[01/26/2012]

What advantages do computer networks provide us?
-- communication
-- backups
-- redundancy / no single points of failure
-- multiple users can access same services
-- remote access / laziness
-- parallel/distribution computation
-- use each piece of hardware for what it's best at
-- centralized administration

What do we use computer networks for?
-- communication
-- data transfer
-- multi-player games (WoW)
-- data collection
-- file sharing / anonymity
-- sharing printers, network drives, resources
-- remote administration
-- remote execution
-- e-commerce
-- collaboration
-- education (online courses, K-12)
-- everything!


Design protocol to get secret message to name on secret message

-- message can only go to an adjacent neighbor
-- ensure message is not read along the way
-- ensure message is not altered
-- ensure message is not lost
-- ensure message gets to its destination

-- staple the paper to ensure it doesn't get read / altered
-- ask each adjacent person if s/he is the recipient
---- if so, hand it off to that person
---- if not:

     first locate the person by adjacent-question-asking

     once found, send the path back somehow

     if not found, send an NOT FOUND error back somehow

         somehow: everyone keeps track
                  of who asked them

                  keep track of who told
                   them it was found

       (keep track by writing on the packet?)




   approach that sends the packet

   -- if we had a "seating chart," then each hop would know
         (single point of failure?)

-- how does the sender know (guarantee)
   that the recipient has received the msg?



examples of client/server communication?
-- web server
-- file server
-- email server
-- print server
-- authentication server
-- ssh
-- X
-- server performs/records a transaction
-- database
-- proxy
-- date/time server
-- etc.