Patent attributes
A network packet analyzer according an embodiment includes a memory and one or more hardware processors. The memory stores a plurality of sets of training data in which semantics of one protocol field and one or more patterns indicating characteristics of variations of the parameters of the one protocol field are associated with each other. The hardware processors: captures a network packets and extracts a variable field whose parameter varies in time series; generates, based on the parameter varying in the time series in the variable field, one or more patterns indicating a characteristic of a variation of the parameter; and compares each of the one or more patterns with each of the one or more patterns of the training data and estimate the semantics of the variable field.