Luca Rea

On the Impact of Operative Systems Choice in End-User Bandwidth Evaluation: Testing and Analysis in a Metro-Access Network

In this work, we apply an accredited standard technique for end-user bandwidth evaluation in an ADSL access scenario and show that the choice of operating system has a critical impact on performances. In particular, our end-to-end File Transfer Protocol (FTP)-based bandwidth measurements point out the strong impact of TCP (Transmission Control Protocol) implementation. As a consequence, a testing scenario needs to be described not only according to the physical parameters, but also paying attention to software implementation factors that could affect the testing results.

Comparison between objective and subjective measurements of quality of service over an Optical Wide Area network

The introduction of intelligence for management and control of the quality of service (QoS) are key issues for the evolution of the next generation IP optical network based on Ethernet technology. A test bed of a core-access network was implemented to investigate such issues and in this paper, the authors report measurements concerning the QoS of multimedia services for different traffic conditions. The network was implemented with a differentiated service over Multi-Protocol Label Switch (MPLS) architecture; it consists of a real optical network based on core routers with optical Gigabit Ethernet (GBE) interfaces connected by means of long single mode fibres (about 50\,km), contained in an installed cable between Rome and Pomezia. The network is based on different access devices, but in this paper we only refer to an access based on Fibre To The building (FTTB) architecture. The QoS was investigated both in terms of network (or objective) tests that include packet loss, jitter, one way delay and throughput measurements and perceptive (or subjective) tests that conversely are based on the evaluation of user perception. The services under test mainly consisted of video streams that circulated in the network according to the switching operations based in the IP differentiated service over MPLS technique that allowed us to guarantee the QoS for some class of service, also in the presence of network overload. Particular attention was given to the correlation between objective and subjective measurements. Furthermore, in order to have a complete analysis about QoS of real networks, measurements were performed also in the presence of restoration operations for link failures; in particular we compare the results in the case of conventional IP network restoration with a procedure proposed by us and based on a link switching activated by the loss of signal command coming from the routers. Copyright

Experimental investigation on optical gigabit Ethernet network reliability for high-definition IPTV services

We show an experimental investigation about the quality of service of high-definition IPTV applications in a core-access gigabit Ethernet-multiprotocol label switching (MPLS) network test bed in terms of objective (or network) and subjective (or perceptive) measurements, using different network configurations. In the core part we investigated the role of the classes of services defined according to the differentiated service over MPLS and to the virtual private LAN service approach. Furthermore we also investigated the role of the restoration consequent to a link failure. For the access part we will show that for the asymmetric digital subscriber line 2+ (ADSL2+) architecture an important role is given to the edge routers to select the traffic with higher priority. Furthermore we show how an upgrade of the passive optical networks, by means of the WDM technique, can be particularly suitable for future peer-to-peer huge bandwidth services.

Quality of Service Control Based on Virtual Private Network Services in a Wide Area Gigabit Ethernet Optical Test Bed

Abstract We report an experimental investigation about the Virtual Private LAN Service technique to guarantee the quality of service in the metro/core network and also in the presence of access bandwidth bottleneck. We also show how the virtual private network can be set up for answering to a user request in a very fast way. The tests were performed in a GMPLS test bed with GbE core routers linked with long (tens of kilometers) GbE G.652 fiber links.

Quality of Service Measurements over an Optical GMPLS Wide Area Access Network

The introduction of intelligence for management and control of optical networks based on internet protocol and the quality of service (QoS) are key issues for the evolution of the next generation network. In this paper the authors report experimental results on QoS measurements related to different real time multimedia services in an optical network based on a ring configuration obtained by means of the fibers contained in an installed cable between Rome and Pomezia, core routers with optical Gigabit Ethernet interfaces and configured with differentiated service over multi-protocol label switching architecture.

Quality of Service Investigation on High Definition IPTV Services in a Multivendor Optical Network with ADSL Access

We report an experimental investigation about the Quality of Service of High Definition IPTV applications in a core-access network based on a DiffServ over MPLS architecture with GBE interfaces. We show that particular traffic treatments are required in the network, especially at the edge segment in order to guarantee high QoS performance.

Fast Restoration Based on Alternative Wavelength Paths in a Wide Area Optical IP Network

Abstract In this article we describe an experimental investigation of IP network restoration based on wavelength recovery. We propose a procedure for metro and wide area gigabit Ethernet networks that allows us to route the wavelength in case of link failure to another existing link by exploiting wavelength division multiplexing in the fiber. Such a procedure is obtained by means of an optical switch that is managed by a loss-of-light signal that is generated by a router in case of link failure. Such a method has been tested in an IP network consisting of three core routers with optical gigabit Ethernet interfaces connected by means of 50-km-long single-mode fibers between Rome and Pomezia. Compared with other conventional restoration techniques, such as OSPF and MPLS, our method -in very fast (20 ms) and is compatible with real-time TV services and low-cost chips.

Dynamic QoS control based on VPLS in service oriented transport networks

The virtual private line service (VPLS) represents an attractive solution for enterprise customers requiring ldquotransparent LAN servicerdquo among remote sites and across a MPLS core network. In this context, the QoS enforcement is a challenge due to the high expectation of customers that require the same guarantees as a private network. This paper describes the implementation of a dynamic QoS control in VPLS scenario realized using a service-oriented network architecture for MPLS transport network, named SOON (service oriented optical network). A SOON prototype has been realized on a real metro-access testbed to experimentally validate the dynamic and self-consistent configuration of QoS-enabled VPLS and to verify QoS performances for different level of services in case of traffic congestion.

Research on Optical Core Networks in the e-Photon/ONe Network of Excellence

This papers reports the advances in optical core networks research coordinated in the framework of the e- photon/ONe and e-photon/ONe+ networks of excellence.

Wireless M2M capacity analysis for smart distribution grids

In the recent years, advanced control techniques for power grid distribution have been provided in order to define a new concept of power grid management: the Smart Grid. Among of them, the use of Machine-to-Machine (M2M) will permit to define advanced monitoring system for the distribution grid. However, the unique characteristics of M2M communications pose a number of interesting challenges to the conventional telecommunications networks. In this paper, we analyzed the 4G cellular technology, the Long Term Evolution (LTE), to investigate if it could be a suitable technology for the local loop solution. The analysis in terms of coverage and capacity is provided taking into account two exemplary case studies: AMI (Advanced Metering Infrastructure) and Distribution Substation Monitoring. The aim of this work is to check whether wireless access method of cellular technology is able to satisfy the proposed applications requirements.