A test method for Internet-Protocol packet networks that verifies the
proper functioning of a dynamic pinhole filtering implementation as well
as quantifying network vulnerability statistically, as pinholes are
opened and closed is described. Specific potential security
vulnerabilities that may be addressed through testing include: 1)
excessive delay in opening pinholes, resulting in an unintentional denial
of service; 2) excessive delay in closing pinholes, creating a closing
delay window of vulnerability; 3) measurement of the length of various
windows of vulnerability; 4) setting a threshold on a window of
vulnerability such that it triggers an alert when a predetermined value
is exceeded; 5) determination of incorrectly allocated pinholes,
resulting in a denial of service; 6) determining the opening of
extraneous pinhole/IP address combinations through a firewall which
increase the network vulnerability through unrecognized backdoors; and 7)
determining the inability to correlate call state information with
dynamically established rules in the firewall.