Papers by Ivan Bernal Carrillo
Resumen MP-TCP (MultiPath-TCP) es un protocolo que permite el envío de datos por múltiples camino... more Resumen MP-TCP (MultiPath-TCP) es un protocolo que permite el envío de datos por múltiples caminos en dispositivos que poseen varias interfaces de red. Una conexión MP-TCP se divide en varias conexiones TCP denominadas subflujos, de esta manera se puede incrementarla tasa efectiva de la conexión y la resistencia a fallos. Sin embargo, en un escenario en el que se emplee MP-TCP con un cliente y un servidor, cada uno con una sola interfaz de red, se puede tener que los subflujos creados sigan el mismo camino a pesar que existan varios disponibles; esto genera el problema denominado cuello de botella compartido (shared bottleneck). El artículo describe el desarrollo del código en C++ para realizar la simulación del problema del shared bottleneck en el simulador de redes NS3. La simulación está desarrollada con la infraestructura DCE (Direct Code Execution) para NS3 de tal manera que se puede utilizar una implementación existente de MP-TCP instalada en un kernel de Linux. Con la implementación desarrollada se realizan pruebas y se presentan y discuten los resultados obtenidos, lo que permite complementar el estudio y análisis de este problema del que adolece MP-TCP. Entre los resultados se resalta la estimación de la tasa efectiva de transferencia que se obtiene variando el número de subflujos y caminos en escenarios en los que se presenta el problema del shared bottleneck.
Resumen-Los FPGAs actuales han sufrido cambios drásticos desde su aparición a mediados de la déca... more Resumen-Los FPGAs actuales han sufrido cambios drásticos desde su aparición a mediados de la década de los ochenta, de simples sistemas de lógica de acoplamiento a verdaderos sistemas en chip (SoC), con sistemas de millones de compuertas, capaces de albergar bloques lógicos que pueden implementar casi cualquier función lógica, así como bloques embebidos de microprocesadores, DSPs, e interfaces de entrada/salida de muy alta velocidad, haciendo que estos dispositivos sean aptos para casi cualquier aplicación. El presente trabajo pretende demostrar el potencial que poseen los FPGAs actuales y el lenguaje de descripción de hardware VHDL, para sintetizar a nivel de hardware algoritmos complejos, como lo es el esquema de codificación Baseline del estándar JPEG para la compresión de imágenes, mediante el uso de los estilos descriptivos que posee el lenguaje VHDL. Para ello se utiliza el módulo de desarrollo Spartan-3A Starter Kit Board, que posee un FPGA XC3S700A de la Familia Spartan-3A de Xilinx y la herramienta de desarrollo ISE Foundation 10.1. El sistema diseñado admite los datos de una imagen monocromática de 160x120 pixeles sin comprimir, y devuelve los datos de la imagen comprimida con el formato de archivo JFIF para imágenes. Además se emplea una interfaz gráfica de usuaria, desarrollada con el entorno de programación gráfica GUIDE de Matlab, para la interacción con el sistema diseñado y la visualización de resultados.
Este artículo presenta un plug-in para el Entorno de Desarrollo Integrado (IDE) NCL Composer, cap... more Este artículo presenta un plug-in para el Entorno de Desarrollo Integrado (IDE) NCL Composer, capaz de generar menús con varias características y funcionalidades personalizables. El plug-in brinda una interfaz gráfica amigable al usuario para diseñar menús y genera de forma automática el código en lenguaje NCL (Nested Context Language) de los menús diseñados. De esta manera, el usuario puede crear fácilmente aplicaciones interactivas basadas en Ginga-NCL para televisión digital, las cuales presenten al televidente menús con un alto nivel de interactividad, en menor tiempo de desarrollo y sin necesidad de tener conocimientos avanzados del lenguaje NCL. Como ejemplo, se presentan tres aplicaciones interactivas que fueron desarrolladas empleando el plug-in.
Revista de investigación en tecnologías de la información, Jun 1, 2017
Resumen MP-TCP (MultiPath-TCP) es un protocolo que permite el envío de datos por múltiples camino... more Resumen MP-TCP (MultiPath-TCP) es un protocolo que permite el envío de datos por múltiples caminos en dispositivos que poseen varias interfaces de red. Una conexión MP-TCP se divide en varias conexiones TCP denominadas subflujos, de esta manera se puede incrementarla tasa efectiva de la conexión y la resistencia a fallos. Sin embargo, en un escenario en el que se emplee MP-TCP con un cliente y un servidor, cada uno con una sola interfaz de red, se puede tener que los subflujos creados sigan el mismo camino a pesar que existan varios disponibles; esto genera el problema denominado cuello de botella compartido (shared bottleneck). El artículo describe el desarrollo del código en C++ para realizar la simulación del problema del shared bottleneck en el simulador de redes NS3. La simulación está desarrollada con la infraestructura DCE (Direct Code Execution) para NS3 de tal manera que se puede utilizar una implementación existente de MP-TCP instalada en un kernel de Linux. Con la implementación desarrollada se realizan pruebas y se presentan y discuten los resultados obtenidos, lo que permite complementar el estudio y análisis de este problema del que adolece MP-TCP. Entre los resultados se resalta la estimación de la tasa efectiva de transferencia que se obtiene variando el número de subflujos y caminos en escenarios en los que se presenta el problema del shared bottleneck.
Resumen-El desarrollo del middleware Globus Toolkit que integra tecnologías como los sistemas dis... more Resumen-El desarrollo del middleware Globus Toolkit que integra tecnologías como los sistemas distribuidos, el Internet, los servicios web, seguridad, la virtualización y las redes peer-to-peer ha permitido la conformación de Grids. Por otro lado, basándose en la tecnología de clusters, en Matlab se han desarrollado herramientas para computación distribuida como Matlab Parallel Computing Toolbox y Matlab Distributed Computing Server. Este artículo inicia con una visión general de la computación Grid y el uso del middleware Globus Toolkit (GT), el cual permite realizar la implementación de una infraestructura de mini-grid conformada por recursos heterogéneos y distribuidos en un ambiente de laboratorio. Entre los recursos heterogéneos, se emplean computadoras con Sistema Operativo Linux e integradas al mini-grid con los servicios que ofrece el GT4; por otra parte, un cluster construido en base a las herramientas de computación distribuida de Matlab en computadoras con Sistema Operativo Windows, se integra al mini-grid en base a un servicio web desarrollado en Java, cumpliendo con especificaciones de seguridad. Se recicla una aplicación de elementos finitos para el cálculo de la distribución de campo eléctrico en una guía de onda de longitud infinita y se la modifica en base a las herramientas de paralelización de Matlab para ser ejecutada en el cluster. El servicio web que invoca a la aplicación del cluster de Matlab es desplegado en Windows en el contenedor de Globus Toolkit para ser consumido en el mini-grid.
Las redes Banyan son un tipo de red de interconexion multi-etapa (MIN) usadas tanto en el area de... more Las redes Banyan son un tipo de red de interconexion multi-etapa (MIN) usadas tanto en el area de procesamiento paralelo, asi como en la arquitectura de switches y routers de alta velocidad. En este articulo se toma como caso de estudio una red de 8x8 implementada con elementos de conmutacion Banyan duales y se pretende observar como varia el desempeno de la red al incrementar el tamano de los buffers internos. Para esto se presenta un analisis matematico basado en procesos estocasticos de Poisson y Cadenas de Markov, se describe la red con el lenguaje de descripcion de hardware VHDL y se procede a su simulacion y sintesis de la red en un FPGA. Finalmente, se presentan y evaluan los resultados obtenidos, contrastando lo obtenido teoricamente con lo obtenido en la simulacion. Banyan networks are a class of Multistage Interconnection Networks (MINs) used in both parallel computing and fast packet switches and routers architectures. In this paper, an 8x8 Banyan network is selected as a...
This paper presents the implementation of a cloud that is used for instantiating virtual machines... more This paper presents the implementation of a cloud that is used for instantiating virtual machines with a set of tools typically used for configuring and simulating networks based on Software Defined Networking (SDN). In terms of infrastructure, a web application is developed and included in each instantiated virtual machine so that even a user with minimal knowledge about SDN can create simple networks to start experimenting with this new network architecture. Users interact with the web application through a web interface that allows to select a topology, numbers of hosts and switches and choose from a given set of SDN controllers (POX, RYU and Pyretic). Some results obtained with the cloud, web application and the created SDN are presented.
This document presents a prototype that uses Network Coding as a tool for the recovery of lost pa... more This document presents a prototype that uses Network Coding as a tool for the recovery of lost packets in a butterfly network which is implemented using Software Defined Networking (SDN). The system is based on Ryu as the SDN controller; modules were developed for setting up the rules of the switches that structure the butterfly network, one without network coding and another for using it. Two complementary applications were developed, one for performing the tasks associated to network coding that requires generating new packets and the other for performing the necessary tasks to recover lost packets. Finally, the results of several tests performed using the prototype are presented and discussed and conclusions are drawn.
Solving MP-TCP‘s Shared Bottlenecks Using a SDN with OpenDayLight as the Controller
MP-TCP (MultiPath-Transmission Control Protocol) was designed to use multiple interfaces in hosts... more MP-TCP (MultiPath-Transmission Control Protocol) was designed to use multiple interfaces in hosts; it uses several subflows (a set of regular TCP connections) to increase the performance compared to TCP. However, when a host has only one network interface but several subflows are created, they follow the same path to their destination generating bottlenecks and MP-TCP advantages are lost. This paper presents a solution to the shared-bottleneck problem using SDN (Software Defined Networking). A plugin for OpenDayLight is developed for implementing Dijkstra's Algorithm to find paths and assign them to new subflows avoiding bottlenecks. The solution supports concurrent MP-TCP connections. Results of tests obtained using the implemented plugin in several topologies are presented.
On programming an MP-TCP analyzer plugin using OpenDayLight Beryllium as the SDN controller
MP-TCP (MultiPath-TCP) is a protocol that sends data through multiple paths in hosts that have se... more MP-TCP (MultiPath-TCP) is a protocol that sends data through multiple paths in hosts that have several network interfaces by creating a set of TCP (Transmission Control Protocol) connections. We propose using the principles of SDN (Software Defined Networking) for monitoring and analyzing traffic in a network. For implementing a concrete tool based on this idea, the key principles of the proposed solution must first be fully understood so they are described along with the programming aspects of the development of a plugin for analyzing MP-TCP messages using OpenDayLight (ODL) Beryllium as the SDN controller. The ODL's architecture and services used in the plugin implementation are also presented. ODL services are used trough their available API for developing our plugin. The MP-TCP plugin must generate both proactive and reactive rules that should be installed in the network devices so that MP-TCP messages are sent to the controller for processing and displaying to the network administrator. Results of tests obtained with the Analyzer when using physical and virtual switches in a linear topology are presented.
Desarrollo de Aplicaciones Interactivas para TV Digital orientadas a formar a la Población en Desastres Naturales
Revista Politécnica, Jul 31, 2013
Resumen: Se presenta el diseno e implementacion de aplicaciones interactivas para TV digital empl... more Resumen: Se presenta el diseno e implementacion de aplicaciones interactivas para TV digital empleando la alternativa GINGA-NCL, contemplada en el estandar ISDB-Tb, orientadas a formar a la poblacion en lo referente a fenomenos naturales tales como erupciones volcanicas, sismos y tsunamis en el Ecuador. Para determinar el contenido de dichas aplicaciones se conto con el asesoramiento tecnico del Instituto Geofisico de la EPN (IG-EPN) y en cuanto a las medidas de prevencion con el asesoramiento de la Secretaria Nacional de Gestion de Riesgos (SNGR). Se desarrollo una aplicacion principal conformada por tres aplicaciones secundarias, estas brindan el servicio de informacion adecuada sobre cada uno de los fenomenos naturales planteados. Ademas, se mencionan los resultados de las pruebas de funcionalidad de las aplicaciones tanto a nivel de simulacion asi como empleando un STB (Set Top Box) y televisores, utilizando tambien un transmisor de corto alcance. Se resumen ademas los resultados de encuestas MOS (Mean Opinion Score) realizadas a un grupo de televidentes, con el objetivo de observar el grado de aceptacion de las aplicaciones y que permitieron mejorar las versiones originales de las aplicaciones. Abstract: This work presents the design and implementation of several interactive applications fordigital TV based on the GINGA-NCL alternative, part of the ISDB-Tb standard, targeting to instruct thepopulation regarding natural phenomena such as volcanic eruptions, earthquakes and tsunamis in Ecuador.In order to determine the correct content of these applications, it was required the technical advice of theInstituto Geofisico de la EPN (IG-EPN) and Secretaria Nacional de Gestion de Riesgos (SNGR) for theprevention terms. A main application was developed containing three secondary ones, the latter provides preciseinformation about each of the natural phenomena mentioned above. The results of the functionality testsimplemented are mentioned; the tests include some at simulation level and others using an STB (Set Top Box)and TV sets along with a short range transmitter. The results of MOS (Mean Opinion Score) surveys madeto several viewers are also summarized which were carried out in order to measure the acceptance level of theinteractive applications which in turn allowed to improve the initial versions of the applications.
Revista Politécnica, Mar 15, 2016
This article pretends to provide an easy-to-understand overview of the requirements and the techn... more This article pretends to provide an easy-to-understand overview of the requirements and the technologies envisioned to support 5G cellular systems. Some meaningful statistics regarding the way traffic behaved during the year 2015 and a forecast up to year 2020 are presented. This allows a better understanding of the requirements for 5G that are currently being outlined and the applications that will be enabled. Given the orientation of this paper, two general aspects have been considered: a) How to increase and reach the required capacity of 5G systems by combining more spectrum, more cells and enhancing spectral efficiency by dealing with interference; and, b) The main aspects of the overall architecture of 5G systems, including discussions of the access network, backhaul and core. For each case several technologies that are under enhancements and optimization and others that are just being researched and still are in their initial steps are introduced and discussed.
Virtualizing and Deploying a Solution to MP-TCP’s Shared Bottlenecks as a Network Function
Network functions virtualization (NFV) offers an alternative way to design, deploy, and manage ne... more Network functions virtualization (NFV) offers an alternative way to design, deploy, and manage networking services. This paper presents the implementation and deployment of a virtualized network function to solve MP-TCP’ shared bottlenecks problem. MP-TCP (MultiPath-TCP) is a protocol that allows hosts that have several interfaces to send data through multiple paths in the network. An MP-TCP connection is divided into several TCP connections called subflows that may follow different paths, in this way effective connection rates and resilience can be increased. However, in a scenario where MP-TCP is used with hosts having a single network interface, created subflows follow the same path even if several are available; this generates the problem known as a shared bottleneck. A solution to this problem is implemented as a SDN (Software Defined Networking) module that is integrated into OpenDayLight’s framework which is used as the SDN controller. This solution is then deployed as a NFV over a cloud infrastructure implemented with OpenStack over a high-end physical server. The deployment of the NFV is automated to a certain degree using Ansible, a DevOps tool. Finally, results of the tests of the SDN solution to MP-TCP’s shared bottlenecks and its operation as a NFV using a completely virtualized network are reported.
Building a Basic Hardware and Software Infrastructure for Developing Ginga-NCL Interactive Applications
Communications in computer and information science, 2016
This work describes the software and hardware components that were integrated to structure a test... more This work describes the software and hardware components that were integrated to structure a testbed for developing interactive applications for ISDB-Tb´s Ginga middleware. A basic structure of the testbed was outlined and later built incrementally. This paper focuses on the set of software tools that we developed which turned into the basis of systems and applications that were created. The testbed allows obtaining the code for the applications and their transmission for testing on actual hardware. The developed applications can be sorted out into four categories: natural hazards, environmental issues, higher education and the evaluation of telecommunications services. For sure the testbed has its limitations but it was setup under a limited budget.
A prototype for a honeynet based on SDN
This paper presents a prototype for a honeynet based on SDN. The prototype is structured by a Pyr... more This paper presents a prototype for a honeynet based on SDN. The prototype is structured by a Pyretic controller, an application, a switch with OpenFlow support and a network. The network is composed of two segments; one of them called the production network, and the other, the honeynet. The application helps detecting and deviating attacks to the honeynet. Six different types of attacks are considered, three of them are Denial of Service (DoS) attacks and the other two are spoofing attacks. The DoS selected attacks are SMURF, THC SSL DoS and TCP SYN Flood; and the spoofing attacks are based on DNS, IP and ARP. The application contains a main module that is responsible for calling six additional modules, each designed for detecting a particular attack; the main module also loads a secondary module that injects the analyzed packets back into one of the two segments of the network. The application can be customized using a configuration file that flags whether the application will run a specific module or the six modules simultaneously; this allows protecting the network from either a particular attack or from all the six chosen attacks. A description of the developed modules using Pyretic is included. In addition, results of several tests carried out using the prototype for testing attacks are presented.
An efficient residential LTE small cell using a “designated” wireless local loop band
2017 IEEE Second Ecuador Technical Chapters Meeting (ETCM), 2017
Mobile Network Operators (MNOs) as well as Fixed Network Operators (FNOs) are actively searching ... more Mobile Network Operators (MNOs) as well as Fixed Network Operators (FNOs) are actively searching for solutions to satisfy the exponentially growing users' demand for broadband services, such as high definition video content and real time applications, at a reasonable CAPEX investment. At the same time, MNOs have to deal with the scarcity and expensiveness of the new “licensed” radio bands, and FNOs have to deal with the high congestion of the current “unlicensed” radio bands such as the Industrial, Scientific and Medical (ISM) radio band. However, some of the Wireless Local Loop (WLL) radio bands, such as the DECT band (1880/1900 MHz), due to their “designated” band status, attributed by the competent regulator entities, are much less congested. In this paper, we propose to re-engineer the Customer Premises Equipment (CPE) that FNOs provide to the end user, so that it continues to offer the traditional short-range Cordless Telephony service to a few DECT handsets but at the same...
Aplicación para Control de Acceso a la Red para SDN
Resumen: Las Redes Definidas por Software definen una nueva alternativa de arquitectura de red. E... more Resumen: Las Redes Definidas por Software definen una nueva alternativa de arquitectura de red. Esta alternativa esta basada en un modelo logico centralizado, cuya idea principal es que un programa o aplicacion pueda tomar decisiones para reenviar los paquetes a los switches, permitiendo un control granular del trafico de red. En este articulo se presenta un prototipo de SDN basado en software, el cual esta conformado por switches virtuales, un controlador y PC clientes; adicionalmente se presenta una aplicacion para NAC (Network Access Control), la cual se implementa en el controlador y permite controlar el acceso de los dispositivos a la red. Abstract: Software Defined Networks establish a new network architecture alternative. This alternative is based on a centralized logic model, which main idea is that a program or application can make decisions to forward packets to switches, allowing granular control of network traffic. This paper presents a SDN prototype based on software, w...
MP-TCP (MultiPath-Transmission Control Protocol) is a network protocol that uses subflows for all... more MP-TCP (MultiPath-Transmission Control Protocol) is a network protocol that uses subflows for allowing the existence of disjoint paths and increases the overall throughput with respect to employing a common TCP connection. The idea of analyzing MP-TCP messages using the principles of SDN (Software Defined Networking) is proposed. Relevant aspects of how the Analyzer was developed as a module for OpenDayLight’s SDN framework are presented. The Analyzer runs in the SDN controller and it commands the installation of appropriate rules in the network devices (switches supporting Openflow) so that all TCP traffic be derived to the controller. Then the Analyzer must identify MP-TCP messages by checking the options field of TCP and present all the related information to the user employing a GUI (Graphical User Interface). By combining the usage of proactive and reactive rules, the Analyzer’s implementation tries to minimize the impact of sending TCP traffic to the controller. The Analyzer h...
Cloud-Based Network Function Virtualization Using OPNFV Components
Proceedings of the 19th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Prospective and trends in technology and skills for sustainable social development” “Leveraging emerging technologies to construct the future”, 2021
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Papers by Ivan Bernal Carrillo