Research into providing different levels of network Quality of Service (QoS) often assumes that there is a large market for QoSsensitive applications that will be fulfilled once QoS-enabled networks have been deployed. Multiplayer networked games are an example of such an application that requires QoS, and hence will only become popular if QoS is made widely available. The prima facie evidence, however, is that games are already popular, in spite of the existing QoS-free best-effort Internet. Networked games may have become popular despite the lack of QoS because players “make do ” with what is available to them. Such popularity is a double-edged sword. It may mean that there is a demand, as yet unfulfilled, from game players for QoS-enabled networks. On the other hand, it may mean that players have become accustomed to playing games without QoS, and therefore might be

On September 26, 1999, a musical performance, taking place at McGill University, was transmitted to an audience at New York University, over the Internet. While Internet streaming audio technologies have been in use for several years, what made this event unique was the audience's experience of uninterrupted, intermediate quality, multichannel audio (AC-3). In order to achieve this result, a custom system was developed employing both TCP and UDP protocols, and providing its own buffering and retransmission algorithms. The motivation for this approach is explored, and experiments justifying the decisions made are explained. = Appeared in Journal of the Audio Engineering Society,July-August, 2000. 2 1 Introduction The growth of the Internet has not only reshaped our work lives, but, in recent years, has also begun to affect and redefine various areas of entertainment, in particular, that of music. Until the last decade, the idea of downloading music to one's home, at great convenienc...

In some contexts it may be useful to predict the latency for short TCP transfers. For example, a Web server could automatically tailor its content depending on the network path to each client, or an "opportunistic networking" application could improve its scheduling of data transfers.

Abstract not found

This thesis presents practical studies of the TCP performance problems caused by the asymmetric nature of ADSL connections. Previously, it has been shown on other types of asymmetric links that TCP throughput may be reduced due to a variable and imperfect ACK feedback. The upstream capacity of ADSL products in general does not disturb the ACK feedback mechanism, but we analyze and document that TCP traffic across ADSL in fact is affected by the asymmetric nature of ADSL, when utilizing the upstream capacity. For a single user ADSL installation it is manageable to avoid upstream congestion, but for larger networks, connected to the Internet by ADSL, the rise of peer-to-peer file sharing applications may result in a permanently congested upstream link. The thesis provides evidence that the achievable downstream throughput is reduced significantly in case of a saturated upstream link. Saturation of the upstream link introduces a high queueing delay that effectively renders the connection useless for interactive and other delay-sensitive applications (like VoIP).

Abstract not found