.

Packet switching in networks

4hosts2routers Packet switching is used to optimize the use of the channel capacity available in digital telecommunication networks such as computer networks, to minimize the transmission latency (i.e. the time it takes for data to pass across the network), and to increase robustness of communication.

The most well-known use of packet switching is the Internet and local area networks. The Internet uses the Internet protocol suite over a variety of Link Layer protocols. For example, Ethernet and frame relay are very common. Newer mobile phone technologies (e.g., GPRS, I-mode) also use packet switching.

X.25 is a notable use of packet switching in that, despite being based on packet switching methods, it provided virtual circuits to the user. These virtual circuits carry variable-length packets. In 1978, X.25 was used to provide the first international and commercial packet switching network, the International Packet Switched Service (IPSS). Asynchronous Transfer Mode (ATM) also is a virtual circuit technology, which uses fixed-length cell relay connection oriented packet switching.

Datagram packet switching is also called connectionless networking because no connections are established. Technologies such as Multiprotocol Label Switching (MPLS) and the Resource Reservation Protocol (RSVP) create virtual circuits on top of datagram networks. Virtual circuits are especially useful in building robust failover mechanisms and allocating bandwidth for delay-sensitive applications.

MPLS and its predecessors, as well as ATM, have been called “fast packet” technologies. MPLS, indeed, has been called “ATM without cells”. Modern routers, however, do not require these technologies to be able to forward variable-length packets at multigigabit speeds across the network.

X.25 vs. Frame Relay packet switching

packet-setup Both X.25 and Frame Relay provide connection-oriented packet switching, also known as virtual circuit switching. A major difference between X.25 and frame relay packet switching are that X.25 is a reliable protocol, based on node-to-node automatic repeat request, while Frame Relay is a non-reliable protocol, maximum packet length is 1000 bytes. Any retransmissions must be carried out by higher layer protocols. The X.25 protocol is a network layer protocol, and is part of the X.25 protocol suite, also known as the OSI protocol suite. It was widely used in relatively slow switching networks during the 1980s, for example as an alternative to circuit mode terminal switching, and for automated teller machines.

Frame relay is a further development of X.25. The simplicity of Frame relay made it considerably faster and more cost effective than X.25 packet switching. Frame relay is a data link layer protocol, and does not provide logical addresses and routing. It is only used for semi-permanent connections, while X.25 connections also can be established for each communication session. Frame relay was used to interconnect LANs or LAN segments, mainly in the 1990s by large companies that had a requirement to handle heavy telecommunications traffic across wide area networks. (O’Brien & Marakas, 2009, p. 250)

Despite the benefits of frame relay packet switching, many international companies are staying with the X.25 standard. In the United States, X.25 packet switching was used heavily in government and financial networks that use mainframe applications. Many companies did not intend to cross over to frame relay packet switching because it is more cost effective to use X.25 on slower networks. In certain parts of the world, particularly in Asia-Pacific and South America regions, X.25 was the only technology available.

Now, take a deep breath, count to ten, and exhale. You have made it through a progression of concepts that are challenging even for many graduate students. Tomorrow we continue our exploration of the developers of these technologies.



Katie Hafner & Matthew Lyon. (1998) Where Wizards Stay Up Late: The Origins of the Internet. Simon & Schuster

Background and biographical information is from Wikipedia articles on:

ARPANet can be found at…

The Internet can be found at…

Packet Switching can be found at…

Paul Baran can be found at…

Donald Davies can be found at…

Other Web Sites: What is… Packet Switching?

by Gerald Boerner


JerryPhoto_8x8_P1010031 Lincoln is known for his brilliant oratory. We all remember the brief, but powerful, Gettysburg Address. Today, we take a look at one of his speeches delivered in 1838 to a group of young men attending a lecture at the Young Men’s Lyceum: “The Perpetuation of Our Political Institutions”. In this speech, he supported the nation’s need to preserve a Reverence for the Law. He emphasized one of the keystones upon which this nation was founded. Let us reflect upon these principles anew; we need to constantly to hold these truths sacred.  GLB


“The way for a young man to rise, is to improve himself every way he can, never suspecting that any body wishes to hinder him.”
— Abraham Lincoln

“Upon the subject of education, not presuming to dictate any plan or system respecting it, I can only say that I view it as the most important subject which we as a people can be engaged in.”
— Abraham Lincoln

“With public sentiment, nothing can fail; without it nothing can succeed. Consequently he who moulds public sentiment, goes deeper than he who enacts statutes or pronounces decisions. He makes statutes and decisions possible or impossible to be executed.”
— Abraham Lincoln

“The true rule, in determining to embrace, or reject any thing, is not whether it have any evil in it; but whether it have more of evil, than of good. There are few things wholly evil, or wholly good. Almost every thing, especially of governmental policy, is an inseparable compound of the two; so that our best judgment of the preponderance between them is continually demanded.”
— Abraham Lincoln

“Let us discard all this quibbling about this man and the other man, this race and that race and the other race being inferior and therefore they must be placed in an inferior position. Let us discard all these things, and unite as one people throughout this land, until we shall once more stand up declaring that all men are created equal.”
— Abraham Lincoln

“We hope there is no sufficient reason. We hope all dangers may be overcome; but to conclude that no danger may ever arise, would itself be extremely dangerous. There are now, and will hereafter be, many causes, dangerous in their tendency, which have not existed heretofore; and which are not too insignificant to merit attention. …”
— Abraham Lincoln

“…we had a society in Springfield, which contained and commanded all the culture and talent of the place. Unlike the other one its meetings were public, and reflected great credit on the community … The address was published in the Sangamon Journal and created for the young orator a reputation which soon extended beyond the limits of the locality in which he lived.”
— William Herndon, Lincoln’s law partner

“As a nation, we began by declaring that “all men are created equal.” We now practically read it “all men are created equal, except negroes.” When the Know-Nothings get control, it will read “all men are created equal, except negroes, and foreigners, and catholics.” When it comes to this I should prefer emigrating to some country where they make no pretence of loving liberty — to Russia, for instance, where despotism can be take pure, and without the base alloy of hypocracy [sic].”
— Abraham Lincoln

Lincoln on Reverence for the Laws

AbrahamLincolnUltra Lincoln expected that America would become a nation doubtful about its heroes and its history. In his astonishing address to the Young Men’s Lyceum of Springfield, Ill., on Jan. 27, 1838, on “the perpetuation of our political institutions,” the 28-year-old Lincoln foresaw the inevitable rise in a modern democracy like ours of skepticism and worldliness. Indeed, he worried about the fate of free institutions in a maturing nation no longer shaped by a youthful, instinctive and (mostly) healthy patriotism.

Such a patriotism is natural in the early years after a revolutionary struggle for independence. To the generation that experienced the Revolution and the children of that generation, Lincoln explained, the events of the Revolution remained “living history,” and those Americans retained an emotional attachment to the political institutions that had been created. But the living memories of the Revolution and the founding could no longer be counted on. Those memories “were a fortress of strength; but what invading foemen could never do, the silent artillery of time has done; the leveling of its walls.” So, Lincoln concluded, the once mighty “pillars of the temple of liberty” that supported our political institutions were gone.

Lincoln_GettysburgAddress Lincoln implored his fellow citizens in 1838 to replace those old pillars with new ones constructed by “reason, cold, calculating, unimpassioned reason.” He knew that such a recommendation–such a hope–was problematic. In politics, cold, calculating reason has its limits. In the event, it was Lincoln’s foreboding of trouble, not his hope for renewal, that turned out to be correct. The nation held together for only one more generation. Twenty-three years after Lincoln’s speech, the South seceded, and civil war came.

Let every American, every lover of liberty every well-wisher to his posterity, swear by the blood of the Revolution, never to violate in the least particular the laws of the country, and never to tolerate their violation by others. As the Patriots of Seventy-six did to support of the Declaration of Independence, so to the support of the Constitution and laws, let every American pledge his life, his property, and his sacred honor. Let every man remember that to violate the law is to trample on the blood of his father,  and to tear the character of his own, and his children’s, liberty. Let reverence for the laws be breathed by every American mother to the listing babe that prattles on her lap. Let it be written in primers, spelling books, and in almanacs. Let it be preached from the pulpit, proclaimed in legislative halls, and enforced in courts of justice. And, in short, let it become the political religion of the nation; and let the old and the young, the rich and the poor, the grave and the gay, of all sexes and tongues, and colors and conditions, sacrifice unceasingly upon its alters.

The complete text of this speech, “The Perpetuation of Our Political Institutions,” can be found on the Teaching American History web site ( cited below.

Disney’s Adaptation

In the Disney’s “Great Moments with Mr. Lincoln” exhibit at the Disneyland Parks features the following speech on Liberty and the Reverence for Laws:

lincoln signlng The world has never had a good definition of the word liberty, and the American people, just now, are much in want of one. We all declare for liberty; but in using the same word we do not all mean the same thing.

What constitutes the bulwark of our liberty and independence? It is not our frowning embattlements, our bristling sea coasts. These are not our reliance against tyranny. Our reliance is in the love of liberty, which God has planted in our bosoms. Our defense is in the preservation of the spirit which prizes liberty as the heritage of all men, in all lands everywhere. Destroy this spirit, and you have planted the seeds of despotism around your own doors.

At what point shall we expect the approach of danger? By what means shall we fortify against it? Shall we expect some trans-Atlantic military giant to step the ocean and crush us at a blow? Never! All the armies of Europe, Asia, and Africa combined could not, by force, take a drink from the Ohio or make a track on the Blue Ridge in a trial of a thousand years.

At what point, then, is the approach of danger to be expected? I answer, [that] if it ever reach us, it must spring [from] amongst us; it cannot come from abroad. If destruction be our lot, we [ourselves must] be [the] author[s] and finisher[s]. As a nation of free men, we must live through all time[s], or die by suicide.

Great Moments with Mr. Lincoln at Disneyland Let reverence for the [law] be breathed by every American mother to the lisping babe that prattles on her lap; let it be taught in schools, in seminaries, and in colleges; let it be written in primers, [in] spelling-books, and almanacs; let it be preached from the pulpit, proclaimed in legislative halls, and enforced in courts of justice.

And, in short, let it become the political religion of the nation; and let the old and the young, the rich and the poor, the grave and the gay of all sexes and tongues and colors and conditions, sacrifice unceasingly [at] its altars. [And] let us strive to deserve, as far as mortals may, the continued care of Divine Providence, trusting that, in future national emergencies, He will not fail to provide us the instruments of safety and security.

Neither let us be slandered from our duty by false accusations against us, nor frightened from it by menaces of destruction to the Government nor of dungeons to ourselves. Let us have faith that right makes might, and in that faith, let us, to the end, dare to do our duty as we understand it.

The complete text of this original speech, “Address at a Sanitary Fair,” made by Lincoln can be found on the Teaching American History web site ( cited below. (Note that the differences between Lincoln’s speech and that used by Disney is indicated by the [..].)

Other Events on this Day
  • In 1785…
    Georgia becomes the first state to charter a state-supported university, the University of Georgia.
  • In 1838…
    Abraham Lincoln addresses the Young Men’s Lyceum in Springfield, Illinois
  • In 1880…
    Thomas Edison receives a patent for his electric incandescent lamp.
  • In 1888…
    The National Geographic Society is found in Washington, D.C.
  • In 1967…
    Astronauts Gus Grissom, Edward White, and Roger Chaffee die in a fire aboard their Apollo I spacecraft at Cape Canaveral, Florida.
  • In 1973…
    The Paris Peace Accords officially end the Vietnam War.

Dates and events based on:

William J. Bennett and John Cribb, (2008) The American Patriot’s Almanac Daily Readings on America. (Kindle Edition)

Background information is from Wikipedia articles on:

Great Moments with Mr. Lincoln can be found at…

Other Web Sites:

Time Magazine: Learning from Lincoln’s Wisdom can be found at…,9171,1630556,00.html#ixzz0dlxXS2n1

Lincoln’s Original “Address at a Sanitary Fair” can be found at…

Lincoln’s “The Perpetuation of Our Political Institutions” can be found at…