1. At least one computer-readable storage medium having instructions stored thereon that, when executed by a computing device, cause the computing device to perform acts, comprising: obtaining a set of middlebox error reports; separating spurious and duplicate middlebox error reports from a filtered sub-set of the middlebox error reports; correlating the filtered sub-set of the middlebox error reports with other middlebox-related data to produce correlated data; and, performing inference analysis on the correlated data to estimate middlebox reliability.