Thursday, September 24, 2009


Carrier pigeon vs Internet Service Provider

Via BoingBoing, we hear about some wags who had a bandwidth race between DSL and a carrier pigeon. The pigeon won, but, as Cory points out, that’s not surprising, given the constraints of the test:

Now, this is very funny, but I think that over pigeon-traversable distances in which latency isn’t an issue, the pigeon will always win. A random web-page promises that a carrier pigeon can bear loads of up to 1.7 oz or about 48.2g. My postal scale says that my 64GB SD card weighs 2.05g. Which means that a pigeon could carry 23 64GB SD cards, or 1.472 terabytes. In the Telkom race, the pigeon traversed 40km in 2 hours.

I think that even the best commercial ISP in the world would be hard-pressed to deliver 736GB/h between two customer DSL end-points. Likewise, I think that even the greatest pigeon on the world would be hard-pressed to deliver even one bit of information from Cape Town to New York.

Of course, that wasn’t the point in the first place, but it’s always fun to analyze these things and run the numbers.[1] One thing it points out to us is how technology has changed, particularly with respect to data density. Who could imagine fitting about one and a half terabytes in about 2 ounces of weight... ten years ago?

Now, neither Cory nor the BBC article mentions the pioneering work that precedes this test by almost 20 years, the famous RFC 1149, from April first, 1990: A Standard for the Transmission of IP Datagrams on Avian Carriers. Befitting the technology of the time — memory sticks didn’t exist then — David Waitzman’s proposal has us put the data to paper:

The IP datagram is printed, on a small scroll of paper, in hexadecimal, with each octet separated by whitestuff and blackstuff. The scroll of paper is wrapped around one leg of the avian carrier. A band of duct tape is used to secure the datagram’s edges. The bandwidth is limited to the leg length. The MTU is variable, and paradoxically, generally increases with increased carrier age. A typical MTU is 256 milligrams. Some datagram padding may be needed.

Upon receipt, the duct tape is removed and the paper copy of the datagram is optically scanned into a electronically transmittable form.

David Waitzman updated this with Quality of Service information on April first, 1999 (RFC 2549), but, as Cory says: the latency is killer.

[1] Actually, while we’re analyzing: the BBC article first incorrectly says that “the pigeon took two hours to carry the data 60 miles,” and then later says that only about half that time was due to the pigeon: “The firm said Winston took one hour and eight minutes to fly between the offices, and the data took another hour to upload on to their system.” An hour to transfer 4 gigabytes from a memory stick? That sounds bizarrely long.

1 comment:

Richard T said...

This could be bonus time for the use of peregrine falcons, who have an appetite for pigeons, to disrupt communications.