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NASA DTN Protocol: How Interplanetary Internet Works
First time accepted submitter GinaSmith888 writes "This is a deep dive in the BP protocol Vint Cerf developed that is the heart of NASA's Delay-Tolerant Networking, better known as DTN. From the article: 'The big difference between BP and IP is that, while IP assumes a more or less smooth pathway for packets going from start to end point, BP allows for disconnections, glitches and other problems you see commonly in deep space, Younes said. Basically, a BP network — the one that will the Interplanetary Internet possible — moves data packets in bursts from node to node, so that it can check when the next node is available or up.'"
The main problem is the long delay at light speed.
TLDR X.25 with big buffers
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
:( :( :(
I thought something like this already existed. And it worked pretty well at the time.
http://en.wikipedia.org/wiki/UUCP
The only problem with the BP protocol is the data mining rigs that burst and spread raw SQL queries all over the coast of Amazon.com and then wonder why people are pissed that they can't buy or sell from that site until its cleaned up!
...with the tech lower in the piece"
Except, they never do.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
This is where you're completely wrong. Having a network infrastructure that extends outside of our planet (an extranet if I ever heard one!) is a requirement for being able to do things like set up bases and control robotic devices remotely. What we're doing is setting the groundwork for more than one user or group to both control and receive the telemetry from whatever mechanized device we send outside of our own atmosphere! This is huge!
Consider this: We send a basic construction rover and a 3D printer to Mars. Both are controlled by DTN/BP. We can send the 3D printer blueprints for parts and assembly instructions to the construction rover. That would allow us to build up an infrastructure before we even get there and monitor it by adding parts on an as-needed basis. It would allow us to do so cheaper as well, as things can be sent in smaller chunks, and some of it could be manufactured on the fly on site. Doing this using any of the older protocols or even proprietary mechanisms could make things much more complicated, especially if you decide to handover control or add members to a project you've already started.
Reminds me of the problems the old FidoNet had to deal with - nodes not being available, or only available for short times, poor quality connections, low speed, etc. It worked remarkably well for all of those conditions I thought :)
Don't judge me based on my high slashdot user id!
While on the subject, when are we going to establish repeater stations around the solar system so that space probes don't need massive transceivers and line-of-sight to communicate with the Earth?
Isn't IP already delay tolerant? I remember in the IPoAC trial for obvious reasons there were huge delays, but it still worked.
Well, the protocol could also be useful on earth, for example when there is a huge catastrophe. Besides, basically the whole Internet has been developed by government agencies at the expense of tax payer money. If the Internet had been developed by private industry, we'd all have $49.95/month AOL network access over modem that would provide about 8 network-capable applications with pay-per- use extra services.
Actually it sounds more like fidonet. Store and forward networking just like early infrastructure that let email from dial up bbs nodes eventually reach a destination.
You mean the same way private industry invented the current internet protocols? Hint - they didn't. I think the point is while we don't have people out beyond the moon we do have an ever-increasing number of *machines* out there, every one of them equipped with a custom communication mechanism rendering them incapable of communicating with each other. If we work out a nice robust, standardized protocol now then not only do future probe developers (also mostly government funded) not need to spend time and money developing a new communication protocol, but future probes have the potential to intercommunicate with each other as well. One obvious application would be using "healthy" probes to act as relay stations for probes whose antennas or power supplies have degraded to the point that they no longer have the necessary gain to reliably communicate with Earth, but are otherwise operational. Or to route signals along clean signal paths where much lower transmission power is necessary - for example if a probe is in conjunction with Jupiter, the sun, or some other powerful radio source it is presumably much more difficult for Earth to receive a clean signal directly from it (or contrariwise if it was Earth in conjunction from the probe's perspective) Beyond that, who knows? Certainly few people envisioned most of the current uses of the internet when the protocols were being developed.
Oh, and we have plenty of mechanisms to get people past the moon, just getting into high orbit puts us half way to anywhere in the solar system, and it's actually easier to reach Earth's L3- and L4-point asteroid fields than it is to reach the Moon, we just haven't really had the motivation to do so yet. We could even get to Mars pretty easily with current technology if we wanted to, though arranging a return trip complicates things a little since we'd be down at the bottom of a gravity well again - i.e we'd need to either carry a staggering amount of extra fuel along, or establish a refueling base there. There'd be no shortage of volunteers for a one-way trip though, *especially* if the plan was to set up a sustainable base which would eventually (after years/decades) enable round trips to begin.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
And now the question is: when will Linux support it?
I am not really here right now.
The problem is most any terrestrial network protocol expects a minimal signal-response delay between nodes, whereas even a perfectly functioning terabit/s Earth-Mars link would still have between a 6 and 40 minute delay due to the speed of light.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Better figure out how to access "subspace" if you want to play Halo 27 with your friends on Titan. Or maybe quantum entanglement could accomplish the same thing?
If you could reason with religious people, there would be no religious people
ION is probably the most popular open source implementation of DTN, and was developed on Linux machines..
Have gnu, will travel.
I've no doubt they'll succeed with this, but if they are going to do remote robot control they are going to have to develop a very 'interesting' command structure. I can see it now... Go Forward... Stop... Oops!
Sending a 3D printer to Mars? Are you out of your mind?
Better anticipate on the things you want to do on Mars, than to send over raw materials and a 3D printer, and think... "gosh, what shall we put together today?"
My karma ran over your dogma
It sounds like a UUCP implemented at layer3.
I want to delete my account but Slashdot doesn't allow it.
Gaming must really suck, how are astronauts going to play online!? Well at least they can Download their Steam library..
I fucking hate that saying.
Sarah Palin is our revenge for you assholes acting like we don't exist.
Does anyone have more information about the Lego Mindstorms robot that was used in this experiment? I'd like to use it as an inspiration with the kids.
The Curiosity Rover Made With Lego Mindstorms is pretty cool, but the fact that it uses "7 NXT Bricks, 13 NXT Motors, 2 Power Function Motors" makes it out of reach of the average home.
Better anticipate on the things you want to do on Mars, than to send over raw materials and a 3D printer, and think... "gosh, what shall we put together today?"
It's more like "gosh, what broke today?"
Assuming a 3D printer could work on Mars (no idea if that's possible), you could use it to greatly increase efficiency. Instead of sending over 2 or 3 of every possible item that might break or wear out, you could just send over 2 or 3 3D printers, and use them to replace broken tools as necessary. (Including, of course, worn-out 3D printers ;^))
I don't care if it's 90,000 hectares. That lake was not my doing.
DTN is a store-n-forward protocol.
Conceptually kinda sorta like email in that regard.
The BP side of the equation brings the concept of bundling more information together in one unit (unlike IP, which tends to break info into smaller units , eg fragmentation).
The plan being to bundle together all the information required for The Application to do the next thing.
Imagine sending all the html-and-javascripts-and-css for a webpage in one (huge) packet. Your browser would have enough to render the page and start requesting the images (etc). If you were using a text-only browser, you'd have everything you needed - just waiting for the next user-input.
Visit CryptoGnome in his home.
This is something for private industry to figure out. Why are our tax dollars being wasted on stuff like this when in reality, we have no mechanism to get men past the Moon for the next 20-30 years? Shouldn't we spend tax dollars on stuff that is useful, such as not being beholden to our #1 creditor, China?
We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.
Its saturnine enough here?
This is something for private industry to figure out.
Private industry R&D looks 5-10 years down the road. A great nation will look 20, 50, and even 100 years down the road.
Why are our tax dollars being wasted on stuff like this
Wasting? This stuff is peanuts for the federal budget, and it probably even saves money (e.g, allowing different missions to use a common communication infrastructure).
we have no mechanism to get men past the Moon for the next 20-30 years
We put man on the moon with less than a decade's worth of work using 60's technology. If we were motivated, we could put men on mars within a decade too.
All of which is beside the point... we're sticking unmanned infrastructure out there (in various orbits, at Lagrange points, on the Martian surface, etc.) and the amount of data we want to ship around is getting progressively larger and larger.
such as not being beholden to our #1 creditor, China
We can always print more dollars. The real worry with China, it seems to me, is that we gave them our manufacturing capacity and business know-how. Now their economic ascendency is putting a strain on world resources (e.g., see gas prices) and we have to fret over whether or not their hardware is spying on us. Credit isn't a big worry since we control our own currency (unlike Greece, for instance).
We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.
To fix it, you're going to have to find the political will to cut defense, cut entitlements, and raise taxes. Good luck.
-1, Too Many Layers Of Abstraction
This sounds just like FIDO used for inter-BBS and early internet email. Nodes would queue messages until the next hop was available. Why isn't the plan to use pairs on intangled particles to instantly pass information without regard for the speed of light or distance between end-points?
...something amateur ("ham") radio operators have been using since the 1980's...
-allen
KC2KLC
I am not a number - I am a free man!
Shouldn't we spend tax dollars on stuff that is useful, such as not being beholden to our #1 creditor, China?
My, don't we sound talking-pointy.
http://finance.yahoo.com/news/biggest-holders-of-us-gov-t-debt.html
That’s right, the biggest single holder of U.S. government debt is inside the United States and includes the Federal Reserve system and other intragovernmental holdings.
What I've seen the Ayn Rand types want everything to be a meritocracy. The average engineer really only invents things on the scale of "years". The number of "landed & monied" inventors like Thomas Jefferson is considerably less than 1%. The average engineer has to have a "day job"... That means you invent what the boss is paying you for. For every engineer threatening to "go Galt" there ten more hungry, eager kids out of school that will do what the boss ASKS. It's is also the reason we don't have tech unions... We know we're glorified "boys with toys" and far more replaceable than we like to admit.
Back on topic, in the 1960's AT&T had the best engineers in the world... Working to make your phone bill "do more things". UNIX was entirely built to make sure AT&T could recoup charges from businesses that wanted to use its new computers. This is the same AT&T that demo'd video phones and watch phones In the 1960s... Still banning those features from phones right now. BECAUSE THEY CAN'T FIGURE OUT HOW TO PROFIT.
Fortunately there was still enough "blue sky" research going on at the tech titans that when baby-ARPA came looking for sci-fi projects the suits were happy to collect the Federal money but not quite clever enough to understand just what the research going on was about to pull off. In fact, it still took 20 more years for the full effect to be realized...
Forget all this talk of UUCP, Fido and normal packet protocols, the closest current similarity is sending binaries over usenet.
The most important part is the delay time, when you 'launch' a usenet message you won't receive anything at all from the remote end for a very long time. It will probably be long enough for you to transmit the entire message and then some.
The medium also has some limitations ...
For usenet the binary files are packaged up into one archive them split into messages. Usually something isn't considered to be received until the entire archive has been received intact. It used to be that the receiving end would request repeats of messages that didn't get through. This takes a long time and wasn't simple to automate because of the multiple receiver nature of usenet. Nowadays more messages are added using the 'parchive' protocol the idea being that the extra messages are 'universal substitutes'. Say the transmitter needs to send out an archive of 1000 messages, furthermore it's likely that 4%-9% of messages will be lost, then adding 100 extra PAR messages will (normally) mean that the archive will get there intact first try. No retransmission request needed.
I expect 'bp' is very similar.
Hmm, you must have been on a different Internet than I was. Do we remember when .com sites were considered poison and site admins refused to route traffic for them? Because they were profit-driven and diametrically opposed to the government-run version of the Internet? I do.
You could fill a book with communications protocols which never took off due to not being widely adopted. Indeed, many books of this type exist. You could even fill a book with communications protocols whose creators were vehemently opposed to their being used by profit-making entities - which probably explains why they never went anywhere.
Shutting down free speech with violence isn't fighting fascism. It IS fascism!
The UUCP analogy is wrong anyway. The point is that even in UUCP days, we connected two modems, which transmitted data with X, Y or Z protocol. And that protocol was even more sensitive to propagation delays, because acks had to be sent much more frequently. Try set up UUCP to a mars probe, and you'll see that the layer 2 protocols will probably break down pretty badly. That's why DTN is really important and an entirely different kind of beast.
cpghost at Cordula's Web.
You are not thinking creative enough. You can have a 3D printer which of course can print spare parts for itself and have say a robot who can gather materials etc. Of course, the printer can print another 3D printer and another robots so we can infest the Mars in no time.
The only problem is that the printer which can print its own parts must be complicated and of course converting raw materials to printable ink is nigh impossible.
But in any case, imagine the possibilites! It isn't logically impossible, there are technical difficulties but not impossible barriers.
Trolls are like broken clocks. They show the truth two times a day. The rest of the day they talk nonsense.
"Basically, a BP network — the one that will the Interplanetary Internet possible — moves data packets in bursts from node to node, so that it can check when the next node is available or up."
Err... didn't this used to be called FidoNet?
Hire a Linux system administrator, systems engineer,
Legitimate Bufferbloat?
Remember modem connections and 'feeds' for news and email? When most links were offline most of the time? Yep, networking before 'up all the time' connections were available to most of the world.
I had a Linux (and before that a Mark Williams 'Coherent' UNIX like) computer that ran UUCP, and did dial on-demand connections. I had it download email and subscribed usenet 'news feeds' nightly from a local university that had 'free' connections for members of the local UNIX computer users group.
It worked. It was solid once I got all the config's right.
Not long ago I saw some articles on the wide area network wireless internet in Africa uses these techniques even today to get connectivity 'out there' without having to have 'up all the time' servers in remote communities.
Usenet newsgroup and email server software are still there and available if anyone wants to use them. Actually, I should look into that for my local use too!
I would like to see the new BP protocol implemented and distributed with Linux. It could be great for implementing 'automotive node' networks (put a BP node in your car, and it could communicate whenever it found a un-secured WIFI connection as you drive down the road!
Dreaming... Life goes on.
... "When you pry the source from my cold dead hands."
I'll admit my early 'net history is rather shakey, but by that point hadn't the academics pretty much taken it over? It wasn't government-run much beyond the early proof-of-concept phase, and I don't recall commercial entities getting terribly involved until much later, some time after the Web was developed and started becoming popular. And sure, I know plenty of academics to this day that have no love for the commercial side of the internet. Nevertheless the commercial side eventually managed to flourish and once the ideological battle died down it was able to seamlessly integrate into the wider internet precisely because the protocols were openly available for anyone to implement. Had they had to develop their own protocols and infrastructure then (A) it's much less likely the commercial side would have ever gotten off the ground, and (B) if it *did* get off the ground we would now have two separate, incompatible internets and the world would be a poorer place for it.
--- Most topics have many sides worth arguing, allow me to take one opposite you.