<html><head></head><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:13px"><div dir="ltr" id="yui_3_16_0_ym19_1_1472616023279_177656">In case people are interested, various packet radio efforts did actually have demos for the military that utilized a hummer or an Air Force airplane besides the SRI bread/mobile van which is now sitting outside the Computer History Museum. I am not aware of any packet radio demos with helicopters. I think power, weight, size issues probably prevented this but feel free to correct if anyone knows otherwise. Helicopters have been used in more recent MANET program demos for DARPA. <br></div><div id="yui_3_16_0_ym19_1_1472616023279_178028" dir="ltr"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1472616023279_176409"><span id="yui_3_16_0_ym19_1_1472616023279_177605">barbara</span></div><div id="yui_3_16_0_ym19_1_1472616023279_181542" dir="ltr"><span id="yui_3_16_0_ym19_1_1472616023279_177605"><br></span></div><div id="yui_3_16_0_ym19_1_1472616023279_181700" dir="ltr"><span id="yui_3_16_0_ym19_1_1472616023279_177605">p.s.</span></div><div id="yui_3_16_0_ym19_1_1472616023279_181624" dir="ltr"><span id="yui_3_16_0_ym19_1_1472616023279_177605">Packet radios may have ended up on a boat too before I started working on the project. I believe SRI had access to a research vessel.<br></span></div><div id="yui_3_16_0_ym19_1_1472616023279_181623" dir="ltr"><span id="yui_3_16_0_ym19_1_1472616023279_177605"><br></span></div><div id="yui_3_16_0_ym19_1_1472616023279_176087" class="qtdSeparateBR"><br></div><div style="display: block;" id="yui_3_16_0_ym19_1_1472616023279_176252" class="yahoo_quoted"> <div id="yui_3_16_0_ym19_1_1472616023279_176251" style="font-family: times new roman, new york, times, serif; font-size: 13px;"> <div id="yui_3_16_0_ym19_1_1472616023279_176250" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1472616023279_176249" dir="ltr"> <font id="yui_3_16_0_ym19_1_1472616023279_176253" face="Arial" size="2"> <hr id="yui_3_16_0_ym19_1_1472616023279_176528" size="1"> <b><span style="font-weight:bold;">From:</span></b> "internet-history-request@postel.org" <internet-history-request@postel.org><br> <b><span style="font-weight: bold;">To:</span></b> internet-history@postel.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Wednesday, August 31, 2016 3:35 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> internet-history Digest, Vol 105, Issue 37<br> </font> </div> <div id="yui_3_16_0_ym19_1_1472616023279_176415" class="y_msg_container"><br>Send internet-history mailing list submissions to<br> <a id="yui_3_16_0_ym19_1_1472616023279_181485" ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br> <a id="yui_3_16_0_ym19_1_1472616023279_182371" href="http://mailman.postel.org/mailman/listinfo/internet-history" target="_blank">http://mailman.postel.org/mailman/listinfo/internet-history</a><br>or, via email, send a message with subject or body 'help' to<br> <a id="yui_3_16_0_ym19_1_1472616023279_181486" ymailto="mailto:internet-history-request@postel.org" href="mailto:internet-history-request@postel.org">internet-history-request@postel.org</a><br><br>You can reach the person managing the list at<br> <a ymailto="mailto:internet-history-owner@postel.org" href="mailto:internet-history-owner@postel.org">internet-history-owner@postel.org</a><br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of internet-history digest..."<br><br><br>Today's Topics:<br><br> 1. Why TCP? (Jack Haverty)<br> 2. Re: Why TCP? (Vint Cerf)<br> 3. Re: Why TCP? (Brian E Carpenter)<br> 4. Re: Why TCP? (Vint Cerf)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Wed, 31 Aug 2016 14:43:24 -0700<br>From: Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>><br>Subject: [ih] Why TCP?<br>To: <a ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a><br>Message-ID: <<a ymailto="mailto:87d2d00a-361a-8ec1-b1cd-2e047a40df93@3kitty.org" href="mailto:87d2d00a-361a-8ec1-b1cd-2e047a40df93@3kitty.org">87d2d00a-361a-8ec1-b1cd-2e047a40df93@3kitty.org</a>><br>Content-Type: text/plain; charset=utf-8; format=flowed<br><br>[I changed the subject because I hate unsearchable subjects like <br>"...internet history digest..."]<br><br>I think Dave's observation is a really important fact for future <br>historians - the Internet did not evolve in a vacuum.<br><br>ARPANET was one of the first packet networks (I'll let others argue <br>about which was First...), but it was preceded by networks based on <br>phone lines and modems interconnecting terminals and computers.<br><br>The ARPA Packet Radio net enabled communications between mobile <br>computers, moving around in jeeps and helicopters, by radio links. But <br>it was preceded by AlohaNet in Hawaii, which interconnected the various <br>islands by radio. AlohaNet was also the inspiration for Ethernet. In <br>the early 1970s, Bob Metcalfe's office at MIT was three doors down the <br>hallway from mine as he wrote his thesis that spawned Ethernet. I <br>remember hearing about AlohaNet from him.<br><br>Later, SATNET interconnected sites using satellite links, also obviously <br>using radio for communications. Unlike the packet radio environment, <br>the path of the satellites was highly predictable, and the massive dish <br>antennas on the ground didn't move at all.<br><br>SATNET was subsequently adapted to create MATNET, a Navy project, that <br>used satellite dishes on ships for communication. Ships moved of <br>course, but not as rapidly or spasmodically as jeeps and aircraft.<br><br>Ethernet was evolved by Xerox PARC into its own "internet", with <br>multiple LANs interconnecting by radio links or telephone lines. <br>During the early 80s, The Internet which we still use today was running <br>in parallel with the PARC internet (I can't recall what they called it), <br>using PUP where we used TCP.<br><br>As Dave noted, we got used to hearing that the mission of the Internet <br>Project (as driven by the IAB/ICCB under Vint's direction) was to <br>develop the infrastructure technology, i.e., protocols and algorithms <br>and standards, to interconnect these networks, both the existing types <br>and anything else that someone might dream up in the future.<br><br>If some new type of network could carry packets from point A to point B, <br>it should be possible to incorporate it into the Internet --- without <br>requiring the host computers to change any software (which would be <br>hard), or change all of the routers in the Internet (only the ones that <br>directly interface to the new network need to change to be able to use it)<br><br>We even mused about extreme networking. For example, TCP/IP should be <br>able to utilize a "network" implemented using carrier pigeons for <br>transport, with each pigeon carrying a small tube with a strip of paper <br>containing one packet of data.<br><br>As far as I know, no one ever did that.... But it was one of the <br>scenarios that came up in the brainstorming discussions to prevent us <br>from changing the technical mechanisms in a way that precluded <br>PigeonNet's use.<br><br>On another extreme, we mused about incorporating another Internet into <br>The Internet, i.e., using some existing set of routers and lines <br>(Internet 1), as a means to interconnect routers in an overlaid internet <br>(Internet 2). After all, a fragment of an internet meets the <br>definition of a network - a communications mechanism that can carry packets.<br><br>As far as I know, such multi-layer Internet-of-Internets *did* happen. <br>It was used in some secure environments and I think also used as a <br>technique to implement the IP4 to IP6 transition (are we there <br>yet...it's been more than 30 years!???)<br><br>So, as Dave noted, TCP/IP was developed as an overlay that would run <br>over all existing, or future, networks. That goal often came up during <br>the meetings and discussions as something akin to a Prime Directive.<br><br>==============<br><br>IMHO, future historians might also like to know *why* that was the Prime <br>Directive. In other words, Why TCP? The intransigence of people to <br>settle on a single technology and protocol was important as a motivator, <br>but IMHO only part of it.<br><br>My introduction to TCP was in 1977. I had been working in the ARPANET <br>environment, doing things like email et al at MIT. I moved to BBN in <br>1977 and my first task was to write the first TCP for Unix, which was <br>needed as part of an ARPA project. At that time, TCP was at the version <br>2.5 stage.<br><br>Over the next year or so, we made a lot of changes to create TCP 3 and <br>then TCP 4.<br><br>Creating a technology that could incorporate any kind of network was a <br>big part of the mission. But there were others. For example, it was <br>desirable that the infrastructure support different types of user <br>traffic. Ideally, the TCP infrastructure would support all types of <br>user traffic in a way similar to its ability to utilize any type of <br>network that might appear.<br><br>Specifically, voice traffic - realtime human-human speech - was found to <br>not work very well over a TCP connection. With our traditional uses, <br>e.g., FTP/Telnet/Email, getting all of the data there intact was the <br>overriding goal. In speech, getting the data there in a timely fashion <br>was most important, and some loss of snippets of speech was acceptable.<br><br>That, among other things, motivated the split of TCP into TCP/IP, <br>allowing the creation of UDP and "higher" protocols to carry things like <br>speech and video.<br><br>=======================<br><br>All of these internet-history discussions tend to revolve around <br>technology - protocols, algorithms, etc., which isn't surprising since a <br>lot of the people on this list were deeply involved in creating that <br>technology.<br><br>But for the benefit of historians, there's another "layer" of discussion <br>that seems important - Why TCP? In other words, why was it so important <br>to create a whole new infrastructure with such capabilities.<br><br>The Departments of Defense (note plural) put quite a lot of money into <br>the efforts to develop the Internet technology. ARPA, part of the US <br>military, was a large player, acting as a conduit for funds from the <br>various parts of the military - Army, Navy, Air Force, etc. But other <br>players from other countries were there too - RSRE (UK), NDRE (Norway), <br>DFVLR (Germany), and CNUCE (Italy) are ones I remember.<br><br>So, .... the interesting question is "Why did they send money, and keep <br>sending it, to create the TCP/IP technology"? Why did they care about <br>being able to interconnect all sorts of networks?<br><br>The answer of course is because they needed it to solve their own <br>communications problems.<br><br>During that TCP2-->4 evolution period, I remember that we were <br>continuously aware of stereotypical military scenarios in which TCP was <br>supposed to operate. The military folks didn't really care about bits, <br>bytes, packets, etc. They just knew what they wanted to be able to do <br>with it all.<br><br>The scenario I remember most was what I heard on joining the fray in <br>1977 and learning what exactly this "TCP" thing and associated projects <br>were all about.<br><br>It was a "Command and Control" scenario, which is the bread-and-butter <br>of the military world. The notion was that someone "out in the field", <br>perhaps a scout in a jeep, would see something interesting, and need to <br>report it up the command chain. "I see a column of tanks coming along <br>the river valley".<br><br>The jeep of course couldn't be wired into an IMP port on the ARPANET. <br>But it could have a radio, and that radio should be able to communicate <br>with another jeep, or tank, or whatever else might be around. And they <br>might be able to communicate with the field headquarters, possibly <br>several miles away. But everyone had to be able to move, often rapidly <br>and unpredictably.<br><br>So, .... here's some money....make it work... and Packet Radio networks <br>were born.<br><br>With lots of jeeps, or helicopters, or whatever, and their eyes and <br>ears, the field headquarters could be connected back to the Pentagon <br>over the ARPANET and all of that information could be used to figure out <br>what to do about it. But somehow we need to have messages flow from the <br>Packet Radio to the ARPANET...<br><br>So, .... here's some money....make it work.... and gateways (aka <br>routers) were born.<br><br>Back at the Pentagon, looking at all the reports, it might become clear <br>that the Army guys in the jeeps needed a little help as waves of tanks <br>approached them.<br><br>Perhaps there's a ship offshore, with some big guns, and a carrier full <br>of nasty airplanes. But they're over the horizon, too far away for the <br>Packet Radio to reach, or for wires to an IMP port. But they do have <br>satellite dishes, and can talk to other dishes halfway around the planet <br>if necessary. If only their computers could talk with everybody else...<br><br>So, here's some money....make it work.... and SATNET and MATNET were <br>born. The USS Carl Vinson was on The Internet.<br><br>When things get frenetic, messages and email just aren't fast enough. <br>Real time voice communication is critical (remember, no cell phones in <br>those days). But voice over TCP isn't working well.<br><br>So, here's some money....make it work.... and TCP is split into TCP and <br>IP, UDP is defined, and the obstacle to realtime voice is removed. Hey, <br>it should even work for video someday.<br><br>We can't do video, but graphics are a big help. A general might be able <br>to view a map while talking with commanders in the field who see the <br>same map. Even use a pointer to highlight specific areas of the map as <br>he gives instructions. "Unit A, you move here (pointing somewhere), <br>and Ship B, you fire at this location (pointing somewhere else)".<br><br>It's really important that the "pointing" actions in the graphics are <br>well-synchronized with the speech giving the commands......<br><br>So, the real-time UDP speech needs to be time-synched with the graphics <br>images over TCP.<br><br>So, here's some money....make it work....and .... mechanisms such as NTP <br>(thank you Dave Mills!) are created to provide high-accuracy global <br>time. But I have no idea if the voice/graphics synching is guaranteed <br>even today. Sure hope so...<br><br>There were a number of these scenarios that drove our thinking about the <br>problems. I was an initial member of Vint's IAB (then called ICCB), and <br>these kinds of scenarios played a significant role in those discussions, <br>which complemented the technical discussions in the larger Internet <br>group meetings. The IAB in part acted as a conduit to translate the <br>desires of the guys with the money into the technical goals that drove <br>the creation of the TCP/IP protocols and machinery.<br><br>Someone (I wish I knew who) made the decision to do all of this work, <br>and spend all of that money, in an open environment, and make the <br>technology freely available and standardized for anyone to use. None of <br>the competing Internet architectures (Xerox, Novell, DEC, IBM, ISO, <br>etc.) did that. So when the rest of the world discovered that the <br>military TCP/IP technology not only worked but also could solve their <br>problems, the ascension of the Internet was natural.<br><br>So, that's why we have TCP!<br><br>As usual, I've written a lot, sorry about that. It just seems important <br>to get this written down somewhere to capture some of the "why" part of <br>the Internet history. The existence of concrete scenarios was key in <br>focusing the technical work on actual real-world problems to be solved. <br>That permeated the culture of the Internet developers. Instead of <br>writing documents, we wrote code...<br><br>/Jack Haverty<br>August 31, 2016<br><br><br><br><br>On 08/31/2016 07:17 AM, Dave Crocker wrote:<br>> On 8/31/2016 6:50 AM, Craig Partridge wrote:<br>>> As I recall the story (I arrived on the scene later), Bob Kahn was in<br>>> the process of funding Packet Radio Networks and he and Vint needed to<br>>> solve the<br>>> interconnection problem and that motivated the TCP paper.<br>><br>><br>> This is a variant of the broader problem statement I was used to hearing:<br>><br>> Even by 1972 there already were a variety of independent networks<br>> around the world. How to interconnect them, since it was unlikely that<br>> they would all agree to switch over to someone else's network protocols.<br>><br>> TCP was developed as an overlay that would run on all of them,<br>> connecting them.<br>><br>> d/<br>><br><br><br>------------------------------<br><br>Message: 2<br>Date: Wed, 31 Aug 2016 18:29:05 -0400<br>From: Vint Cerf <<a ymailto="mailto:vint@google.com" href="mailto:vint@google.com">vint@google.com</a>><br>Subject: Re: [ih] Why TCP?<br>To: Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>><br>Cc: internet history <<a ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a>><br>Message-ID:<br> <CAHxHggd8=NHr6T-j89ANp+<a ymailto="mailto:sDOYak8sVtV1YyQs3EDfZYc9rAxA@mail.gmail.com" href="mailto:sDOYak8sVtV1YyQs3EDfZYc9rAxA@mail.gmail.com">sDOYak8sVtV1YyQs3EDfZYc9rAxA@mail.gmail.com</a>><br>Content-Type: text/plain; charset="utf-8"<br><br>On Wed, Aug 31, 2016 at 5:43 PM, Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>> wrote:<br><br>><br>> We even mused about extreme networking. For example, TCP/IP should be<br>> able to utilize a "network" implemented using carrier pigeons for<br>> transport, with each pigeon carrying a small tube with a strip of paper<br>> containing one packet of data.<br>><br>> As far as I know, no one ever did that...<br><br><br>yeah, they did - there's even an RFC about it, I think, from UK.<br><br><br>see also YouTube: <a href="https://www.youtube.com/watch?v=XQCZH9Lp8uo" target="_blank">https://www.youtube.com/watch?v=XQCZH9Lp8uo</a><br><br>The audio and auto-caption is hilariously disconnected.<br><br><a href="https://entertainment.slashdot.org/story/09/08/29/1934251/pigeon-protocol-finds-a-practical-purpose" target="_blank">https://entertainment.slashdot.org/story/09/08/29/1934251/pigeon-protocol-finds-a-practical-purpose</a><br><br><a href="http://www.cnet.com/news/pigeon-powered-internet-takes-flight/" target="_blank">http://www.cnet.com/news/pigeon-powered-internet-takes-flight/</a><br><br>v<br><<a href="http://www.cnet.com/news/pigeon-powered-internet-takes-flight/" target="_blank">http://www.cnet.com/news/pigeon-powered-internet-takes-flight/</a>><br><br>-- <br>New postal address:<br>Google<br>1875 Explorer Street, 10th Floor<br>Reston, VA 20190<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <a href="http://mailman.postel.org/pipermail/internet-history/attachments/20160831/30aad3c0/attachment-0001.html" target="_blank">http://mailman.postel.org/pipermail/internet-history/attachments/20160831/30aad3c0/attachment-0001.html</a><br><br>------------------------------<br><br>Message: 3<br>Date: Thu, 1 Sep 2016 10:31:16 +1200<br>From: Brian E Carpenter <<a ymailto="mailto:brian.e.carpenter@gmail.com" href="mailto:brian.e.carpenter@gmail.com">brian.e.carpenter@gmail.com</a>><br>Subject: Re: [ih] Why TCP?<br>To: Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>><br>Cc: <a ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a><br>Message-ID: <<a ymailto="mailto:50804405-fff3-c6cb-421a-44d1bf08ab2c@gmail.com" href="mailto:50804405-fff3-c6cb-421a-44d1bf08ab2c@gmail.com">50804405-fff3-c6cb-421a-44d1bf08ab2c@gmail.com</a>><br>Content-Type: text/plain; charset=utf-8<br><br>On 01/09/2016 09:43, Jack Haverty wrote:<br>...<br>> For example, TCP/IP should be <br>> able to utilize a "network" implemented using carrier pigeons for <br>> transport, with each pigeon carrying a small tube with a strip of paper <br>> containing one packet of data.<br>> <br>> As far as I know, no one ever did that....<br><br>Of coure they did:<br><a href="http://www.blug.linux.no/rfc1149/writeup/" target="_blank">http://www.blug.linux.no/rfc1149/writeup/</a><br><br> Brian<br><br><br><br>------------------------------<br><br>Message: 4<br>Date: Wed, 31 Aug 2016 18:35:06 -0400<br>From: Vint Cerf <<a ymailto="mailto:vint@google.com" href="mailto:vint@google.com">vint@google.com</a>><br>Subject: Re: [ih] Why TCP?<br>To: Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>><br>Cc: internet history <<a ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a>><br>Message-ID:<br> <CAHxHggfi9-LNbV71bUSX6ozkX=<a ymailto="mailto:GTtioTLdVTMk2EhBi_Y-Z3wg@mail.gmail.com" href="mailto:GTtioTLdVTMk2EhBi_Y-Z3wg@mail.gmail.com">GTtioTLdVTMk2EhBi_Y-Z3wg@mail.gmail.com</a>><br>Content-Type: text/plain; charset="utf-8"<br><br>On Wed, Aug 31, 2016 at 5:43 PM, Jack Haverty <<a ymailto="mailto:jack@3kitty.org" href="mailto:jack@3kitty.org">jack@3kitty.org</a>> wrote:<br><br>><br>> Someone (I wish I knew who) made the decision to do all of this work,<br>> and spend all of that money, in an open environment, and make the<br>> technology freely available and standardized for anyone to use. None of<br>> the competing Internet architectures (Xerox, Novell, DEC, IBM, ISO,<br>> etc.) did that. So when the rest of the world discovered that the<br>> military TCP/IP technology not only worked but also could solve their<br>> problems, the ascension of the Internet was natural.<br><br><br>Bob Kahn, Larry Roberts and Dave Russell are probably the closest to the<br>deciding parties<br>at the IPTO level but one has to credit George Heilmeier and Steve Lukasic<br>as DARPA<br>Directors for their strong support for ARPANET and then Internet.<br><br>v<br><br><br><br>-- <br>New postal address:<br>Google<br>1875 Explorer Street, 10th Floor<br>Reston, VA 20190<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <a href="http://mailman.postel.org/pipermail/internet-history/attachments/20160831/86df189e/attachment.html" target="_blank">http://mailman.postel.org/pipermail/internet-history/attachments/20160831/86df189e/attachment.html</a><br><br>------------------------------<br><br>_______________________________________________<br>internet-history mailing list<br><a ymailto="mailto:internet-history@postel.org" href="mailto:internet-history@postel.org">internet-history@postel.org</a><br><a href="http://mailman.postel.org/mailman/listinfo/internet-history" target="_blank">http://mailman.postel.org/mailman/listinfo/internet-history</a><br>Contact <a ymailto="mailto:list-owner@postel.org" href="mailto:list-owner@postel.org">list-owner@postel.org</a> for assistance.<br><br><br>End of internet-history Digest, Vol 105, Issue 37<br>*************************************************<br><br><br></div> </div> </div> </div></div></body></html>