Patent ID: 7606877

Claim:
A method of recognizing a transaction for a billing apparatus, comprising: receiving a duplicated hyper text transfer protocol (HTTP) request from a packet duplication apparatus, wherein the duplicated HTTP request is a duplication data of a HTTP request being transmitted from a user terminal to a proxy server via the packet duplication apparatus and is duplicated by the packet duplication apparatus; extracting an access address from the duplicated HTTP request; generating a first hash value based on the access address and a predetermined hash function; receiving a duplicated HTTP response from the packet duplication apparatus, wherein the duplicated HTTP response is a duplication data of a converted HTTP response being transmitted from a content server to the user terminal via the packet duplication apparatus and is duplicated by the packet duplication apparatus; extracting a second hash value from the duplicated HTTP response; comparing the first hash value with the second hash value; and determining the HTTP request and the converted HTTP response as a transaction if the first hash value is the same as the second hash value, wherein the transaction is a pair of the HTTP request and the converted HTTP response: wherein in order to generate the converted HTTP response including the second hash value, the proxy server is configured to: receive the HTTP request; generate the second hash value based on the access address and the predetermined hash function; transmit the HTTP request to the content server corresponding to the access address; receive an original HTTP response corresponding to the HTTP request from the content server; and insert the second hash value into a header of the original HTTP response so as to generate the converted HTTP response.