Bounding Peer-to-Peer Upload Traffic in Client Networks

Peer-to-peer technique has now become one of the major techniques to exchange digital content between peers of the same interest. However, as the amount of peer-to-peer traffic increases, a network administrator would like to control the network resources consumed by peer-to-peer applications. Due to the use of random ports and protocol encryption, it is hard to identify and apply proper control policies to peer-to-peer traffic. How do we properly bound the peer-to-peer traffic and prevent it from consuming all the available network resources? In this paper, we propose an algorithm that tries to approximately bound the network resources consumed by peer-to-peer traffic without examining packet payloads. Our methodology especially focuses on upload traffic for that the upload bandwidth for an ISP are usually more precious than download bandwidth. The method is constructed in two stages. First, we observe several traffic characteristics of peer-to-peer applications and traditional client-server based Internet services. We also observe the generic traffic properties in a client network. Then, based on the symmetry of network traffic in both temporal and spatial domains, we propose to use a bitmap filter to bound the network resources consumed by peer-to-peer applications. The proposed algorithm takes only constant storage and computation time. The evaluation also shows that with a small amount of memory, the peer-to-peer traffic can be properly bounded close to a predefined amount.