In this section on related studies, signature-based analysis
systems will be introduced that are existing studies on
analyzing HTTP traffic according to application. In study [7], 5
tuple information (Source IP, Destination IP, Source Port,
Destination Port, Protocol) and User-Agent information were
first extracted in HTTP traffic. It created flow by performing
grouping based on the 5 tuple information and conducted
analysis for each flow and packet. For the purpose of analyzing
the application in HTTP traffic, characteristics of User-Agent
were examined. User-Agent has atypical characteristics that are
different according to the OS of client and application version.
Despite the fact that it has atypical characteristic, it was found
that a certain pattern exists in the User-Agent value. In study
[7], 58 regular expression type patterns were manually created
by examining the pattern of User-Agent. Through the created
patterns, application identifier is extracted from User-Agent.