Abstract: Provided is a communication device for measuring a usable bandwidth without delay in transmission of primary data. The relay device according to an embodiment of the present invention, when measuring a usable bandwidth in communication with another relay device, processes a user packet including a user data to be transmitted to the other relay device so as to be changed into a specific packet size while the user data is maintained as it is, and utilizes it as a measurement packet. Accordingly, even though it is a measurement packet for performing measurement of a bandwidth, since it includes user data, it may be treated in the same manner as a user packet thereby enabling an efficient use of a communication network in communication. Also, even though UDP is used, since a usable bandwidth can be measured, it is possible to measure a bandwidth even though streaming data is distributed while preventing any influences on the distribution.

Abstract: Provided is a communication device for measuring a usable bandwidth without delay in transmission of primary data. The relay device according to an embodiment of the present invention, when measuring a usable bandwidth in communication with another relay device, processes a user packet including a user data to be transmitted to the other relay device so as to be changed into a specific packet size while the user data is maintained as it is, and utilizes it as a measurement packet. Accordingly, even though it is a measurement packet for performing measurement of a bandwidth, since it includes user data, it may be treated in the same manner as a user packet thereby enabling an efficient use of a communication network in communication. Also, even though UDP is used, since a usable bandwidth can be measured, it is possible to measure a bandwidth even though streaming data is distributed while preventing any influences on the distribution.