Re: [PAPER] Juggling with packets: floating data storage

[Nicholas Weaver <nweaver@CS.berkeley.edu>]

On Wed, Oct 08, 2003 at 11:52:53AM -0500, Alun Jones composed:
> Of course, a real network engineer would remind you that you face two
> immediate problems regarding this technique:
> 
> 1. [UDP] Jugglers don't usually have to deal with oranges suddenly
> disappearing in midflight, or being duplicated.

This can be handled, up to a point, by standard error-handling
techniques.

However, a little bit of back-of-the-envelope on an orthoginal access:
Measuring the latency (how long the object remains "in the network").


There is a hypothetical Gb optical network link between here and the
moon, used for storage.

The moon is ~3e8 m from Earth (384,000 km).  Thus it is about 2
seconds of network latency from here to the moon.

Thus you could store a whopping 2 Gb of data, in a perfect network, or
256 MB.  My desktop at home has more DRAM, and has far better access
behavior.  So the network layer juggling is pointless.

The higher level juggling is still pointless.  Lets assume I still
have the 1 Gb link to the outside world, and the data round trip
latency is a minute (the amount of time data can be stored externally
before it comes back to me).  Thats still just 60 Gb of data, or 7.5
GB.  And I'm having to burn a 1 Gb link to do it!

If my external link is "ONLY" 100 Mb, and the latency/refresh time is
1 minute, thats 768 MB of data.

So who cares?  Why juggle when shelves hold so much more?

-- 
Nicholas C. Weaver                                 nweaver@cs.berkeley.edu