Advances in Internet Quality of Service

We describe recent advances in theories and architecture that support performance guarantees needed for quality of service networks. We start with deterministic computations and give applications to integrated services, differentiated services, and playback delays. We review the methods used for obtaining a scalable integrated services support, based on the concept of a stateless core. New probabilistic results that can be used for a statistical dimensioning of differentiated services are explained; some are based on classical queuing theory, while others capitalize on the deterministic results. Then we discuss performance guarantees in a best effort context; we review: methods to provide some quality of service in a pure best effort environment; methods to provide some quality of service differentiation without access control, and methods that allow an application to control the performance it receives, in the absence of network support

Congestion-aware caching and search in information-centric Networks

ABSTRACT The performance of in-network caching in informationcentric networks, and of cache networks more generally, is typically characterized by network-centric performance metrics such as hit rate and hop count, with approaches to locating and caching content evaluated and optimized for these metrics. We believe that user-centric performance metrics, in particular the delay from when a content request is made by the user to the time at which the requested content has been completely downloaded, are also important. For such metrics, performance is often determined by link capacity constraints and network congestion. We investigate network cache management and search policies that account for path-level (content-server to content-requestor) congestion and file popularity in order to directly minimize user-centric, content-download delay. Through simulation, we find that our policies yield significantly better download delay performance than existing policies, even though these existing policies provide better performance according to traditional metrics such as cache hit rate and hop count

Taxonomy of Coding Techniques for Efficient Network Communications

Internet Research Task Force, Request For Comments (RFC) 8406, https://datatracker.ietf.org/doc/rfc8406/This document summarizes recommended terminology for Network Coding concepts and constructs. It provides a comprehensive set of terms in order to avoid ambiguities in future IRTF and IETF documents on Network Coding. This document is the product of the Coding for Efficient Network Communications Research Group (NWCRG), and it is in line with the terminology used by the RFCs produced by the Reliable Multicast Transport (RMT) and FEC Framework (FECFRAME) IETF working groups

Network support for applications requiring quality of service in heterogeneous environments

Group communication, be it one-to-many (such as TV broadcasting) or many-to-many (such as teleconferencing) is becoming increasingly important because it enables the widespread dissemination of information (such as in today\u27s Word Wide Web) and the collaboration between remote groups. This kind of communication can be supported efficiently in digital networks through multicasting, a technique of non-redundant simultaneous data transmission from a sender to a set of receivers. Multicast applications such as voice and video require Quality of Service guarantees (such as maximum packet delay, packet loss probability), which can be provided by reserving network resources. In this dissertation we propose solutions to several critical problems of multicasting in heterogeneous environments: differences in network resource availability, differences in receiver Quality of Service requirements, differences in network resource availability and differences in resource reservation protocols. In the first part of the dissertation we consider the problem of resource reservation for multicast sessions in the context of both network and receiver heterogeneity. We develop centralized and distributed algorithms that accommodate this heterogeneity by performing a differentiated per-link resource reservation. We apply these algorithms in the context of packetized voice and MPEG video multicast connections over wide area networks. We find that our algorithms enable a network to carry as much as a 50% more traffic compared to the case where the network does not accommodate heterogeneity. In the second part of the dissertation we present algorithms for local (link) admission control and resource reservation at an Earliest Deadline First packet scheduler that provides heterogeneous packet delay guarantees at a link. When the data transmission is characterized by piecewise linear traffic envelopes, we show that the algorithms have very low computational complexity and thus, practical applicability. In the third part of the dissertation we focus on resource reservation protocols in the heterogeneous environment of IP over ATM networks. We describe a method for establishing reservations in the ATM network for IP flows (named ATM shortcutting). This method provides better performance to IP flows by avoiding the IP processing of IP packets, and better utilization of ATM network resources. In the last part of the dissertation we quantify the improvement in utilization of IP/ATM network when using ATM shortcutting. We present methods to evaluate this benefit given an IP/ATM network topology, link capacities and traffic patterns. We use this methods in simulation experiments using random networks. These experiments indicate that in many cases ATM shortcutting brings benefits in network utilization when it decreases the average length of network routes