Methods, apparatus, systems and articles of manufacture are disclosed to identify a first request having a first source port number, from a device, determining whether a second request, having a second source port number, is within a threshold number of ports from the first source port number, group the first and the second requests as a first session when the second source port number is within the threshold number of ports from the first source port number, and generate session windows, the session windows including the threshold number of ports, wherein the session windows are applied to lowest and highest source port numbers associated with a current session.