19. The method according to claim 15 , wherein said evaluating further comprises calculating two or more progressive similarity scores each with respect to a different instant during a progress of a real-time conversational media session, wherein each of said scores corresponds to the similarity between the packet arrival times associated with the real-time conversational media session data which were available at the corresponding instant and the reference data item, and wherein said evaluating further comprises evaluating progressive similarity between the real-time conversational media session data and the reference data item based upon the two or more progressive similarity scores.
19. The method according to claim 15 , wherein said evaluating further comprises calculating two or more progressive similarity scores each with respect to a different instant during a progress of a real-time conversational media session, wherein each of said scores corresponds to the similarity between the packet arrival times associated with the real-time conversational media session data which were available at the corresponding instant and the reference data item, and wherein said evaluating further comprises evaluating progressive similarity between the real-time conversational media session data and the reference data item based upon the two or more progressive similarity scores. 44. The method according to claim 19 , wherein said evaluating comprises concluding based upon the two or more progressive similarity scores whether the real-time conversational media session and the reference data item are similar, dissimilar or that further progressive similarity scores are necessary to conclude similarity or dissimilarity.