Network slicing has been a key supporting technology for resource management in modern computer networks, from 5G to 6G and beyond. Network slicing creates virtual networks over one common physical infrastructure. The dynamic resource allocation for services and slices to serve demand variations caused by user mobility is a challenge in 5G networks. Based on the described scenario, this thesis developed new resource management mechanisms for the dynamic network slicing allocation problem to support mobile users in 5G/edge computing infrastructures. The contributions of this work include: 1) one evaluation of the performance of dynamic network slicing in user mobility support scenarios; 2) a mathematical model which describes the network slices reconfiguration delays; 3) two heuristic solutions for improving the network slice reconfiguration process; and 4) a network simulator for evaluating the proposed solutions. The simulator is available as free software and has been adopted as the validation environment by the scientific community. The results of this work indicate the positive impact of slices' dynamic resource allocation in dealing with demand variations triggered by mobile users. However, the frequency of those reconfigurations is crucial to the success of such a solution.

In contemporary urban environments, route recommendation systems have become an indispensable tool in moving the population from large centers, serving as valuable resources for circumventing traffic congestion. Enhancing vehicular traffic flow through strategic route adjustments is a pivotal element in improving traffic mobility. However, depending exclusively on traffic-related data for route recommendations fails to meet the essential criteria for ensuring effective management and safety for drivers and passengers during travel. Thus, context awareness and traffic data are crucial for enhancing efficiency and safety in traffic management. Our study proposes a two-context-aware approach to recommend safe routes for urban traffic management, considering road safety and travel time. Experiments were carried out using the widely recognized tool — HERE Navigation. Comparatively, our approach signifies a progressive stride in balancing mobility and security when contrasted with a single focus on travel time.

One key challenge in Adaptive Video Streaming is the ever-changing edge network conditions at the last mile of access networks. The edge environment is particularly dynamic, influenced by user locations, fluctuation in resource demands and resource capabilities, in contrast to traditional Content Delivery Network (CDN) setups, where content routing decisions are relatively known. To address the dynamism of edge computing environments and to enable applications to better exploit edge-cloud computing resources, this article focuses on content steering technology, a recent addition to adaptive video protocols such as HLS and DASH. We present AVENUE as an architecture for Content Steering Services to orchestrate video delivery dynamically across the Edge-Cloud Continuum. This work designs the principles of the Content Steering Service to create a mechanism that involves two modules - monitoring and selector: The monitoring module captures real-time context metrics, and the selector module chooses an edge server according to the Select Server Algorithm. Our study addresses three steering algorithms with different performance profiles. Numerical results demonstrate that different configurations may yield varying network performance in terms of Quality of Experience (QoE), cache hits, and request load. Moreover, the appropriate selection of heuristics in the Selector module can also have a significant impact, depending on the metric being evaluated.

Internet access is crucial to the human society as a platform for several services to the users. Despite this importance, the Internet suffers limitations that compromise Quality of Service (QoS) guarantees. Thus, Internet Service Providers (ISPs) need to evolve, adding new technologies and management strategies to their infrastructure. A promising approach is the slicing of network resources among clients and delivered services, where reliability and elastic resource demand through the day are key issues. Within this context, this paper presents an algorithm called Reliable Reuse Encourage (R-REENC), which defines network slices based on bandwidth requirements and the desired reliability for the clients. The results suggest that the proposed algorithm allocates more suitable slices than other existing approaches.

Due to the rapid increase of IoT applications and their use in many different areas, large amounts of data have been generated to be processed and stored. In this scenario, some applications are sensitive to high latency and response times. In order to fulfil these requirements, Edge and Fog Computing appear with the objective of bringing processing and storage devices closer to applications and management mechanisms. In this context, due to limitations related to high cost, scalability and planning, several mechanisms and algorithms need to be simulated before being implemented in the real world. This paper presents a comparison between two simulation tools and their main characteristics (EdgeCloudSim and iFogSim) using a smart campus scenario deployed at the University of Campinas, where the sensors collect data from water meters and smart energy marker watches, in addition to smart public transportation and battery disposal bins. Our evaluation shows that the information processing in edge and fog can efficiently serve the applications, however, each simulation tool has its specificities, and should be used according to the researcher's objectives and needs.

Multi-stream transport protocols, such as SCTP and QUIC, tackle challenges such as Head of Line (HoL) faced by TCP. They are getting more and more deployed and currently carry more than 7% of the global Internet traffic. However, since these protocols have limited control over the actual routes the streams will take in the network, the streams are generally forwarded through a single and same path, even though there are generally multiple paths available in the network. Consequently, the traffic streams do not fully benefit from the available bandwidth and performance improvement remains limited. Software Defined Networks (SDN) separate control planes and data planes. It offers a complete view of the network to applications and enables network programmability through flexible rules. These rules may be used to ensure that the different streams generated by multi-stream transport protocols follow multiple paths in the network. In this paper, we propose an SDN-based framework for multi-stream transport protocols in multipath networks. The proposed framework provides an interface for applications to specify multi-stream rules. Based on these rules, the framework uses the services offered by the SDN Controller to ensure that the multiple streams go over multiple paths in the network. Experiments performed show that our proposal improves the QoS offered to the end users.

Nowadays an increase in web services is noticed. The monitoring is essential to guarantee the quality of services. Monitoring is the basis for verifying violations but can also be used to predict a possible violation. This paper proposes a mechanism for load balancing in the web services provider. The monitor uses fuzzy techniques to predict a non-functional failure and acts not to allow that it happens. This failure may occur due to overhead on the provider. Results show an improvement in the accomplishment of e-contracts and a decrease in response times average. Comparing the fuzzy scheduling with other schedules is observed an improvement of up to 83.02% in the e-contracts accomplishment and a decrease of up to 96.21% in response times average. Also, using the fuzzy system, the provider overload was better balanced varying by a maximum of 12.04%, while for the other schedules the variation reached 68.99%. Analyzing the influence of the quantity of services on the provider, with the increase of the load, the fuzzy mechanism achieved a performance up to 61.67% higher. The results show that the mechanism proposed in this paper is promising to assist in load balancing on the provider.

In hybrid clouds, inter-cloud links play a key role in the execution of jobs with data dependencies. Insufficient available bandwidth in inter-cloud links can increase the makespan and the monetary cost to execute the application on public clouds. Imprecise information about the available bandwidth can lead to inefficient scheduling decisions. This paper attempts to evaluate the impact of imprecise information about the available bandwidth in inter-cloud links on workflow schedules, and it proposes a mechanism to cope with imprecise information about the available bandwidth and its impact on the makespan and cost estimates. The proposed mechanism applies a deflating factor on the available bandwidth value furnished as input to the scheduler. Simulation results showed that the mechanism is able to increase the number of solutions with makespans that are shorter than the defined deadline and reduce the underestimations of the makespan and cost provided by workflow schedulers.

The constant sharing of information among vehicles is of vital importance to provide different types of service in Intelligent Transportation Systems (ITS). Typically, ITS apply the sharing benefit to carrying out tasks such as extracting knowledge of vehicle traffic conditions and its distribution. The ITS that use this approach are able to perform the knowledge distribution, however, they lack of mechanisms to select the most appropriate vehicles to do so. It is common, in these systems, such tasks are performed by all vehicles. Consequently, it could easily cause a network overhead because of the highly redundant knowledge about the traffic that is being transmitted. With this in mind, we propose a system for information management and knowledge distribution named TRUSTed. The proposed system applies the egocentric betweenness measure to select the most relevant vehicle to carry out such tasks. Simulation results have shown that TRUSTed outperforms other systems found in the literature in several requirements.

The Internet became the primary medium for content sharing, playing a central role in our modern lives. This new paradigm changed the behavior of the user and the characteristics of the applications, such as multimedia content, real time interaction, among others. Thus, the Internet Service Providers (ISPs) need to evolve, adding new technologies and management strategies to their network infrastructures, resulting in the Future Internet Service Providers (FISPs). Within this context, this paper presents the key technical trends and challenges for the management of FISPs, considering the requirements of user's applications and the technologies to be standardized. Additionally, we introduce an architectural framework, called Framework for Integrated Management of Future Internet Service Providers (FIM), to expand the key technologies and to address the challenges in both access and edge networks, and to integrate the management of the FISP. A case study is presented to show the suitability of the proposed framework to enhance the management capacity of FISPs.

Nowadays, the Internet is part of our lives, as an essential way of communication and information. However, it suffers from limitations that prevent guarantees of Quality of Service (QoS) to the users. Thus, Internet Service Providers (ISPs) need to evolve, adding new technologies and management strategies, such as Network Virtualization (NV), Software Defined Network (SDN) and Network Function Virtualization (NFV), resulting in the Future Internet Service Providers (FISPs). FISPs slice their network resources among clients and delivered services, where an algorithm to define the structure of each slice is crucial to support Quality of Service (QoS) and resource utilization. Therefore, FISPs should consider the elastic resource utilization of the clients within periods of time through the day. In this context, this paper presents the Per Time Calculation (PETIC) algorithm to define slices based on the daytime bandwidth requirements of the clients. Numerical results suggest that the proposed algorithm defines more suitable slices than existing approaches.

Fog computing provides a low latency access to resources at the edge of the network for resource-constrained devices. The high mobility of some of these devices, such as vehicles, brings great challenges related to resource allocation and management. In order to improve the management of computing resources utilized by mobile users connected to the Fog infrastructure, this paper proposes a virtual machine placement and migration decision model based on mobility prediction. Simulations have shown that moving the virtual machine to a Fog node ahead of the user's route using the proposed approach can decrease by almost 50% the number of migrations needed by the user. The Fog architecture provides an average latency of about 15 milliseconds for the users' applications and the proposed approach presents a lower latency compared to a greedy approach for the VM placement problem.

The deployment of home automation projects is a simple task for IT professionals, but its a complex task for endusers to use the Internet of Things (IoT) technology. Moreover, the customization of the behavior of IoT devices is hard, since no friendly environment exists. Within this context, this paper presents a descriptive language to enable the programmability of IoT devices functionalities without changing their source code. The language allows the interaction between the end-user and IoT devices in a seamless friendly manner. Additionally, an architecture was designed to support this interaction between users and IoT devices. From a real IoT testbed, the proposed language and the designed architecture were evaluated, where both met the expected goals with a suitable performance.

Upcoming 5G mobile systems are expected to meet the QoS requirements of a massive amount of devices with different service constraints. In this context, 5G networks can not rely on the monolithic architecture present in today's networks. 5G mobile systems intend using network slicing to enable the creation of multiple logical networks (network slices) on top of a common physical infrastructure. These network slices are tailored according to the users' service requirements. Network slicing can be deployed due to the consolidation of multiple technologies, such as NFV and SDN. This paper introduces a component named Slice Optimizer, implemented as an extension of LTE's evolved NodeB, responsible to realize network slicing for LTE uplink transmission. The Slice Optimizer receives network slicing information from an Orchestrator, which is embedded in an SDN Controller. The Slice Optimizer, based on these network slicing information and on the current network state, selects the best slice to be scheduled at the moment. We performed extensive simulations to evaluate our proposal. The results show that our proposal can adapt to the network state, significantly increasing the user's QoS experience.

Ethernet is the main choice of connectivity in data centers operating in clouds. The Ethernet standards body (IEEE 802.3) has generated Ethernet specifications with increasing transmission rates since its inception. As a result, it is observed that data centers with groups of physical hosts having heterogeneous bandwidths. In this paper, we present an energy-aware virtual machine's scheduling method, taking into account this heterogeneity while aiming at energy efficiency. This method consists of two algorithms: one to determine to which physical hosts virtual machines should be allocated, and the other for the provision of bandwidth on physical hosts to virtual machines. Our study shows that, regarding energy savings for the studied scenarios, the presented method is comparable to other energy-aware methods in data centers with groups of machines with homogeneous settings, surpassing them in groups of machines with heterogeneous configurations, bringing improvements especially to data centers with heterogeneous bandwidths' networks or to where restrictive SLAs are used for the provision of bandwidth to virtual machines.

Imprecise input data imposes special challenges to workflow scheduling. This paper introduces a robust scheduler based on particle swarm optimisation, called RobWE, which considers uncertainties of available bandwidth when producing schedules for workflow ensembles. The proposed scheduler is also a flexible scheduler since it allows the replacement of its objective function according to the user's needs. The effectiveness of the proposed RobWE scheduler is compared to a non-robust scheduler that does not consider the presence of such uncertainties. Results of simulations considering diverse scenarios, based on several degrees of uncertainty in available bandwidth estimates, characteristics of bandwidth estimations and workflow applications, demonstrate the advantages of the proposed RobWE scheduler.

Software Defined Networking (SDN) and Network Function Virtualization (NFV) paradigms have been widely used to redesign the traditional mobile networks. Despite several proposals on the literature, researchers have drawn limited attention to the virtualization of user-plane functions that demand high traffic volume processing, as the case of Long Term Evolution (LTE) mobile gateways. This paper introduces an adaptive mechanism for the user plane virtualization of the LTE Packet Data Network (PDN) GateWay (P-GW), running entirely on top of OpenFlow switches. Using both SDN and NFV concepts, the proposed mechanism employs elastic computing notions to dynamically activate or deactivate the infrastructure switches so the virtualized gateway can adjust to workload changes. This work addresses both software and hardware OpenFlow infrastructure platforms, and simulation results highlight the benefits that can be achieved by the presented mechanism.

Urban mobility becomes one of the most challenging issues in large urban centers, since traffic congestion is a daily problem. In order to address this issue, a number of researchers, from both academia and industry, have studied several Traffic Management Systems (TMS) approaches to improve urban mobility. However, the existing approaches do not consider an essential factor: the population information. Within this context, this work proposes a new approach, called APOLO, that employs historical knowledge of mobility patterns of the drivers to obtain a global view of the road network. APOLO is different from others research approaches that need constant information exchange among the vehicles and the central server in order to obtain a global view of road traffic condition. These existing approaches can lead to network overload and have a high data processing cost in real-time. Results show that APOLO improves vehicles' mobility compared to well-known approaches, which indicates that APOLO could be a potential alternative for providing TMS services with valuable mobility knowledge.

It is our great pleasure to welcome you to the 15th IFIP/IEEE International Symposium on Integrated Network Management (IM 2017), sponsored by the IEEE Communications Society and IFIP Working Group 6.6. Held in odd-numbered years since 1989, IM 2017 will follow the 28-year tradition of IM as the primary IEEE Communications Society's forum for technical exchange on management of information and communication technology focusing on research, development, integration, standards, services, and user communities. IM 2017 focuses on the theme “Integrated Management in the Cloud and 5G Era”, that aims at capturing the emerging approaches and technical solutions for dealing with 5G and cloud infrastructures, as well as associated services and applications.

This paper presents the contributions of the phd thesis “Mechanisms for management of SLA for Virtual Software Defined Networks based on QoS Classes”. Over the years the Internet has become the primary means of communication, where the users expect to access the Internet anytime, anywhere, and with a certain quality level. As a consequence, in the past few years the traffic demand to Internet access has increased. However, since the current Internet does not guarantee Quality of Service (QoS) and Quality of Experience (QoE), the companies apply a Service Level Agreements (SLA) with Internet Service Providers (ISPs). In this way, the Internet service providers aim to improve utilization of network resources and service delivery to the users through the deployment of Virtual Networks (VNs) over Software Defined Networks (SDNs), called virtual software defined networks (VSDNs). However, the management of this type of environment still presents open issues. In this context, a set of mechanisms to manage VSDN was developed. The objectives of the developed mechanisms are to negotiate, to deploy and to adapt the VSDNs according to the current state of the network infrastructure and the SLA definition.

Ego-network concept has been systematically studied, since this kind of network employs only locally available information to analyze its structure. Degree, closeness, and betweenness are widely studied centrality measures. Among the three measures presented, betweenness centrality in ego-networks is the most used in several fields such as Wireless Mesh Networks, Wireless Sensor Networks, and Delay Tolerant Networks. However, surprisingly, that measure has not been largely investigated in Vehicular ad hoc Networks (VANETs). In this paper, we contribute to filling this gap by designing and implementing the egocentric betweenness measure in VANETs, besides we compare it to the sociocentric betweenness measure.

Understanding traffic conditions, in an urban environment, by means monitoring or/and predicting is not an easy task. In Intelligent Transportation Systems, the reliable vehicle route prediction has meaningful application value. Vehicle route prediction can increase the variety of VANETs applications such as predicting traffic situation ahead, optimal route recommendation, driver assistant, and automatic vehicle behaviors. Due to the challenge imposed by the vehicle route prediction and its wide application, researchers in both industry and academia have focused their efforts on this area. In order to explore this area, this paper describes an approach to predict the vehicle's future path in a realistic urban scenario. For that, it employs a hidden Markov model along with the outcome of the Viterbi algorithm to make a probabilistic prediction. The parameters modeling is estimated based on information extracted from the travel route dataset and computed in an offline manner. In the online phase, the routes prediction is carried out. Our approach has high accuracy rate according to the numerical simulations results. Moreover, we believe that the VANETs applications previously mentioned can take advantage of our approach.

Even after decades, the Internet does not provide Quality of Service (QoS) guarantee for the users. In order to soften such situation, clients negotiate Service Level Agreements (SLAs) with their Internet Service Providers (ISPs), where reliability and available bandwidth are key requirements for Internet services. On the other hand, the ISPs aim to decrease the energy consumption to deliver their services and provide a green environment. The mixing of Software Defined Networks (SDNs) and Virtual Networks (VNs), called Virtual Software Defined Network (VSDN), arises as a realizable option to deal with both client and provider perspectives. Within this context, this paper proposes two algorithms to allocate VSDNs combining reliability, bandwidth, and energy efficiency, considering the current network state to adjust the importance of each of these aspects during the allocation process. The results show the effectiveness of the proposed algorithms in allocating reliable VSDNs, while improving the energy efficiency and bandwidth usage of the ISP.

The growing data traffic demand is forcing network operators to deploy more base stations, culminating in dense heterogeneous networks that require a high-connectivity backhaul. This scenario imposes significant challenges for current and future cellular networks, and Software Defined Networking (SDN) has been pointed as an enabling technology to overcome existing limitations. This paper shows how the OpenFlow protocol can be integrated into existing Long Term Evolution (LTE) networks to provide the required Quality of Service (QoS) in the network infrastructure. Three OpenFlow-based mechanisms are proposed: a traffic routing, an admission control function, and a traffic coexistence mechanism. Together, they can effectively control the bandwidth usage in the backhaul infrastructure, improving the QoS and ensuring a better user experience. Simulations were performed to validate the proposed mechanisms and highlight the benefits that can be achieved with the flexibility offered by the SDN technology.

It is a consensus that the Internet suffers from architectural limitations, including resilience, scalability, and manageability, among others. Therefore, companies access the Internet by establishing a service level agreement (SLA) in the attempt to ensure quality of service (QoS) for users. To address the current limitations of the Internet, researchers have recently proposed the edge as a service (EaaS) paradigm as a suitable solution to improve the access capacity of edge networks. EaaS uses network virtualization and software-defined networks to expand flexibility and manageability of access to edge network resources. Moreover, to maintain QoS assurance for users, EaaS addresses network events (such as traffic overload, failures, etc.) that can potentially affect QoS. Within this context, this paper proposes a software-defined management of EaaS environment, called SDM-EaaS. The proposal enhances the QoS for the end user, while improving the utilization of network resources in dynamic scenarios allowing for unpredictable changes in traffic demands, network infrastructure availability, and customer characteristics. Experiments based on emulation as well as real testbed demonstrate the effectiveness of the SDM-EaaS strategy.

The Internet is now present in our personal and professional life, where reliability and green communications are still open issues to be addressed. Usually, clients establish Service Level Agreements (SLAs) with their Internet Service Providers (ISPs), including parameters of reliability and bandwidth. On the other hand, the ISPs aim to maximize their profit by establishing as many SLAs as possible and decreasing the energy consumption to provide their services. In this context, this paper presents an algorithm for Virtual Software Defined Network (VSDN) allocation that considers both reliability and energy efficiency. The algorithm deploys the VSDN aiming to comply with the parameters defined in SLAs, as well as to improve the energy efficiency of the ISP. Experiments using a real network topology show the effectiveness of the algorithm to deploy the VSDN with a performance 15% better than existing algorithms.

Nowadays, the multimedia content accessed by users represents 55% of the Internet traffic and it is forecast to expand to 92% by 2020. This fact increased the resource demand in access networks across the world, since multimedia traffic has high network requirements. To deal with this scenario, Internet Service Providers (ISPs) tend to apply the Edge as a Service (EaaS) approach. EaaS aims to use Network Virtualization and Network Programmability to expand the flexibility of access to edge network resources. In this context, this paper presents the Bitrate-Aware Virtual Resources Adjustment (BEAVER) mechanism, which increases the Quality of Experience (QoE) support for multimedia clients in EaaS environments. Experiments using real traffic demonstrate the effectiveness of the proposed mechanism to ensure the user's QoE.

Vehicular networks are seen as the basis for the development of intelligent transportation systems. Therefore, and in order to take advantage of the benefits from these transportation systems, the development of standards that meet the specific characteristics of vehicular networks was required. The "Wireless Access in Vehicular Environments" (WAVE) was developed in order to fulfill this need. This standard presents an architecture based on a division into multiple channels, which are set for certain types of applications, and it uses a switching mechanism for the selection of channels, since only one channel is active at a given time. However, in certain scenarios, this channel switching mechanism introduces an undesirable effect that allows different vehicles to transmit simultaneously, thus resulting in collisions. This work proposes a solution to this problem with the development of a mechanism based on the recalculation of the transmission delay, which will work along with other features, such as the broadcast suppression mechanism, in order to ensure greater performance in transmissions.

The improvement in virtualisation technologies, as well as higher data transmission rates and the popularisation of the Internet contributed to strengthen the cloud computing. This paradigm attracts more and more users to consume, and providers to offer services through the pay-as-you-go model. The users can benefit from the clouds by receiving high availability, cost reduction, load balancing, and better fault tolerance when deploying cloud services across several cloud providers instead of using a single service provider. However, the variety of charging models, quality of service (QoS), and monetary costs of virtual machines, makes it difficult to the customer to choose the best resource charging models to deploy applications. In this paper we propose a redundancy strategy based on the tenancy level among requests in order to decrease the scheduling cost and maintain QoS levels along different IaaS charging models. The strategy is modelled as an integer linear program (ILP) to compute the lowest cost when utilising virtual machines. Simulations show that the proposed approach computes schedules with smaller costs than alternative approaches.

Vehicular Ad hoc Networks (VANETs) are an emerging technology that allows vehicles to form self-organized networks without the requirement of permanent infrastructure. VANETs have opened up a myriad of on the road applications and increased their potential by providing intelligent transport systems. The envisaged applications, as well as some inherent VANET characteristics (i.e., highly dynamic topology, diverse network densities, and intermittent connectivity) make data dissemination an essential service and a challenging task in these networks. Many data dissemination protocols have been proposed in the literature. However, most of these protocols were designed to operate exclusively under dense or sparse networks. In addition, the existing solutions for data dissemination do not effectively address broadcast storm and network partition problems simultaneously. To tackle these problems, we propose a suitable multi-hop broadcast protocol named as TURBO that relies exclusively on local one-hop neighbor information to deliver messages under dense and sparse networks. We compared our protocol with other protocols from literature - AID, DBRS, GEDDAI, and simple Flooding. Simulation results show that TURBO performs data dissemination with better efficiency than other protocols, outperforming them in different scenarios in all the evaluations carried out.

Currently, the Internet is the main communication medium, however it does not guarantee Quality of Service. To contour this problem, companies establish Service Level Agreements with their Internet Service Providers, including parameters like bandwidth and reliability of the network. This paper presents an algorithm for virtual network allocation in a reliability context, where a feasible bandwidth approach and reliability calculation are used to deploy the virtual network according to the client's requirement. Simulations using a real network topology show the effectiveness of the algorithm to deploy the virtual network in a scenario of multiple cumulative requests.

MapReduce is a programming model for processing and generating large data sets, and Hadoop, a MapReduce implementation, is a good tool to handle Big Data. Cloud computing with its ubiquitous characteristic, on demand and dynamic resource provisioning at low cost has potential to be the environment to treat big data. However, using Hadoop on the cloud spends time and requires technical knowledge from users. The hybrid cloud leverages these requirements, because it's necessary to evaluate the resources in private cloud and, if necessary, obtain and prepare on-demand resources in the public cloud. Moreover, the simultaneous management of private and public domains requires an appropriate model that combines performance with minimal cost. In this paper we propose an architecture to make the orchestration of Hadoop applications in hybrid clouds. The core of the model consists of a web portal for submissions, an orchestration engine and an execution services factory. Through these three components it's possible to automate the preparation of a cross-domain cluster, performing the provisioning of files involved, managing the execution of the application, and making the results available to the user.

In hybrid clouds, the available bandwidth in inter-cloud links is quite variable. Overestimating the available bandwidth on theses channels at scheduling time can enlarge the makespan and cause deadline misses. In this paper, we propose a procedure for deflating the estimated available bandwidth used as input to cloud schedulers since schedulers are not usually designed to cope with inaccurate information on available bandwidth. The procedure is based on a multiple linear regression procedure which utilizes historical information of previous executions of workflows. Results showed that the proposed procedure can increase the number of valid schedules without increasing the makespan and cost estimations, regardless the variability in the available bandwidth during the execution of an application workflow.

To access the Internet, companies define a Service Level Agreement (SLA) with Internet Service Providers (ISPs). Nevertheless, the current Internet does not assure Quality of Service (QoS), what points toward the concept of network virtualization and software defined network (SDN) to support the Future Internet. Moreover, the initial parameters defined in SLAs may not withstand traffic changes, resulting in a lower quality experienced by users and a waste of resources for ISPs. Within this context, this paper proposes an architecture to deal with resource usage variations. The proposal aims to enhance the QoS provided by the ISPs, while improving the usage of network resources in dynamic scenarios. Experiments using real traffic demonstrate the effectiveness of the proposed architecture.

A Vehicular Ad Hoc Network (VANET) is a subclass of Mobile Ad Hoc Networks, which provides wireless communication among vehicles as well as between vehicles and roadside units. Providing safety, traffic efficiency and user comfort for drivers and passengers are promising goals of these networks. To reach these goals many envisaged applications for VANETs will rely on data dissemination, turning this task into an essential service. However, due to some inherent characteristics of VANETs, such as intermittent connectivity, highly dynamic topology, and diverse network densities, data dissemination is a challenging activity in this kind of network. Although data dissemination has been extensively studied in the literature, existing solutions do not effectively address the broadcast storm and network partition problems when considered together. To deal with both problems, we propose a network partition-aware geographical data dissemination protocol, which eliminates the broadcast storm and maximizes the data dissemination capability across network partitions with short delays and low overhead. The proposed algorithm is able to autonomically adjust message transmissions in the network. Simulation results show that our proposed approach provides good efficiency with respect to the coverage of event processing, delay and overhead.

Several data dissemination protocols in VANETs have been proposed in the literature, however, most of these protocols do not efficiently address broadcast storm and network partition problems simultaneously. This work attempts to fill this gap by proposing a suitable broadcast protocol in vehicular networks, designated GTO, that addresses both the broadcast storm and network partition problems in highway environment. In GTO protocol, all vehicles send beacon packets notifying whether there is or not the information, besides we employ the technique of zone of preference to rebroadcast messages to further vehicles. We compared the proposed protocol with the other five protocols - ATENA, DV-CAST, SRD, AID and Flooding - The results of evaluation show that our proposed protocol was more efficient to disseminate the information, within area of interest, than other five protocols in different traffic conditions.

To access the Internet, companies define a Service Level Agreement (SLA) with Internet Service Providers (ISPs). Nevertheless, the current Internet does not assure Quality of Service (QoS), what points toward the concept of virtual networks (VNs) and software defined network (SDN) to support the Future Internet. Moreover, the VN and SDN approaches can be mixed creating the Virtual Software Defined Network (VSDN), which enhances the customization capacity of the networks. Based on this context, this work proposes a similarity metric and a fuzzy decision-making model (FDMM) to support the VSDN negotiation. Experiments show the effectiveness of the proposal in providing the clients with a mechanism to compare protocols offered by providers, allowing them to identify which one best fulfills the requirements.

Software Defined Networking (SDN) has opened new ways to design, deploy, and operate networks with new abstractions and programmability at network control and data planes. In this paper, we approach SDN to embed virtual data center networks employing the Network-as-a-Service model. The proposed architecture is built upon abstractions to create a virtual topology using BGP configurations that allow an efficient mapping to a physical network of OpenFlow 1.3 switches. In the control plane, an algorithm is designed to perform efficient allocation of network resources to virtual paths based on the data plane state, such as allocated virtual networks and resource utilization metrics. Requirements such as bandwidth and resilience are used to define the tenants policies and construct the virtual topology graph mappings. The experimental evaluation on an emulated testbed shows that the proposed algorithm performs efficient load balancing and altogether yields better utilization of the physical resources under different tenant traffic patterns.

With the ever-increasing application demands, the execution of applications may require more resources than locally available. In this scenario, resources from multiple IaaS cloud providers can be leased to fulfill application requirements. In this paper we deal with the problem of scheduling workflow applications in multiple IaaS providers, where the workflow scheduler must determine on which computational resource each component of a workflow should be allocated in order to minimize the involved monetary costs. We propose the use of different levels of discrete-time intervals in linear programming to schedule workflows with deadline constraints in multiple cloud providers. Simulations shown that increasing the granularity level of time-discretization decreases the scheduler running time, although yet achieving good solutions.

The Internet has become a primary means of communication, even though it currently does not guarantee Quality of Service (QoS). In order to tackle with this problem, companies establish Service Level Agreements (SLA) with their providers, including the reliability of services. This paper shows an algorithm for virtual network allocation in a reliability context, where some techniques of disjoint path and reliability calculation are used to deploy the virtual network according to the client's specification. Simulations using real network topologies show the capacity of the algorithm to deploy the virtual network according to the client requirements.

The so-called hybrid cloud is the composition of an infrastructure that comprises private resources as well as public resources leased from public clouds. Hybrid clouds can be utilized for the execution of applications composed of dependent jobs, usually modeled as workflows. In this scenario, a scheduler must distribute the components of the workflow onto available resources considering the communication demands and the available bandwidth in network links. However, such information can be imprecise, and consequently decisions on resource allocation can be ineffective. In this paper, we evaluate scheduling algorithms in the face of imprecise information on the availability of communication channels. Results showed that schedules are negatively affected by the unforeseen variations in bandwidth during the execution of the application.

Cloud computing is being used to avoid maintenance costs and upfront investment, while providing elasticity to the available computational power in a pay-per-use basis. Customers can make use of the cloud as a software (SaaS), platform (PaaS), or infrastructure (IaaS) provider. When one customer utilizes an environment provided by a SaaS cloud, she is unaware of any details about the computational infrastructure where her requests are being processed. Therefore, such infrastructure can be composed of computational resources from a datacenter owned by the SaaS or its resources can be leased from a cloud infrastructure provider. In this paper we present an integer linear program (ILP) formulation for the problem of scheduling SaaS customer's workflows into multiple IaaS providers where SLA exists at two levels. In addition, we present heuristics to solve the relaxed version of the presented ILP. Simulation results show that the proposed ILP is able to find low-cost solutions for short deadlines, while the proposed heuristics are effective when deadlines are larger.

Network virtualization is a viable solution to interconnect virtual resources providing isolation and to promote the architecture pluralism for the Future Internet. The virtualization causes an increase of complexity that could be handled by autonomic computing. We developed a multi-agent architecture for autonomic management of virtual networks in infrastructure providers. A prototype system focusing on self-healing was implemented and evaluated on real and simulated environments. The experimental results show the ability of the system to quickly self-heal virtual networks in the presence of failure with a marginal impact on resource allocation.

A supply chain comprises several different kinds of actors that interact either in an ad hoc fashion (e.g. an eventual deal) or in a previously well-planned way. In the latter, how the interactions develop is described in contracts that are agreed on before the interactions start. This agreement may involve several partners, thus a multi-party contract is better suited than a set of bi-lateral contracts. If one is willing to negotiate automatically such kind of contracts, an appropriate negotiation protocol should be at hand. However, the ones for bi-lateral contracts are not suitable for multi-party contracts, e.g. the way to achieve consensus when only two negotiators are haggling over some issues is quite different if there are several negotiators involved. In the first case, a simple bargain would suffice, but in the latter a ballot process is needed. This paper briefly presents our negotiation protocol for electronic multi-party contracts which seamlessly combines several negotiation styles. It also elaborates on the main negotiation patterns the protocol allows for: bargain (for peer-to-peer negotiation), auction (when there is competition among the negotiators) and ballot (when the negotiation aims at consensus) and presents other patterns that can be built on these basic ones. Finally, it describes an implementation of this protocol based on Web services, and built on the YAWL Workflow Management System.

Cloud computing has recently emerged as a convergence of concepts such as cluster computing, grid computing, utility computing, and virtualization. In hybrid clouds, the user has its private cloud available for use, but she can also request new resources to public clouds in a pay-per-use basis when there is an increase in demand. In this scenario it is important to decide when and how to request these new resources to satisfy deadlines and/or to get a reasonable execution time, while minimizing the monetary costs involved. In this paper we propose a strategy to schedule service workflows in a hybrid cloud. The strategy aims at determining which services should use paid resources and what kind of resource should be requested to the cloud in order to minimize costs and meet deadlines. Experiments suggest that the strategy can decrease the execution costs while maintaining reasonable execution times.

The evolution of network technologies brought increasing management complexity of networking infrastructure and protocols. Cognitive networking was introduced to deal with such complexity. This work presents a cognitive algorithm for cross-layer performance management which is the core of a decentralized framework for self-configuration of communication protocols. We illustrate the proposed solution for the joint reconfiguration of protocol parameters at different layers. The cognitive joint adaptation of TCP congestion window and MAC layer data rate is carried out as a proof of concept. Simulation results show performance improvement given by the proposed approach under changing network conditions.

Among the numerous DAG scheduling heuristics suitable for heterogeneous systems, the Heterogeneous Earliest Finish Time (HEFT) heuristic is known to give good results in short time. In this paper, we propose an improvement of HEFT, where the locally optimal decisions made by the heuristic do not rely on estimates of a single task only, but also look ahead in the schedule and take into account information about the impact of this decision to the children of the task being allocated. Preliminary simulation results indicate that the lookahead variation of HEFT can effectively reduce the makespan of the schedule in most cases without making the algorithm's execution time prohibitively high.

Component-based software engineering has recently emerged as a promising solution to the development of system-level software. Unfortunately, current approaches are limited to specific platforms and domains. This lack of generality is particularly problematic as it prevents knowledge sharing and generally drives development costs up. In the past, we have developed a generic approach to component-based software engineering for system-level software called OpenCom. In this paper, we present OpenComL an instantiation of OpenCom to Linux environments and show how it can be profiled to meet a range of system-level software in Linux environments. For this, we demonstrate its application to constructing a programmable router platform and a middleware for parallel environments.

Although a growing number of devices have the support for parallel processing, parallelism is not widely exploited, as it should be. This can be illustrated by the fact that all Apple desktops and laptops are currently supplied with one or more dual- core processors. Despite this, parallel programming in popular languages such as Java is not widely encouraged and often only recommended as a last resort. In addition, it is likely that the next generation parallel applications will have to operate within a diverse range of heterogeneous devices ranging from supercomputers to sensors. This paper proposes a flexible component-based middleware that aims at facilitating the construction of deadlock-free parallel and concurrent applications for heterogeneous environments. The middleware is particularly targeted to tailor applications to the target need and environment. For our prototyping, we implemented plu- gins that are capable of deploying JCSP (CSP library for Java programmers) and OCCam-pi processes. Both JCSP and OCCam-pi make use of the CSP disciplines. The CSP (Communicating Sequential Processes) paradigm helps us to avoid concurrency problems such as deadlocks. It should be stressed that there is no bias towards these languages as the proposed middleware is highly extensible.

Distributed transaction processing hinges on enforcing agreement among the involved resource managers on whether to commit or abort transactions (atomicity) and on making their updates permanent (durability). This paper introduces a log service which abstracts these tasks. The service logs commit and abort votes as well as the updates performed by each resource manager. Based on the votes, the log service outputs the transaction's outcome. The service also totally orders non-concurrent transactions and makes the sequence of updates performed by each resource manager available as a means to consistently recover resource managers without relying on their local state. Besides the specification, we overview two highly available implementations of this service and present an experimental performance evaluation.

Abstract A scheduler must consider the heterogeneity and communication delays when scheduling dependent tasks on a grid. The task‐scheduling problem is NP‐Complete in general, which led us to the development of a heuristic for the associated optimization problem. In this work we present a dynamic adaptive approach to schedule dependent tasks onto a grid based on the Xavantes grid middleware. The developed dynamic approach is applied to the Path Clustering Heuristic, and introduces the concept of rounds, which take turns sending tasks to execution and evaluating the performance of the resources. The adaptive extension changes the size of rounds during the process execution, taking task attributes and resources performance as parameters, and it can be adopted in other task schedulers. The experiments show that the dynamic round‐based and adaptive schedule can minimize the effects of performance losses while executing processes on the grid. Copyright © 2007 John Wiley & Sons, Ltd.

Due to their installation and management simplicity, Wireless Mesh Networks (WMNs) have become a natural way to deliver wireless coverage for local, campus and metropolitan areas. In order to provide backhaul support, it is necessary to enhance the capacity of WMNs. In this paper, a scalable link quality routing protocol for multi-radio WMNs is proposed. We incorporate a local link quality metric and multi-radio support in the OLSR (Optimized Link State Routing) protocol. This simple and scalable approach helps to find shortest paths with better quality. Simulations were conducted and the results showed expressive performance improvements of the proposed protocol over the original OLSR, with a minimum overhead increase. Algorithms, Communication system routing, Computer network performance, Wireless Mesh Networks.

A distributed control plane architecture enhances transport networks with dynamic and flexible connection control. As a result, it allows the provisioning of advanced connectivity services, like Virtual Private Networks (VPNs), on layer 1 switching networks. Such Layer 1 VPN (LI VPN) services enable multiple customer networks to share a single transport network. In this work, we propose an architecture for LI VPN management. Our approach has been to use Policy-Based Management (PBM) to provide customers with some level of control and management over their LI VPNs. We also present a prototype implemented to validate the proposed architecture and discuss implications of policies for LI VPN configuration management.

One of the great challenges to be faced in order to enable the success of future Web-based applications is to find effective ways to handle with the interoperability demands. In this context, Service-Oriented Architectures and Web Services technology are being considered as the most affordable solution topromote interoperability, by applying strategies like Service Composition. Nevertheless, most composition approaches applied nowadays in real world contexts lack dynamism. In fact, there is not yet a consensus regarding what would really be a dynamic composition. In this paper we propose some criteriato identify the levels of dynamism and automatization in service compositions. Furthermore, taking into account a model driven approach, we propose a strategy where different techniques can be used to make compositions more dynamic and automatic. This strategy is then exemplified and discussed considering an e-Government composition scenario.

In this paper we present a Web Services-based approach to provide connections between optical domains. The architecture we describe here consists of a virtual topology service, an end-to-end connection service and an end-to-end interdomain negotiation service. All of them were implemented using the Web services technology. In this work we shortly introduce the architecture and focus mainly on the performance analysis. In order to validate our approach, a prototype that implements the services mentioned above has been developed and evaluated in terms of time, scalability and bandwidth consumption to establish end-to-end interdomain optical connections.

Provisioning of interdomain connections has been a constant challenge for providers. Clients (e.g. access networks) are asking for services that span across multiple different domains and each domain has its local constraints (policies) that must be analyzed before accepting an end-to-end (e2e) connection. In this paper we present a service oriented architecture-based approach by which basic services are modeled and composed to create more complex services. Such approach considers the establishment of e2e interdomain connections in optical networks. The architecture we present here consists of a virtual topology service, an end-to-end connection service and an end-to-end negotiation service. All of them were implemented using the Web services technology

Abstract Grid computing is a model for wide‐area distributed and parallel computing across heterogeneous networks in multiple administrative domains. It strives to provide breakthrough computing power at low cost. Nowadays there are dozens of academic and commercial products that allow execution of isolated tasks on Grids, but few products support the coordination of long‐running processes in a distributed fashion. In order to address the subject, this paper presents a programming model and a middleware that support the hierarchical execution of structured processes using available nodes in a Grid environment. Their advantages are adaptable and structured coordination of activities, with better execution scalability, performance, reliability and easy monitoring. This paper also presents results that demonstrate the efficiency of this structured model, supporting dynamic adaptation of process execution through the use of an application that searches for prime numbers. Copyright © 2005 John Wiley & Sons, Ltd.

The Service-Oriented Architecture promises to be an affordable solution for the integration of heterogeneous systems through the Internet. In the e-Business field, this promise represents a great chance for companies to increase competitiveness and to enable the enactment of new collaborative e-Business processes. In this paper, we present a Virtual Marketplace infrastructure, the VM-Flow, which uses Dynamic Composition of Web Services (Orchestration and Choreography) as a fundamental technique to enable interorganizational business interactions in the context of Dynamic Virtual Enterprises. The VM-Flow platform is workflow-based and also introduces a series of interaction policies to deal with aspects like autonomy and privacy. A platform model is presented together with details on the infrastructure prototype and on an application built over it.

In this paper we present a policy-based admission control architecture responsible for managing the installation and aggregation of packet-based LSPs within lightpaths (optical LSPs). We have defined some policies in order to reduce the optical network overhead to remove and reroute lower priority LSPs. The architecture is composed of an admission control and a policy manager and the performed simulations indicated that the number of LSP removals is smaller when policies are applied.

Abstract Recent activities in Grid computing point in the direction of an open service architecture merging computational infrastructure with Grid services and Web services. We also see advantages in adding facilities offered by distributed object computing environments with their interoperable references and services. The use of open service architectures introduces the possibility of composing structures of nested services. In this paper we discuss architectural aspects of middleware for Grid computing based on an infrastructure of distributed clusters and/or also services, and an access portal as a demonstration project in progress. Copyright © 2004 John Wiley & Sons, Ltd.

The component technologies have been more and more developed and used to speed up the development of (distributed) applications. The Object Management Group (OMG) has developed a model for CORBA components, which briefly describes the deployment of CORBA components without many details. This paper presents and discusses some implementation aspects and experimental results obtained by using an extended deployment model for CORBA Components previously proposed by the authors.

Standard client-server workflow management systems are usually designed as client-server systems. The central server is responsible for the coordination of the workflow execution and, in some cases, may manage the activities database. This centralized control architecture may represent a single point of failure, which compromises the availability of the system. We propose a fully distributed and configurable architecture for workflow management systems. It is based on the idea that the activities of a case (an instance of the process) migrate from host to host, executing the workflow tasks, following a process plan. This core architecture is improved with the addition of other distributed components so that other requirements for Workflow Management Systems, besides scalability, are also addressed. The components of the architecture were tested in different distributed and centralized configurations. The ability to configure the location of components and the use of dynamic allocation of tasks were effective for the implementation of load balancing policies.

Electronic commerce applications are lacking a bilateral negotiation model which provides the bargaining between two participants (supplier and consumer) in order to buy and sell goods. This paper proposes a negotiation protocol between two participants, as well as the similarity measures which were implemented to find a similar product when a specific one could not be found. The proposed protocol follows the bilateral model approved by the OMG. The negotiation model is composed of selling and buying Grasshopper mobile agents, which negotiate between themselves in order to get the best deal. The negotiation of the price is based on the Kasbah model. The catalogs in the model are implemented in XML to provide the interoperability among different systems. A simple prototype has been implemented to verify the viability of this concept.

Standard client-server workflow management systems have an intrinsic scalability limitation: the central server is a bottleneck for large scale applications. It is also a single fault paint that may disable the whole system. We propose a fully distributed architecture for workflow management systems. It is based on the idea that the case (an instance of the process) migrates from host to host, according to the process definition specification, as the corresponding activities are executed. This basic architecture is improved so that other requirements for Workflow Management Systems, besides scalability, are also contemplated. A CORBA-based implementation of such architecture is discussed, with both its limitations and positive points described.

Migration distribution transparency is considered in the context of multi-agent systems. A mobile agent architecture is proposed with an availability service and a transparency interface. Transparent mobility of agents is explored in applications using overall balancing of resources. The search for a new destination agency follows a transparent location and selection. Final balancing takes place at the level of requests and callbacks. Transparency is goal oriented.

The ability of heterogeneous systems to cooperate in problem solving is a real necessity that has been growing due to the increasing development of distributed processing technology. This necessity is driving the development of more suitable solutions. The CORBA (Common Object Request Broker Architecture) specification presents an architecture which allows interoperability among heterogeneous distributed environment applications. However, because of the great flexibility offered in implementation decisions, many problems arise in attempting to extend interoperability between two ORBs developed by different technologies. This paper discusses these problems and their solutions and presents a set of operations to support a bridging mechanism extending access and location transparencies (which are considered fundamental for a distributed environment) to work beyond an ORB scope. A scheme to provide relocation transparency, extended to support interoperability, is also proposed. Finally, an implementation of these mechanisms over an ORB prototype, developed at UNICAMP, and ORBeline (a commercial product) is described.

In the last years, with the evolution of the communication and processing technologies, the field of multimedia cooperative applications in open distributed environments is increasing steadily. Aiming at these environments, where services may be offered in an open manner, this work presents some results in the development of the Multiware Platform. The design of this platform combines ideas from both the RM-ODP (Reference Model for Open Distributed Processing) and existent industrial specifications and products for distributed processing (e.g. ANSAware and CORBA). The platform offers functionalities to support and facilitate the development, use and management of multimedia cooperative applications.>