Active networks: an evolution of the internet

Active Networks can be seen as an evolution of the classical model of packet-switched networks. The traditional and ”passive” network model is based on a static definition of the network node behaviour. Active Networks propose an “active” model where the intermediate nodes (switches and routers) can load and execute user code contained in the data units (packets). Active Networks are a programmable network model, where bandwidth and computation are both considered shared network resources. This approach opens up new interesting research fields. This paper gives a short introduction of Active Networks, discusses the advantages they introduce and presents the research advances in this field

The exokernel operating system architecture

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 115-120).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.On traditional operating systems only trusted software such as privileged servers or the kernel can manage resources. This thesis proposes a new approach, the exokernel architecture, which makes resource management unprivileged but safe by separating management from protection: an exokernel protects resources, while untrusted application-level software manages them. As a result, in an exokernel system, untrusted software (e.g., library operating systems) can implement abstractions such as virtual memory, file systems, and networking. Themain thrusts of this thesis are: (1) how to build an exokernel system; (2) whether it is possible to build a real one; and (3) whether doing so is a good idea. Our results, drawn from two exokernel systems [25, 48], show that the approach yields dramatic benefits. For example, Xok, an exokernel, runs a web server an order of magnitude faster than the closest equivalent on the same hardware, common unaltered Unix applications up to three times faster, and improves global system performance up to a factor of five. The thesis also discusses some of the new techniques we have used to remove the overhead of protection. Themost unusual technique, untrusted deterministic functions, enables an exokernel to verify that applications correctly track the resources they own, eliminating the need for it to do so. Additionally, the thesis reflects on the subtle issues in using downloaded code for extensibility and the sometimes painful lessons learned in building three exokernel-based systems.by Dawson R. Engler.Ph.D

One-Sided Communication for High Performance Computing Applications

Thesis (Ph.D.) - Indiana University, Computer Sciences, 2009Parallel programming presents a number of critical challenges to application developers. Traditionally, message passing, in which a process explicitly sends data and another explicitly receives the data, has been used to program parallel applications. With the recent growth in multi-core processors, the level of parallelism necessary for next generation machines is cause for concern in the message passing community. The one-sided programming paradigm, in which only one of the two processes involved in communication actively participates in message transfer, has seen increased interest as a potential replacement for message passing. One-sided communication does not carry the heavy per-message overhead associated with modern message passing libraries. The paradigm offers lower synchronization costs and advanced data manipulation techniques such as remote atomic arithmetic and synchronization operations. These combine to present an appealing interface for applications with random communication patterns, which traditionally present message passing implementations with difficulties. This thesis presents a taxonomy of both the one-sided paradigm and of applications which are ideal for the one-sided interface. Three case studies, based on real-world applications, are used to motivate both taxonomies and verify the applicability of the MPI one-sided communication and Cray SHMEM one-sided interfaces to real-world problems. While our results show a number of short-comings with existing implementations, they also suggest that a number of applications could benefit from the one-sided paradigm. Finally, an implementation of the MPI one-sided interface within Open MPI is presented, which provides a number of unique performance features necessary for efficient use of the one-sided programming paradigm

Virtualization of network I/O on modern operating systems

Network I/O of modern operating systems is incomplete. In this networkage, users and their applications are still unable to control theirown traffic, even on their local host. Network I/O is a sharedresource of a host machine, and traditionally, to address problemswith a shared resource, system research has virtualized the resource.Therefore, it is reasonable to ask if the virtualization can providesolutions to problems in network I/O of modern operating systems, inthe same way as the other components of computer systems, such asmemory and CPU. With the aim of establishing the virtualization ofnetwork I/O as a design principle of operating systems, thisdissertation first presents a virtualization model, hierarchicalvirtualization of network interface. Systematic evaluation illustratesthat the virtualization model possesses desirable properties forvirtualization of network I/O, namely flexible control granularity,resource protection, partitioning of resource consumption, properaccess control and generality as a control model. The implementedprototype exhibits practical performance with expected functionality,and allowed flexible and dynamic network control by users andapplications, unlike existing systems designed solely for systemadministrators. However, because the implementation was hardcoded inkernel source code, the prototype was not perfect in its functionalcoverage and flexibility. Accordingly, this dissertation investigatedhow to decouple OS kernels and packet processing code throughvirtualization, and studied three degrees of code virtualization,namely, limited virtualization, partial virtualization, and completevirtualization. In this process, a novel programming model waspresented, based on embedded Java technology, and the prototypeimplementation exhibited the following characteristics, which aredesirable for network code virtualization. First, users program inJava to carry out safe and simple programming for packetprocessing. Second, anyone, even untrusted applications, can performinjection of packet processing code in the kernel, due to isolation ofcode execution. Third, the prototype implementation empirically provedthat such a virtualization does not jeopardize system performance.These cases illustrate advantages of virtualization, and suggest thatthe hierarchical virtualization of network interfaces can be aneffective solution to problems in network I/O of modern operatingsystems, both in the control model and in implementation

Flexible and efficient sharing of protected abstractions

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 73-76).by George M. Candea.S.B.and M.Eng

Building an active node on the Internet

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 63-65).by David M. Murphy.M.Eng

Netzwerkmanagement und Hochgeschwindigkeits- Kommunikation. Teil XVII

Der vorliegende Interne Bericht enthält die Beiträge zum Seminar "Netzwerk-Management und Hochgeschwindigkeits- Kommunikation, das im Wintersemester 1997/98 zum siebzehnten Mal stattgefunden hat. Die Themenauswahl kann grob in folgende Blöcke gegliedert werden: Ein Block beschäftigt sich mit drahtlosen Kommunikations- protokollen. Der erste Beitrag widmet sich drahtlosem ATM, während ein zweiter Beitrag Möglichkeiten der Satelliten- kommunikation vorstellt. Außerdem werden Sicherheitsaspekte im GSM diskutiert. Ein Beitrag stellt das Transis-System zur zuverlässigen, geordneten Gruppenkommunikation über IP vor. Ein dritter Block präsentiert Möglichkeiten der Unterstützung schneller Kommunikation. Hier werden etwa die sogenannten xDSL-Techniken vorgestellt. Außerdem wird der Firewire-Ansatz konventionellen Bussystemen in Rechnern gegenübergestellt. Schließlich widmen sich zwei Beiträge neuartigen Konzepten im Betriebssystem-Bereich, welche eine Kommunikationsunter- stützung versprechen. Ein Block mit dem Schwerpunkt auf neuen Netzkonzepten geht in zwei Beiträgen auf sogenannte Aktive Netzwerke ein. Außerdem wird das in den USA betriebene Internet2 vorgestellt. Ein letzter Block befaßt sich mit Fragen des Managements. Hier stehen die DISMAN- und die SNMPv3-Arbeitsgruppe im Vordergrund. Außerdem wird in einem Beitrag das Telecommunication Management Network (TMN) vorgestellt

Prolac--a language for protocol compilation

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 81-83).by Eddie Kohler.M.S

Parallel and distributed processing in high speed traffic monitoring

This thesis presents a parallel and distributed approach for the purpose of processing network traffic at high speeds. The proposed architecture provides the processing power required to run one or more traffic processing applications at line rates by means of processing full packets at multi-gigabits speeds using a parallel and distributed processing environment. Moreover, the architecture is flexible and scalable to future needs by supporting heterogeneous processing nodes such as different hardware architectures or different generations of the same hardware architecture. In addition to the processing, flexibility, and scalability features, our architecture provides an easy-to-use environment with the help of a new programming language, called FPL, for traffic processing in a distributed environment. The language and its compiler come to hide specific programming details when using heterogeneous systems and a distributed environment.UBL - phd migration 201

ASHs: Application-Specific Handlers for High-Performance Messaging

Application-specific safe message handlers (ASHs) are designed to provide applications with hardware-level network performance. ASHs are user-written code fragments that safely and efficiently execute in the kernel in response to message arrival. ASHs can direct message transfers (thereby eliminating copies) and send messages (thereby reducing send-response latency). In addition, the ASH system provides support for dynamic integrated layer processing (thereby eliminating duplicate message traversals) and dynamic protocol composition (thereby supporting modularity). ASHs provide this high degree of flexibility while still providing network performance as good as, or (if they exploit application-specific knowledge) even better than, hard-wired in-kernel implementations. A combination of user-level microbenchmarks and end-to-end system measurements using TCP demonstrate the benefits of the ASH system