With the spread of broadband access lines, many services making efficient use of them such as video streaming services have appeared. The popularity of these services can cause problems such as the shortage of the Internet backbone capacity, so it is important to detect increasing traffic which cause these problems early. In this paper, we propose an early detection method (partial aggregation method) of increasing traffic under per-subnet based distributed traffic monitoring. The method estimates future overall traffic volume by taking account of estimated traffic volume in all subnets and the estimated number of subnets generating increasing traffic. We compare the proposed method to a previous method (aggregation method) which takes account of estimated traffic volume in all subnets only. The results show that the partial aggregation method can detect increasing traffic earlier than the aggregation method by a maximum of 90 days.
