Researches on green data centers have defined guidelines and end-to-end methodologies to increase energy efficiency. Most of these approaches require a disrupting reengineering of the infrastructure and significant upfront investments. Smaller data centers need to reach green objectives with a more incremental approach. The EnergIT project proposes a methodology and related tools that support t...

In this paper, we focus on the performance of TCP splitting in satellite-terrestrial hybrid networks. By simulation we show that long-time link outage has great negative impact on TCP throughput. To solve the problem, an ACK reservation scheme is proposed to speed up TCP recovery from link outage and analytical estimate of a key parameter of the scheme is provided for achieving high end-to-end ...

Significant economic and technical benefits accrue from the use of pre-existing and commercially available software components to develop new systems. However, challenges remain that, if not adequately addressed, will slow the adoption of software component technology. Chief among these are a lack of consumer trust in the quality of components, and a lack of trust in the quality of assemblies o...

There has been an increasing consensus in the video distribution industry that the design and operation of the full video delivery chain needs to be driven by the quality-of-experience (QoE) appropriate to the end-user. In practice, however, this is an extremely difficult task, largely due to the lack of effective mechanisms to instantaneously measure or predict every viewer's QoE. Moreover, ex...

The workload of a network is usually a heterogeneous aggregate of services and applications, driven by a large number of users. This complexity makes it challenging to evaluate the performance of network mechanisms and configurations under realistic conditions. We propose a new methodology for transforming anonymized traces of packet headers into application-neutral models of network traffic. T...

We previously proposeda new version of TCP, called Inline measurement TCP (ImTCP), in [2, 3]. The ImTCP sender adjusts the transmission intervals of data packets and then utilizes the arrival intervals of ACK packets for available bandwidth estimation. This type of active measurement is preferred because the obtained results are as accurate as those of other conventional types of active measure...

Traditional network abstractions follow a layered model in which a sub-system interacts with other network components through very narrow interfaces. We content that this model is weak both in providing clear models of end-to-end properties and allowing adaptation to the more abstract properties of systems. We propose instead a graphcentric, contextual abstract model in which sub-systems can re...

The increasingly common practice of (1) replicating datasets and (2) using resources as distributed data stores in Grid environments has lead to the problem of determining which replica can be accessed most efficiently. Due to diverse performance characteristics and load variations of several components in the end-to-end path linking these various locations, selecting a replica location from am...

We present SfSNet, an end-to-end learning framework for producing an accurate decomposition of an unconstrained human face image into shape, reflectance and illuminance. SfSNet is designed to reflect a physical lambertian rendering model. SfSNet learns from a mixture of labeled synthetic and unlabeled real world images. This allows the network to capture low frequency variations from synthetic ...

The TCP transport layer protocol is designed for connections that traverse a single path between the sender and receiver. However, there are several environments in which multiple paths can be used by a connection simultaneously. In this paper we consider the problem of supporting striped connections that operate over multiple paths. We propose an end-to-end transport layer protocol called pTCP...