1 Asynchronous vs Synchronous Input-Queued Switches

Abstract—Input-queued (IQ) switches are one of the reference architectures for the design of high-speed packet switches. Classical results in this field refer to the scenario in which the whole switch transfers the packets in a synchronous fashion, in phase with a sequence of fixedsize timeslots, tailored to transport a minimum-size packet. However, for switches with large number of ports and high bandwidth, maintaining an accurate global synchronization and transferring all the packets in a synchronous fashion is becoming more and more challenging. Furthermore, variable size packets (as in the traffic present in the Internet) require rather complex segmentation and reassembly processes and some switching capacity is wasted due to partial filling of timeslots. Thus, in this work we consider a switch able to natively transfer packets in an asynchronous fashion thanks to a simple and distributed packet scheduler. We investigate the performance of asynchronous IQ switches and show that, despite their simplicity, their performance is comparable or even better than those of synchronous switches. These results highlight the great potential of the asynchronous approach for the design of high-performance switches.

Research Article An Improved Particle Swarm Optimization Based on Deluge Approach for Enhanced Hierarchical Cache Optimization in IPTV Networks

Abstract: In recent years, IP network has been considered as a new delivery network for TV services. A majority of the telecommunication industries have used IP network to offer on-demand services and linear TV services as it can offer a two-way and high-speed communication. In order to effectively and economically utilize the IP network, caching is the technique which is usually preferred. In IPTV system, a managed network is utilized to bring out TV services, the requests of Video on Demand (VOD) objects are usually combined in a limited period intensively and user preferences are fluctuated dynamically. Furthermore, the VOD content updates often under the control of IPTV providers. In order to minimize this traffic and overall network cost, a segment of the video content is stored in caches closer to subscribers, for example, Digital Subscriber Line Access Multiplexer (DSLAM), a Central Office (CO) and Intermediate Office (IO). The major problem focused in this approach is to determine the optimal cache memory that should be assigned in order to attain maximum cost effectiveness. This approach uses an effective Grate Deluge algorithm based Particle Swarm Optimization (GDPSO) approach for attaining the optimal cache memory size which in turn minimizes the overall network cost. The analysis shows that hierarchical distributed caching can save significant network cost through the utilization of the GDPSO algorithm

Solución Cliente-Servidor para IPTV basada en VLC

La evolución de la televisión tradicional al formato IPTV se está produciendo a una gran velocidad, debido a los profundos cambios aparecidos tanto a nivel de sistemas y redes de comunicaciones como de dispositivos. Esta evolución provoca que los nuevos proveedores y suministradores de servicios de IPTV necesiten disponer de herramientas que permitan la gestión de sus contenidos. Este proyecto ha consistido en el desarrollo de una nueva herramienta, de nombre 'AC TV Manager', que sirve para la gestión de los canales, la continuidad televisiva y la posterior emisión vía streaming que debe proporcionar un servicio de IPTV. Se ha desarrollado en lenguaje Java y sirve como interfaz entre un usuario administrador, VLC y FFmpeg, pues uno de los objetivos es que la herramienta no sea propietariaThe switch from traditional television to Internet Protocol television (IPTV) is accelerating as a result of profound changes to devices, systems and communication networks. Due to this evolution, IPTV service suppliers and providers require tools to manage their contents. This project has inspired the development of new software called 'AC TV Manager' which manages the channels, televised continuity and posterior broadcast via streaming provided by an IPTV service. It has been developed in Java and is an interface between the admin user, VLC and FFmpeg, as one of its objectives is for the tool not to be proprietary software.Chas Arizcuren, A. (2015). Solución Cliente-Servidor para IPTV basada en VLC. Universitat Politècnica de València. http://hdl.handle.net/10251/54773TFG

Simulación y evaluación de una arquitectura IPTV de video en tiempo real, mediante software libre.

El objetivo de este proyecto fue evaluar las principales características en el servicio de contenidos de televisión y video por demanda, a través de la simulación de una arquitectura IPTV mediante software libre. Se identificaron los parámetros a nivel de red que afectan la QoS como: Delay, variación del retardo (jitter), pérdida de paquetes, ancho de banda, así como también el tipo de protocolo (RTSP y HTTP) utilizado para la transmisión del servicio, a nivel de usuario estos parámetros afectan en la visualización del video. Para la simulación se utilizó dos escenarios: el primero una red Multicasting con tecnología GPON, el segundo una red Multicasting con tecnología ADSL mediante el software libre Opnet Modeler que ahora se conoce como River Modeler, y el software GNS3. De los resultados obtenidos se tiene que la arquitectura IPTV Multicast con GPON es mucho más eficiente que una arquitectura IPTV Multicast con ADSL, ya que a más de ser un medio confiable y seguro brinda mayor velocidad de transmisión alcanzando los 1.2 Gbps en un enlace ascendente y los 2.4 Gbps en un enlace descendente, tiene un menor delay lo que indica que la visualización del contenido multimedia es más fluido y eficiente, permite una mayor cantidad de paquetes enviados y recibidos. Además, se puede concluir que el protocolo HTTP presentó un mejor desempeño en comparación a RSTP, ya que mostró menores perdidas y menor retardo.The objetive of this project was to evaluate the main features in the televisión and video content service on demand, through the simulation of an IPTV architecture through free sotware. We identified the parameters at the network level that affect the QoS such as: Delay, variation of the delay (jitter), packet loss, bandwidth, as well as the type of protocol (RTSP and HTTP) used for the transmisión of the service, at the user level, these parameters affect the video display. Fort he simulation, two scenarios were carried out: the first a Multicasting network with GPON technology, the second a Multicasting network with ADSL technology using the free software Opnet Modeler that is now known as River Modeler, and the GNS3 software. From the results obtained, the IPTV Multicast architecture with GPON is much more efficient than an IPTV Multicast architecture with ADSL, since besides being a reliable and secure means it provides a higher transmisión speed reaching 1.2 Gbps in an uplink and the 2.4 Gbps in a downlink, has a lower delay wich indicates that the visualization of multimedia content is more fluid and efficient, allows a greater number of packets sent and received. In addition, it can be concluded that the HTTP protocol presented a better performance in comparison to RSTP, since it showed lower losses and lower delay

Simulación y evaluación de una arquitectura IPTV de video en tiempo real, mediante software libre.

El objetivo de este proyecto fue evaluar las principales características en el servicio de contenidos de televisión y video por demanda, a través de la simulación de una arquitectura IPTV mediante software libre. Se identificaron los parámetros a nivel de red que afectan la QoS como: Delay, variación del retardo (jitter), pérdida de paquetes, ancho de banda, así como también el tipo de protocolo (RTSP y HTTP) utilizado para la transmisión del servicio, a nivel de usuario estos parámetros afectan en la visualización del video. Para la simulación se utilizó dos escenarios: el primero una red Multicasting con tecnología GPON, el segundo una red Multicasting con tecnología ADSL mediante el software libre Opnet Modeler que ahora se conoce como River Modeler, y el software GNS3. De los resultados obtenidos se tiene que la arquitectura IPTV Multicast con GPON es mucho más eficiente que una arquitectura IPTV Multicast con ADSL, ya que a más de ser un medio confiable y seguro brinda mayor velocidad de transmisión alcanzando los 1.2 Gbps en un enlace ascendente y los 2.4 Gbps en un enlace descendente, tiene un menor delay lo que indica que la visualización del contenido multimedia es más fluido y eficiente, permite una mayor cantidad de paquetes enviados y recibidos. Además, se puede concluir que el protocolo HTTP presentó un mejor desempeño en comparación a RSTP, ya que mostró menores perdidas y menor retardo.The objetive of this project was to evaluate the main features in the televisión and video content service on demand, through the simulation of an IPTV architecture through free sotware. We identified the parameters at the network level that affect the QoS such as: Delay, variation of the delay (jitter), packet loss, bandwidth, as well as the type of protocol (RTSP and HTTP) used for the transmisión of the service, at the user level, these parameters affect the video display. Fort he simulation, two scenarios were carried out: the first a Multicasting network with GPON technology, the second a Multicasting network with ADSL technology using the free software Opnet Modeler that is now known as River Modeler, and the GNS3 software. From the results obtained, the IPTV Multicast architecture with GPON is much more efficient than an IPTV Multicast architecture with ADSL, since besides being a reliable and secure means it provides a higher transmisión speed reaching 1.2 Gbps in an uplink and the 2.4 Gbps in a downlink, has a lower delay wich indicates that the visualization of multimedia content is more fluid and efficient, allows a greater number of packets sent and received. In addition, it can be concluded that the HTTP protocol presented a better performance in comparison to RSTP, since it showed lower losses and lower delay

Understanding the performance of Internet video over residential networks

Video streaming applications are now commonplace among home Internet users, who typically access the Internet using DSL or Cable technologies. However, the effect of these technologies on video performance, in terms of degradations in video quality, is not well understood. To enable continued deployment of applications with improved quality of experience for home users, it is essential to understand the nature of network impairments and develop means to overcome them. In this dissertation, I demonstrate the type of network conditions experienced by Internet video traffic, by presenting a new dataset of the packet level performance of real-time streaming to residential Internet users. Then, I use these packet level traces to evaluate the performance of commonly used models for packet loss simulation, and finding the models to be insufficient, present a new type of model that more accurately captures the loss behaviour. Finally, to demonstrate how a better understanding of the network can improve video quality in a real application scenario, I evaluate the performance of forward error correction schemes for Internet video using the measurements. I show that performance can be poor, devise a new metric to predict performance of error recovery from the characteristics of the input, and validate that the new packet loss model allows more realistic simulations. For the effective deployment of Internet video systems to users of residential access networks, a firm understanding of these networks is required. This dissertation provides insights into the packet level characteristics that can be expected from such networks, and techniques to realistically simulate their behaviour, promoting development of future video applications

Measurements of Multicast Television over IP

In this paper, we present measurement results collected from real traces on the network FastWeb, an ISP provider that is the main broadband telecommunication company in Italy. The network relies on a fully IP architecture and delivers to the user services such as data, VoIP and IP television over a single broadband connection. Our measurements, that are based on a passive measurement technique, focus on IP Television (IPTV) multicast, that consists of 83 digital TV channels encoded using different MPEG-2 encoders. The results show that, depending on the encoder and based on the bitrate, flows can be classified as being: CBR, 2-VBR (i.e., two typical bitrate values) and VBR. Measurement of the packet loss, jitter and inter-packet gap show that, independently from the class, packet generation process of the flows can have various degrees of burstiness. Despite the packet level burstiness, average jitter is limited to few milliseconds and no packet loss was ever observed, showing that the quality of IPTV offered by FastWeb is excellen

Measurements of Multicast Television over IP

Abstract — In this paper, we present measurement results collected from real traces on the network FastWeb, an ISP provider that is the main broadband telecommunication company in Italy. The network relies on a fully IP architecture and delivers to the user services such as data, VoIP and IP television over a single broadband connection. Our measurements, that are based on a passive measurement technique, focus on IP TeleVision (IPTV) multicast, that consists of 83 digital TV channels encoded using different MPEG-2 encoders. The results show that, depending on the encoder and based on the bitrate, flows can be classified as being: CBR, 2-VBR (i.e., two typical bitrate values) and VBR. Measurement of the packet loss, jitter and inter-packet gap show that, independently from the class, packet generation process of the flows can have various degrees of burstiness. Despite the packet level burstiness, average jitter is limited to few milliseconds and no packet loss was ever observed, showing that the quality of IPTV offered by FastWeb is excellent. I