<title>Rate-matching packet scheduler for real-rate applications</title>

Abstract

A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine-grain reallocation of bandwidth for flows with variable-bit-rate requirements. Unfortunately, today's packet schedulers either do not support rate and timing sensitive flows, or do so with reservation systems that are relatively coarse-grain and inflexible. This paper makes two contributions. First it shows how bandwidth requirements can be inferred directly from real-rate flows, without requiring explicit specifications from the application. Second, it presents the design, implementation and performance evaluation of a rate-matching packet scheduler that uses these inferred requirements to automatically and dynamically control the bandwidth allocation to flows.

Urica

“…teract with the system. Contemporary real-time multimedia systems often utilize adaptive techniques alongside traditional scheduling and admission control mechanisms in order to meet Quality of Service (QoS) requirements [1,6,20,25]. Factors such as server overload or congestion within the network can trigger degradation in the quality of the multimedia content that is provided to the client while meeting real-time constraints.…”

Infopipes: An abstraction for multimedia streaming

“…The first, which pre-dates the development of Infopipes themselves, is the design and implementation of a series of video players that stream video over the Internet, adapting their behaviour to make the best possible use of the available bandwidth Cowan et al 1995;Inouye et al 1997;Koster 1996;Staehli et al 1995). The second thread is related to the underlying technologies that support streaming media, in particular, adaptive and rate-sensitive resource scheduling (Li et al 2000;Steere et al 1999a;Steere et al 1999b) and congestion control (Cen et al 1998;Li et al 2001a;Li et al 2001b). It is these technologies that enable us to design and build the Infopipes that are necessary for interesting applications.…”