> i'm wondering about the difference between the options
> "maximum number of  connections/seconds" (alias %cN) and
> "number of multiple connections" (alias cN).

You can have two connections ar a time (c2) but 20 
connexions/seconds because of the speed (0.1 seconds to 
process a request). That's why %c has been implemented, to 
reduce the connection/disconnection speed