A carrier pigeon laden with microSD cards can transfer large amounts of data faster and cheaper than almost any other method.
Note. transl.: although the original of this article appeared on the IEEE Spectrum website on April 1, all the facts listed in it are quite reliable.
In February about the release of the world's first microSD flash card with a capacity of 1 terabyte. It, like other cards of this format, is tiny, measuring only 15 x 11 x 1 mm, and weighs 250 mg. It can fit an incredible amount of data into a very small physical space, and you can buy it for $550. For your understanding, the first 512 GB microSD cards appeared just a year earlier, in February 2018.
We've become so accustomed to the speed of advances in computing that these increases in storage density go largely unnoticed, and sometimes get a press release and a couple of blog articles. More interesting (and likely to lead to more serious consequences) is how much faster our ability to generate and store data is growing compared to our ability to transmit it over networks accessible to most people.
This problem is not new, and for several decades various types of "smartnets" have been used to physically transport data from one place to another - on foot, by mail, or by more exotic means. One method of data transmission that has been actively used for the last thousand years is carrier pigeons, which are able to travel hundreds or even thousands of kilometers long, returning home, using navigational techniques, the nature of which has not yet been accurately studied. It turns out that in terms of throughput (the amount of data transferred over a given distance in a given time), a pigeon-based perinet remains more efficient than typical networks.
From the "IP Datagram Standard for Air Carriers"
On April 1, 1990, David Weitzman proposed Request for Comment (RFC) titled "", now known as IPoAC. RFC 1149 describes an "experimental method for encapsulating IP datagrams in air carriers", and has already had several updates regarding both QoS and transition to IPv6 (published April 1, 1999 and April 1, 2011, respectively).
Sending RFCs on April Fool's Day is a tradition that began in 1978 with RFC 748, which proposed that after sending an IAC DONT RANDOMLY-LOSE command to a telnet server, the server would stop randomly losing data. Pretty sound idea, right? And this is one of the properties of the April Fool's RFC, explains who chaired the Networks Working Group at CERN from 1985 to 1996, chaired the IETF from 2005 to 2007, and now lives in New Zealand. “It has to be technically feasible (i.e., not violate the laws of physics), and you have to read at least a page before you realize it's a joke,” he says. “And, of course, it must be absurd.”
Carpenter, along with his colleague Bob Hynden, wrote the April Fools' RFCs themselves, where they described , in 2011. And even two decades after its introduction, IPoAC is still well known. “Everyone knows about air carriers,” Carpenter told us. “Bob and I were once talking at an IETF meeting about IPv6 adoption, and the idea of adding it to IPoAC came naturally.”
, which originally defined IPoAC, describes the many benefits of the new standard:
Many different services can be provided with peck prioritization. Additionally, there is a built-in recognition and destruction of worms. Since IP does not guarantee 100% delivery of packets, the loss of a carrier can be reconciled. Over time, carriers recover on their own. Broadcast is not defined, and storms can cause data loss. It is possible to make persistent delivery attempts before the carrier drops. Audit trails are generated automatically and can often be found in cable trays and on logs [English log means both "log" and "log for records" / approx. transl.].
The Quality Improvement Update (RFC 2549) adds a few important details:
Multicasting, although supported, requires the implementation of a device for cloning. Carriers can be lost if they are located on a tree that is being cut down. Carriers are distributed along the inheritance tree. Carriers have an average TTL of 15 years, so their use in expanding ring searches is limited.
Ostriches can be seen as alternative carriers, with much greater capacity to transfer large amounts of information, but provide slower delivery and require bridges between different areas.
For additional discussion of quality of service, see .
from Carpenter, describing IPv6 for IPoAC, among other things, mentions the potential complexities associated with packet routing:
The passage of carriers through the territory of carriers similar to them, without establishing agreements on equal information exchange, can lead to a sharp change in route, packet looping and delivery out of order. The passage of carriers through the territory of predators can lead to significant packet loss. It is recommended that these factors be considered in the routing table algorithm. Those who will implement these routes should consider policy-based routing that bypasses areas dominated by local and predatory carriers to ensure reliable delivery.
There is evidence that some carriers have a tendency to eat other carriers and carry the eaten payload. Perhaps this will serve as a new method for tunneling IPv4 packets within IPv6 packets, or vice versa.
The IPoAC standard was proposed in 1990, but homing pigeon messages took much longer to send: the photo shows a homing pigeon being sent in Switzerland, between 1914 and 1918
It is logical to expect from a standard, the concept of which was invented back in 1990, that the original format for transmitting data using the IPoAC protocol was associated with printing hexadecimal characters on paper. A lot has changed since then, and the amount of data that fits into a given physical volume and weight has increased incredibly, while the payload size of an individual pigeon has remained the same. Pigeons are capable of carrying a payload that is a significant percentage of their body weight - the average carrier pigeon weighs about 500 grams, and at the beginning of the 75th century they could carry XNUMX-gram cameras for reconnaissance in enemy territory.
We talked with , a Maryland pigeon racer, and he confirmed that pigeons can easily carry up to 75 grams (and possibly a little more) on themselves "throughout the day for any distance." At the same time, they can fly a considerable distance - the world record for a carrier pigeon is held by one fearless bird that managed to fly from Arras in France to its home in Ho Chi Minh City in Vietnam, having traveled 11 km in 500 days. Most carrier pigeons are, of course, not capable of flying that far. The typical length of a long race track, according to Lesofsky, is about 24 km, and the birds cover it at an average speed of about 1000 km/h. At shorter distances, sprinters can reach speeds of up to 70 km/h.
Putting all this together, we can calculate that if we load the carrier pigeon up to its maximum carrying capacity of 75 grams with 1 TB microSD cards, each of which weighs 250 mg, then the pigeon will be able to carry 300 TB of data. Having traveled from San Francisco to New York (4130 km) at the maximum sprint speed, he would reach a data transfer rate of 12 Tb / h, or 28 Gb / s, which is several orders of magnitude faster than most Internet connections. In the US, for example, the fastest average download speed is in Kansas City, where Google Fiber transfers data at 127 Mbps. At this speed, it would take 300 days to download 240 TB - and in that time, our pigeon would be able to circle the globe 25 times.
Let's say this example doesn't look very realistic because it's some kind of super pigeon, so let's slow down. Let's take a more average flight speed of 70 km / h, and load the bird with half the maximum load in terabyte memory cards - 37,5 grams. And still, even if we compare this method with a very fast gigabit connection, the dove wins. A pigeon will be able to circle more than half the globe in the time our file transfer is over, which means that it will be faster to send data by a pigeon to literally anywhere in the world than to use the Internet to transfer it.
Naturally, this is a pure throughput comparison. We do not take into account the time and effort to copy data to microSD cards, load them onto a pigeon, and read the data when the bird arrives at its destination. Latency is obviously high, so anything other than a one-way transfer would be impractical. The biggest limitation is that the carrier pigeon only flies in one direction and to one destination, so you won't be able to choose the purpose of sending the data, and you will also have to transport the pigeons to where you are going to send them from, which also limits their practical usefulness. .
However, the fact remains that even with realistic estimates of the payload and speed of the pigeon, as well as the Internet connection, the net throughput of the pigeon is not easy to beat.
With all this in mind, it's worth mentioning that pigeon data transmission has been tested in the real world, and they did a pretty good job of it. Bergen Linux user group from Norway in 2001 , sending one ping with each pigeon over a distance of 5 km:
The ping was sent at approximately 12:15. We opted for a 7,5 minute interval between packets, which should ideally result in a couple of packets being left unanswered. However, things didn't go quite like that. A flock of pigeons flew over our neighbor's property. And our pigeons didn't want to fly straight home, they first wanted to fly with other pigeons. And who can blame them for this, given that the sun came out for the first time after a couple of cloudy days?
However, their instincts won, and we saw how, after frolicking for about an hour, a couple of pigeons broke away from the flock and headed in the right direction. We rejoiced. And it was indeed our pigeons, for shortly afterwards we received a report from another point that a pigeon had landed on the roof.
Finally, the first dove arrived. The data packet was carefully removed from its paw, unpacked, and scanned. After manually checking the OCR and fixing a couple of bugs, the packet was accepted as valid, and our jubilation continued.
For really large amounts of data (such that the required number of pigeons becomes difficult to maintain), physical methods of movement still have to be used. Amazon offers a service – 45ft shipping container on truck. One Snowmobile can carry up to 100 Pb (100 Tb) of data. It will not move as fast as the equivalent flock of several hundred pigeons, but it will be easier to work with.
Most people seem to be satisfied with extremely slow downloads and have little interest in investing in their own carrier pigeons. It really takes a lot of work, says Drew Lesofsky, and the pigeons themselves usually behave, not like data packets:
GPS technology is increasingly helping pigeon racers and we are getting a better idea of how our pigeons fly and why some fly faster than others. The shortest line between two points is a straight line, but pigeons rarely fly in a straight line. They often zigzag as they fly in a roughly desired direction and then correct course as they approach their destination. Some of them are physically stronger and fly faster, but a pigeon that is better oriented, has no health problems and is physically fit can overtake a fast-flying pigeon with a bad compass.
Lesofsky has enough confidence in pigeons as carriers of data: “I would quite confidently send information with my pigeons,” he says, while taking care of error correction. “I would release at least three at once to ensure that even if one of them has a bad compass, the other two will have a better one, and in the end the speed of all three will be higher.”
Problems with implementing IPoAC and the increasing reliability of sufficiently fast (and often wireless) networks means that much of the services that relied on pigeons (and there were many) have switched to more traditional methods of data transmission over the past few decades.
And because of all the preliminary preparations required to set up a pigeon data transmission system, comparable alternatives (like fixed-wing drones) may become more viable. However, pigeons still have some advantages: they scale well, work for seeds, are more reliable, they have a very complex obstacle avoidance system built into them both at the software and hardware levels, and they can recharge themselves.
How will all this affect the future of the IPoAC standard? There is a standard, it is available to everyone, albeit a little absurd. We asked Brian Carpenter if he's working on future updates to the standard, and he said he's thinking about whether pigeons can carry qubits. But even if IPoAC is a little complicated (and a little silly) for your personal data transfer needs, all sorts of non-standard communications networks will remain necessary for the foreseeable future, and our ability to generate huge amounts of data continues to grow faster than our ability to transfer them.
Thanks to user AyrA_ch for pointing out the information to his , and for convenient , which helps to calculate how much pigeons really outperform other methods of data transmission.
Source: habr.com