Implementation and evaluation of an inline network measurement algorithm and its application to TCP-based service

In our previous studies, we proposed ImTCP, an inline network measurement technique that can obtain available bandwidth information of the network path between sender and receiver hosts continuously and in an inline fashion. We also introduced ImTCP-bg, a background TCP data transfer mechanism based on the measurement results of ImTCP. In the present paper, we report implementation issues of the proposed mechanisms on a FreeBSD system and evaluate them on an experiment network and in the actual Internet. We investigate the performance through the extensive experiments and verify that ImTCP can measure well the available bandwidth of the network path, independent of the degree of its change, and that ImTCP-bg can utilize the available bandwidth well, without degrading the performance of competing traffic. From these experiment results, we confirm the effectiveness of our concept, which is the inline network measurement technique, in an actual network.