505 research outputs found
A Data Distribution Service in a hierarchical SDN architecture: implementation and evaluation
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Software-defined networks (SDNs) have caused a paradigm shift in communication networks as they enable network programmability using either centralized or distributed controllers. With the development of the industry and society, new verticals have emerged, such as Industry 4.0, cooperative sensing and augmented reality. These verticals require network robustness and availability, which forces the use of distributed domains to improve network scalability and resilience. To this aim, this paper proposes a new solution to distribute SDN domains by using Data Distribution Services (DDS). The DDS allows the exchange of network information, synchronization among controllers and auto-discovery. Moreover, it increases the control plane robustness, an important characteristic in 5G networks (e.g., if a controller fails, its resources and devices can be managed by other controllers in a short amount of time as they already know this information). To verify the effectiveness of the DDS, we design a testbed by integrating the DDS in SDN controllers and deploying these controllers in different regions of Spain. The communication among the controllers was evaluated in terms of latency and overhead.Postprint (author's final draft
NetFPGA: status, uses, developments, challenges, and evaluation
The constant growth of the Internet, driven by the demand for timely access to data center networks; has meant
that the technological platforms necessary to achieve this purpose are outside the current budgets. In this order to make and
validate relevant, timely and relevant contributions; it is necessary that a wider community, access to evaluation,
experimentation and demonstration environments with specifications that can be compared with existing networking
solutions. This article introduces the NetFPGA, which is a platform to develop network hardware for reconfigurable and
rapid prototyping. Itâs introduces the application areas in high-performance networks, advantages for traffic analysis,
packet flow, hardware acceleration, power consumption and parallel processing in real time. Likewise, it presents the
advantages of the platform for research, education, innovation, and future trends of this platform. Finally, we present a
performance evaluation of the tool called OSNT (Open-Source Network Tester) and shows that OSNT has 95% accuracy
of timestamp with resolution of 10ns for the generation of TCP traffic, and 90% efficiency capturing packets at 10Gbps of
full line-rate
On the Exploration of FPGAs and High-Level Synthesis Capabilities on Multi-Gigabit-per-Second Networks
Tesis doctoral inĂ©dita leĂda en la Universidad AutĂłnoma de Madrid, Escuela PolitĂ©cnica Superior, Departamento de TecnologiÌa ElectroÌnica y de las Comunicaciones. Fecha de lectura: 24-01-2020Traffic on computer networks has faced an exponential grown in recent years.
Both links and communication equipment had to adapt in order to provide
a minimum quality of service required for current needs. However, in recent
years, a few factors have prevented commercial off-the-shelf hardware from
being able to keep pace with this growth rate, consequently, some software tools are
struggling to fulfill their tasks, especially at speeds higher than 10 Gbit/s. For this reason,
Field Programmable Gate Arrays (FPGAs) have arisen as an alternative to address the
most demanding tasks without the need to design an application specific integrated
circuit, this is in part to their flexibility and programmability in the field. Needless to say,
developing for FPGAs is well-known to be complex. Therefore, in this thesis we tackle
the use of FPGAs and High-Level Synthesis (HLS) languages in the context of computer
networks. We focus on the use of FPGA both in computer network monitoring application
and reliable data transmission at very high-speed. On the other hand, we intend to shed
light on the use of high level synthesis languages and boost FPGA applicability in the
context of computer networks so as to reduce development time and design complexity.
In the first part of the thesis, devoted to computer network monitoring. We take advantage
of the FPGA determinism in order to implement active monitoring probes, which
consist on sending a train of packets which is later used to obtain network parameters.
In this case, the determinism is key to reduce the uncertainty of the measurements.
The results of our experiments show that the FPGA implementations are much more
accurate and more precise than the software counterpart. At the same time, the FPGA
implementation is scalable in terms of network speed â 1, 10 and 100 Gbit/s. In the context of passive monitoring, we leverage the FPGA architecture to implement algorithms
able to thin cyphered traffic as well as removing duplicate packets. These two algorithms
straightforward in principle, but very useful to help traditional network analysis tools to
cope with their task at higher network speeds. On one hand, processing cyphered traffic
bring little benefits, on the other hand, processing duplicate traffic impacts negatively in
the performance of the software tools.
In the second part of the thesis, devoted to the TCP/IP stack. We explore the current
limitations of reliable data transmission using standard software at very high-speed.
Nowadays, the network is becoming an important bottleneck to fulfill current needs, in
particular in data centers. What is more, in recent years the deployment of 100 Gbit/s
network links has started. Consequently, there has been an increase scrutiny of how
networking functionality is deployed, furthermore, a wide range of approaches are
currently being explored to increase the efficiency of networks and tailor its functionality
to the actual needs of the application at hand. FPGAs arise as the perfect alternative to
deal with this problem. For this reason, in this thesis we develop Limago an FPGA-based
open-source implementation of a TCP/IP stack operating at 100 Gbit/s for Xilinxâs FPGAs.
Limago not only provides an unprecedented throughput, but also, provides a tiny latency
when compared to the software implementations, at least fifteen times. Limago is a key
contribution in some of the hottest topic at the moment, for instance, network-attached
FPGA and in-network data processing
Management, Optimization and Evolution of the LHCb Online Network
The LHCb experiment is one of the four large particle detectors running at the
Large Hadron Collider (LHC) at CERN. It is a forward single-arm spectrometer dedicated to test the Standard Model through precision measurements of
Charge-Parity (CP) violation and rare decays in the b quark sector. The LHCb
experiment will operate at a luminosity of 2x10^32cm-2s-1, the proton-proton
bunch crossings rate will be approximately 10 MHz. To select the interesting
events, a two-level trigger scheme is applied: the rst level trigger (L0) and the
high level trigger (HLT). The L0 trigger is implemented in custom hardware,
while HLT is implemented in software runs on the CPUs of the Event Filter
Farm (EFF). The L0 trigger rate is dened at about 1 MHz, and the event size
for each event is about 35 kByte. It is a serious challenge to handle the resulting
data rate (35 GByte/s).
The Online system is a key part of the LHCb experiment, providing all the
IT services. It consists of three major components: the Data Acquisition (DAQ)
system, the Timing and Fast Control (TFC) system and the Experiment Control
System (ECS). To provide the services, two large dedicated networks based on
Gigabit Ethernet are deployed: one for DAQ and another one for ECS, which are
referred to Online network in general. A large network needs sophisticated monitoring for its successful operation. Commercial network management systems are
quite expensive and dicult to integrate into the LHCb ECS. A custom network
monitoring system has been implemented based on a Supervisory Control And
Data Acquisition (SCADA) system called PVSS which is used by LHCb ECS. It
is a homogeneous part of the LHCb ECS. In this thesis, it is demonstrated how
a large scale network can be monitored and managed using tools originally made
for industrial supervisory control.
The thesis is organized as the follows:
Chapter 1 gives a brief introduction to LHC and the B physics on LHC,
then describes all sub-detectors and the trigger and DAQ system of LHCb from
structure to performance.
Chapter 2 first introduces the LHCb Online system and the dataflow, then
focuses on the Online network design and its optimization.
In Chapter 3, the SCADA system PVSS is introduced briefly,
then the
architecture and implementation of the network monitoring system are described
in detail, including the front-end processes, the data communication and the
supervisory layer.
Chapter 4 first discusses the packet sampling theory and one of the packet
sampling mechanisms: sFlow, then demonstrates the applications of sFlow for
the network trouble-shooting, the traffic monitoring and the anomaly detection.
In Chapter 5, the upgrade of LHC and LHCb is introduced, the possible
architecture of DAQ is discussed, and two candidate internetworking technologies (high speed Ethernet and InfniBand) are compared in different aspects for
DAQ. Three schemes based on 10 Gigabit Ethernet are presented and studied.
Chapter 6 is a general summary of the thesis
Ethernet - a survey on its fields of application
During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application fieldâs requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal
The ATLAS Data Acquisition and High Level Trigger system
This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.Facultad de Ciencias Exacta
The ATLAS Data Acquisition and High Level Trigger system
This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.Facultad de Ciencias Exacta
Facing the Reality: Validation of Energy Saving Mechanisms on a Testbed
Two energy saving approaches, called Fixed Upper Fixed Lower (FUFL) and Dynamic Upper Fixed Lower (DUFL), switching off idle optical Gigabit Ethernet (GbE) interfaces during low traffic periods, have been implemented on a testbed. We show on a simple network scenario that energy can be saved using off-the-shelf equipment not explicitly designed for dynamic on/off operation. No packet loss is experienced in our experiments. We indicate the need for faster access to routers in order to perform the reconfiguration. This is particularly important for the more sophisticated energy saving approaches such as DUFL, since FUFL can be implemented locally
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