1. A method for monitoring a plurality of communication dialogs occurring in a network of nodes, each dialog of said plurality of dialogs being effected by a transmission of one or more packets among two or more communicating nodes, each dialog of said plurality of dialogs complying with a different predefined communication protocol selected from among a plurality of protocols available in said network, said plurality of dialogs representing multiple different protocols from among said plurality of available protocols, said method comprising: passively, in real time, and on an ongoing basis, detecting the contents of packets; from the detected contents of said packets, identifying all of the dialogs of said plurality of communication dialogs occurring in said network; deriving from said detected contents of said packets, information about the identified dialogs; and for each of the identified dialogs, storing the derived information about that identified dialog.