Measurement based PPStream client behavior analysis

Abstract

PPStream is one of the most popular p2p media streaming applications. Our early study finds the design philosophy for both PPStream and PPLive is different. As a preliminary study for further deeply modeling, in this paper we try to study PPStream client behavior based on our recent measurement dataset. The report focuses on several aspects of peer: some specific mechanisms applied in the new version of PPStream client; overlay network environment of the system including the round-trip time, packet loss and replication; the concurrency of sessions, fetching buffer blocks and chunks; the chunk fetching behavior as well as the reciprocity between our client and its neighbors. We think our finds and discussions are of great values to further studies for researchers.

A Congestion Control Protocol in P2P Networks

“…Since the traffic is spread on the whole network, we assume the congestion happens in the access network instead in the backbone network. Furthermore, as found in [10], PPStream has migrated its underlying transport protocol to UDP in 2008. Thus, we assume that a P2P application adopts UDP as underlying its transport protocol and discuss the congestion problem when peers download data from each other in P2P environment.…”

“…We name the protocol used by each of those E2E connections as the underlying protocol on which the M2M transport works. UDP seems to be a more appropriate underneath protocol than TCP since almost all P2P streaming networks (e.g., live and VoD) have migrated the underneath protocol to UDP in their M2M transport protocol based on our measurements [10]. Moreover, BitTorrent is currently trying to do similar actions [5].…”

“…For unknown reason, most of P2P applications move their transport protocol from TCP to UDP protocol. For example, PPstream and PPlive have changed their transport protocol from TCP to UDP in 2008 [5]. Bittorent also plan to adopt UDP as its transport protocol [2].…”