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Vint Cerf on Internet Challenges
chamilto0516 writes "Phil Windley, a nationally recognized expert in using information technology, drove up to the Univ. of Utah recently hear this years Organick Lecture by Vint Cerf, one of the inventors of the Internet. In his notes, Vint talks about, 'Where is the Science in CS?' He also goes on to talk about real potential trouble spots with the Internet, but there is a bit on Interplanetary Internet (IPN). Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes."
Well... Duh!
I just assumed everyone ~knew~ we'd be using UDP between planets...
Sheesh... do I have to send a memo about ~everything???
Agile Artisans
What an incredibly poorly written article. There was good content but it was like jogging through a field of boulders......
http://www.busyweather.com/
TCP assumes anything over 2 minutes is a lost packet.
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It's a person? I thought it was a number at first.
Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes.
That's what subspace communication is for. I would hope that a geek of his caliber has at least watched some Star Trek.
To quote a site that bothers to keep the quote around for Google's sake:And he did take initiative in creating the Internet. In fact, he pushed funding for it through a congress that was convinced that anything attached to the military (and keep in mind that NSF and DARPA *are* connected to the military) was "the enemy". I heard Gore speak back then, and he was passionate about the creation of a national research network and how important it was.
The Internet is here with us today as much because of the funding as because of the science, and Gore was the money man.
Persoanlly, I find some of his politics a bit extreme, but like or hate liberal politics, you have to admit that the media dropped the ball by not calling Bush on this.
Vent Cerf = 1
AC = 0
I heard Vint Cerf speak at an e-business conference (remember when those were popular?).
He talked extensively about how the layered architecture of the internet poses a serious challenge to business models. The fact that any application can communicate through any physical medium (of sufficient bandwidth) was great for interoperability, but hard on businesses that provide the physical layer.
The problem is that all of the value is in the application layer -- people want to run software, download movies, chat with friends, etc. Whether the data flows on copper, fiber, or RF is irrelevant to the end-user and the layered architecture ensures that this is irrelevant. In contrast, a lot of the cost is in that "irrelevant" physical layer -- the last mile is still very expensive (we can hope WiMax reduces this problem). This gulf between cost and value forces physical infrastructure providers into a position of being a commodity providers with severe cost competition. If the end-user doesn't care how their data is carried, then they tend to treat bandwidth as a commodity.
I think he was wearing his MCI hat at the time of this talk and was influenced by the beginnings of the dot-com crash. MCI's subsequent bankruptcy was not surprising. Understanding this issue explains why telecom companies don't want municipal wifi and insist that you only network your cellphone through their networks. The only way to make infrastructure pay is to bind the high-value software application layer to the high-cost hardware layer. But this strategy violates the entire layered model and enrages consumers.
Two wrongs don't make a right, but three lefts do.
Well, and maybe having his own website up there at phil.whendley.com.
Seems kind of far from a Nationally recognized expert to me. I'd never heard of him - why do I associate his name with a talk that Vint Cerf gave and apparently this guy gave no value too, other than driving there and listening
I have mod points and I am not afraid to use them
Even if CS came up with a scientific solution to improve code quality, it would be an interesting exercise to see if the industry will be willing to absorb the costs associated with such a solution. Especially in an environment where end customers are well-trained to accept and deal with software quality issues.
40 minutes = 2400 seconds
Speed of light = 299,792.458 kilometers per second
Distance from Earth to Mars: 55,700,000 kilometers (minimum) 401,300,000 km (maximum)
Time of travel at speed of light to mars: 401,300,000/299,792.458 = ~1339 second
Since Mars is supposedly the first place we're likely to go farther away than the moon it seems that we are fine for now.
Right? Or is there not a way to send data in form of light, or do radio waves travel slower than light?
Anyway, someone correct me here
"Oh, you hate your job? There's a support group for that, it's called everyone, they meet at the bar."
Over a 100Mb LAN the difference is effectively nothing, but once you involve slow and lossy networks the difference is considerable. The impact is great enough over terrestrial radio nets and is a zillion times worse interplanetary.
Let's say you have a rover that sends a position message once a second. What you're really interested in, typically, is the most up to date info. If you're using tcp, then you won't get the up to date info until the retries etc have been done to get the old info through (iie. it's noon, but the noon data is not being sent because we're still doing the resneds to get the 8 am data through). This means that the up to date info gets delayed. With udp the lost data is just ignored and the up to date data arrives when it should.
Of course ftp still (might) be a useful way to shift large files etc, but often the udp equivalents (eg. tftp instead of ftp) will be more apropriate.
Engineering is the art of compromise.
I thought, years ago when I was looking at it, that IPv6 had a TTL that was modifiable, and thus wouldn't time out.
....
But, as a practical matter, it would work better as an FTP request does, where you stream the data in blocks and resend any missed blocks later. This would work fairly well for lossy protocols like JPEG or suchlike, but a good image format should be able to handle it, but time stop/start protocols might get glitched and would have to be replaced.
Anyone for MP7? TUFF instead of TIFF?
The other question is, would this be on the same network, or would, given the very small number of network nodes concerned, it be on a network that we bridge to and translate as needed, buffering the data streams on each end.
Now, if you had a martian sandstorm for a few days, that's probably not going to be that helpful, but you get the idea
-- Tigger warning: This post may contain tiggers! --
That sounds like a hardware problem to me. Therefore, most computer scientists will ignore it.
Have you read my blog lately?
Vint Cerf is one of two men who designed the TCP/IP protocol that we use today. See http://en.wikipedia.org/wiki/Vint_Cerf/
Wow. If I had known that he was such a celebrity, I probably would have paid more attention in his Enterprise Systems class at BYU.
I guess it's nice to learn from someone important who doesn't act like the world revolves around him.
"With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea...."
RFC 1925
Note the key phrase "one of" in the story.
I actually attended this lecture yesterday and Vinton disclaimed the "father of the internet" moniker, saying that he co-designed the original TCP/IP protocol but that he and Bob Kahn and that that work was largely based on the ARPANET design which was in turn based on packet radio, etc. So yes, the man himself said he was just one of a long list contributors.
He did joke though that his son once asked if he was the "brother of the Internet".
He also commented that one of the properties of the system that he was quite happy with was the ease with which others could contribute at any level of the system, including building new application layer protocols on top of the basic protocols without going and needing to go and get permission from someone. People can just go out and write new protocols and build the apps to use them. (e.g. Bit Torrent) He said he thought that the Internet is largely where it is today because of that openness to the contributions of thousands of people.
Bonus points for telling us where he pinched the idea from?
Latency is measured in units of time. Lightyears are a measure of distance.
TCP's no good using standard broadcast methods
Huh? If I knew what you meant to say, it'd be easier to show you were wrong...
We need something that'll be as fast as fiber, but will stretch way way longer in distance.
So, like, line-of-sight laser communication?
Current radio's a broadcast. Can't do that, especially with package leakage.
How do you think we're communicating with the Mars rovers now? Or other planetary explorers?
I belive there was some experiments in quantum transmissio of data, in which an electron was split and one half sent to Munich, the other sent to Venice, and transmissions where near-instantaneous.
You can instantaneously determine what the other side received, but no information can be transmitted this way.
I see you have a low user-id, and therefore have learned to get modded up for saying stuff that is nonsensical and wrong. I must admit I'm impressed. I earn all my mod points the hard way.
I think people generally don't understand what computer science is. CS isn't a 4 year degree to learn how to program or set up a network. It's about having the theoretical background to be able to analyze and evaluate comptuter technologies. Classes like automata theory and theoretical data structure classes are necessary to be able to both 1) apply a real solution to a problem and 2) be able to argue the validity of that solution. There is a lot of science in CS.
You can't transfer information over entangled particles. Furthermore, faster than light information transfer violates relativity.
Realtime communication with a Martian node is physically impossible. It's simply too far away.
Realistically, we might see a proxy architecture as follows:
1) All traffic is "queued" at an earth-bound substation. Communication is TCP-reliable to this node; transport layer acknowledgements are degraded to "message received by retransmitter" (end-to-gateway) rather than "message received by Mars"(end-to-end). Since both Earth and Mars are in constant rotation, a "change gateway" message would need to exist to route interplanetary traffic to a different satellite node (think "global handoff").
2) Transmission rates from Earth to Mars are constant, no matter the amount of data to send. Extra link capacity is consumed by large-block forward error correction mechanisms. Conceivably, observed or predicted BER's could drive minimum FEC levels (i.e. the more traffic being dropped, due to the relative positions of the Earth and Mars, the less traffic you'd be willing to send in lieu of additional error correction data.
3) Applications would need to be rewritten towards a queue mentality, i.e. the interplanetary link is conceivably the ultimate "long fat pipe". Aggressively publishing content across the interplanetary gap would become much more popular. As much content has gone dynamic, one imagines it becoming possible to publish small virtual machines that emulate basic server side behavior within the various proxies.
You'd think all this was useless research, as there's no reason to go to Mars -- but TCP doesn't just fail when asked to go to Mars; it's actually remarkably poor at handling the multi-second lag inherent in Geosat bounces. Alot of the stuff above is just an extension of what we've been forced to do to deal with such contingencies.
--Dan
Absolutely not. Gore entered Congress in 1977, well after any point that could reasonably be construed as the "creation" of the ARPAnet/Internet. It's true that he never claimed to have "invented the Internet" but what he did say is still completely untrue.
What I'm listening to now on Pandora...
For me, its not science if it doesn't involve the methods of empiricism. Observation, hypothesis, repeat.
The only time this really happens with computers is troubleshooting.
Programmers may think in a logical or analytical way, but thats not science. And its a good thing to. If programmers weren't allowed to make stuff up as they went along but instead had to use scientific method for everything they did not many progams would be completed.
We know almost nothing about making programming more efficient and systems more secure and scalable. He characterizes our progress in programming efficiency as a "joke" compared to hardware.
It's definitely a joke - and the real joke is that it can't even be characterized as "progress". The programming of today is worse than it was a couple decades ago and consistently declines. I have talented friends who have dropped out of the industry in disgust over what passes as programming nowadays.
Maybe Vint Cert should be talking about the evils of "computer science" being taught around Java, or the fact that many CS programs have become little more than glorified job training.
According to Cerf, "The first demonstration of the triple network Internet took place in July 1977". He refers to this event as the "Birth of the Internet". Prior to that, researchers could send messages but had to be very familiar with the underlying technology.
In a September 2000 email, Cerf and Kahn give Al Gore much credit in the development of the Internet: http://www.mintruth.com/wiki/index.php?Al%20Gore%
Two excerpts:
Well... He was working at the patent office and there was this....
.....
...
Oh, wait, that was a German Physicist....
Video Production Support
Once you're talking about wormholes big enough to send a stream of photons through, there are many other implications. Arthur C. Clarke and Stephen Baxter's The Light of Other Days is an interesting thought experiment in that direction.
... it breaks some interesting ground and is very thought provoking.
Basically they suggest that it opens up the possibility of wormhole cameras which can be used to view what's happening anywhere at any time without anyone's knowledge. Privacy is completely destroyed and civilization, um, takes a while to get over that fact. Later in the book other corollary results show up which are even more far out.
It's not a great book in terms of its plot, but it's classic SF
You are talking about trying to measure theoretical information content, bits of entropy. In the proper context that is a perfectly valid concept of 'bit'. however the common definition and usage of bit is anything that can be in two states, and those states need not be equally likely.
My computer has a about a billion of bits of RAM, even if on average 90% of them are zero.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
That's strange. I thought that issue would have been worked out by RFC 1149 or CPIP. You would think that 40 minute transit times would be a quick ping when using the Carrier Pigeon Internet Protocol (CPIP).
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