blog/data/2015-05-01-telefonsamtalelagring.txt

   1 Title: What would it cost to store all phone calls in Norway?
   2 Tags: english, personvern, surveillance
   3 Date: 2015-05-01 19:30
   4
   5 <p>Many years ago, a friend of mine calculated how much it would cost
   6 to store the sound of all phone calls in Norway, and came up with the
   7 cost of around 20 million NOK (2.4 mill EUR) for all the calls in a
   8 year.  I got curious and wondered what the same calculation would look
   9 like today.  To do so one need an idea of how much data storage is
  10 needed for each minute of sound, how many minutes all the calls in
  11 Norway sums up to, and the cost of data storage.</p>
  12
  13 <p>The 2005 numbers are from
  14 <a href="http://www.digi.no/analyser/2005/10/04/vi-prater-stadig-mindre-i-roret">digi.no</a>,
  15 the 2012 numbers are from
  16 <a href="http://www.nkom.no/aktuelt/nyheter/fortsatt-vekst-i-det-norske-ekommarkedet">a
  17 NKOM report</a>, and I got the 2013 numbers after asking NKOM via
  18 email.  I was told the numbers for 2014 will be presented May 20th,
  19 and decided not to wait for those, as I doubt they will be very
  20 different from the numbers from 2013.</p>
  21
  22 <p>The amount of data storage per minute sound depend on the wanted
  23 quality, and for phone calls it is generally believed that 8 Kbit/s is
  24 enough.  See for example a
  25 <a href="http://www.cisco.com/c/en/us/support/docs/voice/voice-quality/7934-bwidth-consume.html#topic1">summary
  26 on voice quality from Cisco</a> for some alternatives.  8 Kbit/s is 60
  27 Kbytes/min, and this can be multiplied with the number of call minutes
  28 to get the storage requirements.</p>
  29
  30 <p>Storage prices varies a lot, depending on speed, backup strategies,
  31 availability requirements etc.  But a simple way to calculate can be
  32 to use the price of a TiB-disk (around 1000 NOK / 120 EUR) and double
  33 it to take space, power and redundancy into account.  It could be much
  34 higher with high speed and good redundancy requirements.</p>
  35
  36 <p>But back to the question, What would it cost to store all phone
  37 calls in Norway?  Not much.  Here is a small table showing the
  38 estimated cost, which is within the budget constraint of most medium
  39 and large organisations:</p>
  40
  41 <table border="1">
  42 <tr><th>Year</th><th>Call minutes</th><th>Size</th><th>Price in NOK / EUR</th></tr>
  43 <tr><td>2005</td><td align="right">24 000 000 000</td><td align="right">1.3 PiB</td><td align="right">3 mill / 358 000</td></tr>
  44 <tr><td>2012</td><td align="right">18 000 000 000</td><td align="right">1.0 PiB</td><td align="right">2.2 mill / 262 000</td></tr>
  45 <tr><td>2013</td><td align="right">17 000 000 000</td><td align="right">950 TiB</td><td align="right">2.1 mill / 250 000</td></tr>
  46 </table>
  47
  48 <p>This is the cost of buying the storage.  Maintenance need to be
  49 taken into account too, but calculating that is left as an exercise
  50 for the reader.  But it is obvious to me from those numbers that
  51 recording the sound of all phone calls in Norway is not going to be
  52 stopped because it is too expensive.  I wonder if someone already is
  53 collecting the data?</p>