[tor-bugs] #6401 [Analysis]: Update Tor network models from CSET paper

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#6401: Update Tor network models from CSET paper
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 Reporter:  robgjansen                              |          Owner:  robgjansen
     Type:  task                                    |         Status:  new       
 Priority:  normal                                  |      Milestone:            
Component:  Analysis                                |        Version:            
 Keywords:  simulation, performance, network model  |         Parent:            
   Points:                                          |   Actualpoints:            
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Comment(by robgjansen):

 After thinking about this, I think we have '''too many web clients'''.

 We originally wanted ~95% of our ''connections'' to be web, according to
 the now outdated [http://freehaven.net/anonbib/cache/mccoy-pet2008.pdf
 shining light paper] from McCoy etal. Since each of our simple clients
 only create one connection, we simply configured ~95% of our ''clients''
 as web, and moved on.

 However, web page downloads usually require many, many GET requests for
 all the embedded images and css files, etc - 45-ish on average,
 [https://developers.google.com/speed/articles/web-metrics according to
 Google]. Google also says that the GETs would be directed to 8 different
 hosts, on average. So a single web page would have counted as about 8
 separate connections in the Mccoy study.

 But each page only counts as a single connection in our model, i.e. each
 web client in our simulation actually represents 8 connections and all the
 data they download with a single connection. So, the 95% of the clients we
 have could be off by a factor of 8, roughly. This might explain why the
 load balance is slightly off in our experiments above.

 '''So, what do we really want?'''

 Ideally, a client that does what we actually want, i.e. a web browser that
 downloads embedded objects with several connections in parallel. Thats
 item 3 in the ticket description. Since the browser client isn't ready
 yet, we'll make due with our simpler single-GET client. The connection
 balance might not be right, but hopefully the load will.

 We don't just want to cut our web clients by a factor of 8, because each
 of our web clients are likely representing several real clients anyway (we
 are likely downloading more webpages that a real client would). But, it
 seems reasonable to drop them from 2300 down to 1500. This should help
 move the load where we actually want it.

 Sorry this got long. Not sure if anyone even reads it... but I'd love
 comments.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6401#comment:6>
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