856 research outputs found
PEARL: a programmable virtual router platform
International audienceProgrammable routers supporting virtualization are a key building block for bridging the gap between new Internet protocols and their deployment in real operational networks. This article presents the design and implementation of PEARL, a programmable virtual router platform with relatively high performance. It offers high flexibility by allowing users to control the configuration of both hardware and software data paths. The platform makes use of fast lookup in hardware and software exceptions in commodity multicore CPUs to achieve highspeed packet processing. Multiple isolated packet streams and virtualization techniques ensure isolation among virtual router instances
FAIR: Forwarding Accountability for Internet Reputability
This paper presents FAIR, a forwarding accountability mechanism that
incentivizes ISPs to apply stricter security policies to their customers. The
Autonomous System (AS) of the receiver specifies a traffic profile that the
sender AS must adhere to. Transit ASes on the path mark packets. In case of
traffic profile violations, the marked packets are used as a proof of
misbehavior.
FAIR introduces low bandwidth overhead and requires no per-packet and no
per-flow state for forwarding. We describe integration with IP and demonstrate
a software switch running on commodity hardware that can switch packets at a
line rate of 120 Gbps, and can forward 140M minimum-sized packets per second,
limited by the hardware I/O subsystem.
Moreover, this paper proposes a "suspicious bit" for packet headers - an
application that builds on top of FAIR's proofs of misbehavior and flags
packets to warn other entities in the network.Comment: 16 pages, 12 figure
Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results
Fixed and mobile telecom operators, enterprise network operators and cloud
providers strive to face the challenging demands coming from the evolution of
IP networks (e.g. huge bandwidth requirements, integration of billions of
devices and millions of services in the cloud). Proposed in the early 2010s,
Segment Routing (SR) architecture helps face these challenging demands, and it
is currently being adopted and deployed. SR architecture is based on the
concept of source routing and has interesting scalability properties, as it
dramatically reduces the amount of state information to be configured in the
core nodes to support complex services. SR architecture was first implemented
with the MPLS dataplane and then, quite recently, with the IPv6 dataplane
(SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering
of packets across nodes to a general network programming approach, making it
very suitable for use cases such as Service Function Chaining and Network
Function Virtualization. In this paper we present a tutorial and a
comprehensive survey on SR technology, analyzing standardization efforts,
patents, research activities and implementation results. We start with an
introduction on the motivations for Segment Routing and an overview of its
evolution and standardization. Then, we provide a tutorial on Segment Routing
technology, with a focus on the novel SRv6 solution. We discuss the
standardization efforts and the patents providing details on the most important
documents and mentioning other ongoing activities. We then thoroughly analyze
research activities according to a taxonomy. We have identified 8 main
categories during our analysis of the current state of play: Monitoring,
Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path
Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL
Pyrazole-based analogs as potential antibacterial agents against methicillin-resistance staphylococcus aureus (MRSA) and its SAR elucidation
Methicillin-resistant Staphylococcus aureus (MRSA) is becoming lethal to humanity due to easy transmission and difficult-to-treat skin and flimsy diseases. The most threatening aspect is the rapid resistance development of MRSA to any approved antibiotics, including vancomycin. The development of new, efficient, and nontoxic drug candidate to fight against MRSA isolates is the need of the hour. The intriguing molecular structure and versatile bioactive pyrazole core attracting to development required novel antibiotics. This review presents the decade developments of pyrazole-containing derivatives with a broad antibacterial movement against diverged bacterial strains. In specific, we correlated the efficacy of structurally diversified pyrazole analogs against MRSA and discussed different angles of structure-activity relationship (SAR). The current survey highlights pyrazole hybrids' present scenario on MRSA studies, covering articles published from 2011 to 2020. This collective information may become an excellent platform to plan and develop new pyrazole-based small MRSA growth inhibitors with minimal side effects. (C) 2020 Elsevier Masson SAS. All rights reserved
Scripted Mobile Network Routing in a Contested Environment
Mobile wireless network protocols currently run on optimistic routing algorithms, adjusting node connectivity only when the chosen connectivity metrics, such as signal strength, pass beyond minimum thresholds. Optimistic routing has several weaknesses. Optimistic routing suffers from increased network overhead during increased frequency of node movement and increased node density per area, and optimistic routing also suffers from non-optimistic access change for individual nodes. The overall communication throughput of a network may be increased if the network topology change is scripted; a scripted plan can allow messages to travel along a more efficient topological path while creating less topology control traffic. This would increase the overall network bandwidth and may be an alternative solution to current network routing problems such as route loop creation. This thesis tested a network with scripted movement against an unscripted network in a simple network featuring mobility, for increases in bandwidth due to scripted node access changes over optimistic access changes. The results showed significant improvement in the data throughput in the scripted network when there were multiple overlapping networks contending for the same node
Design and Evaluation of Packet Classification Systems, Doctoral Dissertation, December 2006
Although many algorithms and architectures have been proposed, the design of efficient packet classification systems remains a challenging problem. The diversity of filter specifications, the scale of filter sets, and the throughput requirements of high speed networks all contribute to the difficulty. We need to review the algorithms from a high-level point-of-view in order to advance the study. This level of understanding can lead to significant performance improvements. In this dissertation, we evaluate several existing algorithms and present several new algorithms as well. The previous evaluation results for existing algorithms are not convincing because they have not been done in a consistent way. To resolve this issue, an objective evaluation platform needs to be developed. We implement and evaluate several representative algorithms with uniform criteria. The source code and the evaluation results are both published on a web-site to provide the research community a benchmark for impartial and thorough algorithm evaluations. We propose several new algorithms to deal with the different variations of the packet classification problem. They are: (1) the Shape Shifting Trie algorithm for longest prefix matching, used in IP lookups or as a building block for general packet classification algorithms; (2) the Fast Hash Table lookup algorithm used for exact flow match; (3) the longest prefix matching algorithm using hash tables and tries, used in IP lookups or packet classification algorithms;(4) the 2D coarse-grained tuple-space search algorithm with controlled filter expansion, used for two-dimensional packet classification or as a building block for general packet classification algorithms; (5) the Adaptive Binary Cutting algorithm used for general multi-dimensional packet classification. In addition to the algorithmic solutions, we also consider the TCAM hardware solution. In particular, we address the TCAM filter update problem for general packet classification and provide an efficient algorithm. Building upon the previous work, these algorithms significantly improve the performance of packet classification systems and set a solid foundation for further study
Guifi.net: characterization, data collection and selfmanagement of community
In this project, we are going to present an E2E (end to end) solution for the principal problems that normally impact the community networks and especially Guifinet. To introduce our solution, we were investigating how the Guifinet works internally (its network hierarchy, equipment used, IP configuration and also its financial system) and also how wireless technology works and their limitations. Once we analysed and detected all the potential issues, we performed a routing performance and QoS (quality or service) simulation in order to test two experimental protocol called BATMAN and OLSR to find the most suitable routing protocol for our approach. And finally, we presented our new Guifinet network concept basing in MPLS over OLSR
Quantifying the performance degradation of IPv6 for TCP in Windows and Linux Networking
Implementing IPv6 in modern client/server operating systems (OS) will have drawbacks of lower throughput as a result of its larger address space. In this paper we quantify the performance degradation of IPv6 for TCP when implementing in modern MS Windows and Linux operating systems (OSs). We consider Windows Server 2008 and Red Hat Enterprise Server 5.5 in the study. We measure TCP throughput and round trip time (RTT) using a customized testbed setting and record the results by observing OS kernel reactions. Our findings reported in this paper provide some insights into IPv6 performance with respect to the impact of modern Windows and Linux OS on system performance. This study may help network researchers and engineers in selecting better OS in the deployment of IPv6 on corporate networks
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