TODO

Bugs :
    When no peer is avalaible, the setup crash without the --no-boot option
    G : see below
    U : this is still a bug to be solved

To be done :
    Use an algorithm to choose which connections to keep and/or establish
    instead of pure randomness
    
    Find a name for the project : the projet is ( or should be ) independant
    from vifib, openvpn, babel, and so should the name; btw we aim to build a
    distributed, scalable, resilient VPN.... ( if it helps with the name )
    
    Replace comments at the beginning of functions with docstrings & give all
    fn docstrings
    
    Use the server events ( client connection/deconnection ) to do something
    useful
    
    In peers DB, remove some peers when they are too many of them -> remove the
    dead peers
    
    Use a timeout for the peersDB 
    G : removing the dead peers should be enough
    U : I was speaking of the server peers DB
    
    Specify a lease duration in ForwardViaUPnP
    
    Handle LAN internally in order not to have catastrophic results ....

To be discussed:
    G, J : To get traffic stats ( bytes in/out ), you can use
          /sys/class/net/interface/statistics/rx_bytes, etc...
        or /proc/net/dev/snmp6/interface ( all in one file ). This can be enough
        if used as follows: get traffic diff from last time we checked in order
        to choose which connection is significantly unused compared to others,
        and close it. Of course, too recent connections (i.e. those for which we
        have no previous stat) would be always kept.
        This should be combined with routing table (i.e. how many nodes are
        served by each tunnel), which is possibly redundant.
        ip6tables should be avoided if possible.
    U : Great !!!

    U : Babel seems to be very long to establish the routes : maybe we should
        tell him thant we are not on a wired network but on a mobile network ?
    G : babel establish routes quickly enough i'd say. There are two new
        options : hello and wireless, for hello_interval and treating all
        interfaces as wireless. However, treating an interface as wireless
        doesn't lessen the hello_interval, it only changes how babel estimates
        quality link, and cost.
    U : from babel web page : "When the Babel daemon detects a wired network, 
        it will use a larger interval between hellos".
        Moreover, it seems that the wireless option only means 
        "hostile environment" which seems best for a resilient network. 
        30 sec of hello interval seams also too much. The default value for
        babel is 4 sec (from babel man page).
        According to raphael's stats on the nexedi's server downtime, 
        45% of the problems dont last more than 2 minutes, 55% no more than
        3 minutes If it takes 2 min to detect a dead connection, then we wont be
        solving many problems with our overlay network

    U : The peer DB size should depend on the number of connection and the
        refresh time
    G : ?! I don't agree, the db size should be proportional ( with a factor
        like 0.01 or less ) to the total number of peers in the entire network,
        with maybe a max size.
    U : what we need to do  is to keep the randomness. For this, we need a big
        enought DB to ensure we can still choose a peer as if it was choosen 
        directly from the server. The requiered db size can be calculated from
        the number of connections and the refresh time.

    U : Remove the --no-boot option since we know when no node is avalaible
    G : the no-boot option is only useful when the server knows no peer,
        irl it should never happen, no-boot is a debug option
    U : Ok, but the server knows when no peers is avalaible, doesn't he ?
    G : Well when no peer is available the SQL request ( + next() method ) raise
        a StopIteration exception
    U : Well, I don't think this is a good thing. When not in debug, a node 
        cannot now if their is anyone else already connected

    G : don't reconnect to server each time we repopulate in peers_db ?
    U : From what I've read on the internet, when you create a server object,
        you don't connect to the server, You only connect to the server once you
        send a request for a methode and then you can automatically use the same
        connection for 15sec
    G : ok, it justs need testing ( for when some requests for the server will
        require to be plugged in the network )

    U : Use more than one boostrap node
    G : we'll use the server as a bootstrap node