A multidimensional control architecture for combined fog-to-cloud systems

The fog/edge computing concept has set the foundations for the deployment of new services leveraging resources deployed at the edge paving the way for an innovative collaborative model, where end-users may collaborate with service providers by sharing idle resources at the edge of the network. Combined Fog-to-Cloud (F2C) systems have been recently proposed as a control strategy for managing fog and cloud resources in a coordinated way, aimed at optimally allocating resources within the fog-to-cloud resources stack for an optimal service execution. In this work, we discuss the unfeasibility of the deployment of a single control topology able to optimally manage a plethora of edge devices in future networks, respecting established SLAs according to distinct service requirements and end-user profiles. Instead, a multidimensional architecture, where distinct control plane instances coexist, is then introduced. By means of distinct scenarios, we describe the benefits of the proposed architecture including how users may collaborate with the deployment of novel services by selectively sharing resources according to their profile, as well as how distinct service providers may benefit from shared resources reducing deployment costs. The novel architecture proposed in this paper opens several opportunities for research, which are presented and discussed at the final section.This work was supported by the H2020 EU mF2C project, ref. 730929 and for UPC authors, also by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under contract RTI2018-094532-B-I00.Peer ReviewedPostprint (author's final draft

Reducing the effects of routing inaccuracy by means of prediction and an innovative linkstate cost

Abstract-The routing inaccuracy problem is one of the major issues impeding the evolution and deployment of ConstraintBased Routing (CBR) techniques. This paper proposes a promising CBR strategy that combines the strengths of prediction with an innovative link-state cost. The latter explicitly integrates a two-bit counter predictor, with a novel metric that stands for the degree of inaccuracy (seen by the source node) of the state information associated with the links along a path. In our routing model, Link-State Advertisements (LSAs) are only distributed upon topological changes in the network, i.e., the state and availability of network resources along a path are predicted from the source rather than updated through conventional LSAs. As a proof-of-concept, we apply our routing strategy in the context of circuit-switched networks. We show that our approach considerably reduces the impact of routing inaccuracy on the blocking probability, while eliminating the typical LSAs caused by the traffic dynamics in CBR protocols

Performance of translucent optical networks under dynamic traffic and uncertain physical-layer information

This paper investigates the performance of translucent Optical Transport Networks (OTNs) under different traffic and knowledge conditions, varying from perfect knowledge to drifts and uncertainties in the physical-layer parameters. Our focus is on the regular operation of a translucent OTN, i.e., after the dimensioning and regenerator placement phase. Our contributions can be summarized as follows. Based on the computation of the Personick’s Q factor, we introduce a new methodology for the assessment of the optical signal quality along a path, and show its application on a realistic example. We analyze the performance of both deterministic and predictive RWA techniques integrating this signal quality factor Q in the lightpath computation process. Our results confirm the effectiveness of predictive techniques to deal with the typical drifts and uncertainties in the physical-layer parameters, in contrast to the superior efficacy of deterministic approaches in case of perfect knowledge. Conversely to most previous works, where all wavelengths are assumed to have the same characteristics, we examine the case when the network is not perfectly compensated, so the Maximum Transmission Distance (MTD) of the different wavelength channels may vary. We show that blocking might increase dramatically when the MTD of the different wavelength channels is overlooked.Postprint (published version

Securing combined Fog-to-Cloud systems: challenges and directions

Nowadays, fog computing is emerged for providing computational power closer to the users. Fog computing brings real-time processing, lowlatency, geo-distributed and etc. Although, fog computing do not come to compete cloud computing, it comes to collaborate. Recently, Fog-To-Cloud (F2C) continuum system is introduced to provide hierarchical computing system and facilitates fog-cloud collaboration. This F2C continuum system might encounter security issues and challenges due to their hierarchical and distributed nature. In this paper, we analyze attacks in different layer of F2C system and identify most potential security requirements and challenges for the F2C continuum system. Finally, we introduce the most remarkable efforts and trends for bringing secure F2C system.This work is supported by the H2020 projects mF2C (730929). It is also supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund both under contract RTI2018-094532-B-100.Peer ReviewedPostprint (author's final draft

Open issues in interdomain routing: A survey

This article surveys several research challenges in interdomain routing. We introduce and describe these challenges in a comprehensible manner, along with a review of the most compelling contributions and ongoing research efforts addressing each of the exposed issues. During this analysis we identify the relation between these research challenges and how they influence each other. We also present our perspectives on why these issues remain largely unsolved, and joint out why same of the proposals made so far have not yet been adopted. We hope this can provide some insight on future directions in this, complex research area

Reliable Routing with QoS Guarantees for Multi-Domain IP/MPLS Networks

We present a distributed routing algorithm for finding two disjoint (primary and backup) QoS paths that run across multiple domains. Our work is inspired by the recent interest in establishing communication paths with QoS constrains spanning multiple IP/MPLS domains. In such settings, the routing decisions in each domain are made by the Path Computation Element (PCE). We assume that the PCEs run a joint distributed routing protocol, decoupled from the BGP, which enables them to establish efficient paths across multiple domains. This study makes the following contributions. First, we present an aggregated representation of a multi-domain network that is small enough to minimize the link-state overhead, and, at the same time, is sufficiently accurate, so that the PCEs can find optimal disjoint QoS paths across multiple domains. Second, we present a distributed routing algorithm that uses the proposed representation to find disjoint paths in an efficient manner. Finally, we consider the problem of finding two disjoint paths subject to the export policy limitations, imposed by customer-provider and peer relationships between routing domains. We show that this problem can be efficiently solved by employing the concept of line graphs. To the best of our knowledge, this is the first scheme fully decoupled from BGP that enables to establish disjoint QoS IP/MPLS paths in a multi-domain environment with provable performance guarantees