Service Level Agreement Enforcement Research Articles

Performance Assessment of an ITU-T Compliant Machine Learning Enhancements for 5G RAN Network Slicing

Network slicing is a technique introduced by 3GPP to enable multi-tenant operation in 5 G systems. However, the support of slicing at the air interface requires not only efficient optimization algorithms operating in real time but also its tight integration into the 5 G control plane. In this paper, we first present a priority-based mechanism enabling defined performance isolation among slices competing for resources. Then, to speed up the resource arbitration process, we propose and compare several supervised machine learning (ML) techniques. We show how to embed the proposed approach into the ITU-T standardized ML architecture. The proposed ML enhancement is evaluated under realistic traffic conditions with respect to the performance criteria defined by GSMA while explicitly accounting for 5 G millimeter wave channel conditions. Our results show that ML techniques are able to provide suitable approximations for the resource allocation process ensuring slice performance isolation, efficient resource use, and fairness. Among the considered algorithms, polynomial regressions show the best results outperforming the exact solution algorithm by 5–6 orders of magnitude in terms of execution time and both neural network and random forest algorithms in terms of accuracy (by 20–40 %), sensitiveness to workload variations and training sample size. Finally, ML algorithms are generally prone to service level agreements (SLA) violation under high load and time-varying channel conditions, implying that an SLA enforcement system is needed in ITU-T's 5 G ML framework.

Proof-of-Monitoring (PoM): A Novel Consensus Mechanism for Blockchain-Based Secure Service Level Agreement Management

In the current 5th Generation (5G) networking paradigm, the enforcement of Service Level Agreements (SLAs) is a non-trivial measure to ensure the scope and the quality of services and standards between tenants and service providers (SPs). On top of this, Secure Service Level Agreements (SSLA) are introduced to ensure that SPs deliver the most critical and required security-related standards defined in the contract, such as integrity, confidentiality, availability, non-repudiation, and privacy assurance. However, with the tendency for more distributed and multi-stakeholder networking architectures in next-generation networks, the management process of such SSLAs will be challenging due to the diversified security vulnerabilities and complexity of underlying technologies. Although blockchain is emerging as a platform to facilitate such distributed SSLA/SLA management frameworks, its currently available consensus mechanisms are more generic. Still, they need to improve in terms of applying in multi-stakeholder networks. Therefore, this paper presents a novel consensus mechanism called Proof-of-Monitoring (PoM) for a blockchain-based novel SSLA management framework. Moreover, we provide details about the prototype implementation of our proposed consensus algorithm and SSLA management framework. It is proven by comparing our proposal with the other existing solutions that our solution outperforms in many aspects, such as energy consumption, computation cost, and security features.

How to Design Autonomous Service Level Agreements for 6G

With the growing demand for network connectivity and diversity of network applications, one primary challenge that network service providers are facing is managing the commitments for Service Level Agreements (SLAs). Service providers typically monitor SLAs for management tasks such as improving their service quality, customer billing and future network planning. Network service customers, on their side, monitor services provided to them, to optimize their network usage and apply, when required, penalties related to service failures. In future 6G networks, critical network applications such as remote surgery and connected vehicles will require these SLAs to be more dynamic, flexible, and automated to match their diverse requirements on network services. Moreover, these SLAs should be transparent to all stakeholders to address the trustworthiness on network services and service providers required by critical applications. Currently, there is no standardized method to immutably record and audit SLAs, leading to challenges in aspects such as SLA enforcement and accountability - traits essential for future network applications. This work explores new requirements for future service contracts, that is, on the evolution of SLAs. Based on those new requirements, we propose an end to end layered SLA architecture leveraging Distributed Ledger Technology (DLT) and smart contracts. Our architecture is inheritable by an existing telco-application layered architectural frameworks to support future SLAs. We also discuss some limitations of DLT and smart contracts and provide several directions of future studies.

Distributed service‐level agreement management with smart contracts and blockchain

SummaryThe current cloud market is dominated by a few providers, which offer cloud services in a take‐it‐or‐leave‐it manner. However, the dynamism and uncertainty of cloud environments may require the change over time of both application requirements and service capabilities. The current service‐level agreement (SLA) management solutions cannot easily guarantee a trustworthy, distributed SLA adaptation due to the centralized authority of the cloud provider who could also misbehave to pursue individual goals. To address the above issues, we propose a novel SLA management framework, which facilitates the specification and enforcement of dynamic SLAs that enable one to describe how, and under which conditions, the offered service level can change over time. The proposed framework relies on a two‐level blockchain architecture. At the first level, the smart SLA is transformed into a smart contract that dynamically guides service provisioning. At the second level, a permissioned blockchain is built through a federation of monitoring entities to generate objective measurements for the smart SLA/contract assessment. The scalability of this permissioned blockchain is also thoroughly evaluated. The proposed framework enables creating open distributed clouds, which offer manageable and dynamic services, and facilitates cost reduction for cloud consumers, while it increases flexibility in resource management and trust in the offered cloud services.

Trusted UAV Network Coverage Using Blockchain, Machine Learning, and Auction Mechanisms

The UAV is emerging as one of the greatest technology developments for rapid network coverage provisioning at affordable cost. The aim of this paper is to outsource network coverage of a specific area according to a desired quality of service requirement and to enable various entities in the network to have intelligence to make autonomous decisions using blockchain and auction mechanisms. In this regard, by considering a multiple-UAV network where each UAV is associated to its own controlling operator, this paper addresses two major challenges: the selection of the UAV for the desired quality of network coverage and the development of a distributed and autonomous real-time monitoring framework for the enforcement of service level agreement (SLA). For a suitable UAV selection, we employ a reputation-based auction mechanism to model the interaction between the business agent who is interested in outsourcing the network coverage and the UAV operators serving in closeby areas. In addition, theoretical analysis is performed to show that the proposed auction mechanism attains a dominant strategy equilibrium. For the SLA enforcement and trust model, we propose a permissioned blockchain architecture considering Support Vector Machine (SVM) for real-time autonomous and distributed monitoring of UAV service. In particular, smart contract features of the blockchain are invoked for enforcing the SLA terms of payment and penalty, and for quantifying the UAV service reputation. Simulation results confirm the accuracy of theoretical analysis and efficacy of the proposed model.

Enabling a Blockchain-Based IoT Edge

Within many industry verticals, the Internet of Things provides the means to collect and analyze crucial data for optimizing system performance. The technical evolution of IoT is shifting its computational capabilities away from centralized cloud platforms to a decentralized IoT edge. The IoT edge faces challenges in providing fully decentralized security mechanisms, as well as built-in guarantees for user-data privacy. In recent years, blockchain has been viewed as a potential fabric for a secure, decentralized IoT edge due to its inherent features of fault tolerance, transparency, and enforcement of service level agreements through smart contracts. Despite their virtues, blockchains have their fair share of challenges in being integrated into IoT. In this article, we discuss these challenges, as well as candidate solutions for integrating blockchains into the IoT edge.

A design space for dynamic service level agreements in OpenStack

This paper does a systematic review of the possible design space for cloud-hosted applications that may have changing resource requirements that need to be supported through dynamic service level agreements (SLAs). The fundamental SLA functions are reviewed: Admission Control, Monitoring, SLA Evaluation, and SLA Enforcement - a classic autonomic control cycle. This is followed by an investigation into possible application requirements and SLA enforcement mechanisms. We then identify five basic Load Types that a dynamic SLA system must manage: Best Effort, Throttled, Load Migration, Preemption and Spare Capacity. The key to meeting application SLA requirements under changing surge conditions is to also manage the spare surge capacity. The use of this surge capacity could be managed by one of several identified load migration policies. A more detailed SLA architecture is presented that discusses specific SLA components. This is done in the context of the OpenStack since it is open source with a known architecture. Based on this SLA architecture, a research and development plan is presented wherein fundamental issues are identified that need to be resolved through research and experimentation. Based on successful outcomes, further developments are considered in the plan to produce a complete, end-to-end dynamic SLA capability. Executing on this plan will take significant resources and organization. The NSF Center for Cloud and Autonomic Computing is one possible avenue for pursuing these efforts. Given the growing importance of cloud performance management in the wider marketplace, the cloud community would be well-served to coordinate cloud SLA development across organizations such as the IEEE, Open Grid Forum, and the TeleManagement Forum.

SLA negotiation and enforcement policies for revenue maximization and client classification in cloud providers

In Cloud Computing markets, owners of computing resources negotiate with their potential clients to sell computing power. The terms of the Quality of Service (QoS) to be provided as well as the economic conditions are established in a Service-Level Agreement (SLA). The common objective of a Cloud provider is to maximize its economic profit. However, there are situations in which providers must differentiate the SLAs with respect to the type of client that is willing to access the resources or the agreed QoS, e.g. when the hardware resources are shared between users of the company that own the resources and external users.This article proposes two sets of policies to manage SLAs with respect to the business objectives of a Cloud provider: Revenue Maximization or classification of clients. The criterion to classify clients is established according to the relationship between client and provider (external user, internal or another privileged relationship) and the QoS that the client purchases (cheap contracts or extra QoS by paying an extra fee). The validity of the policies is demonstrated through exhaustive experiments.

Cloud resource provisioning and SLA enforcement via LoM2HiS framework

SUMMARYCloud computing represents a novel on‐demand computing technology where resources are provisioned in compliance to a set of predefined non‐functional properties specified and negotiated by means of service level agreements (SLAs). Currently, cloud providers strive to achieve efficient SLA enforcement strategies to avoid costly SLA violations during application provisioning and to timely react to failures and environmental changes. These strategies include advanced application deployment mechanisms and appropriate resource monitoring concepts. In terms of cloud resource monitoring, providers tend to adopt existing monitoring tools, such as those from grid environments. However, those tools are usually restricted to locality and homogeneity of monitored objects, are not scalable, and do not support mapping of low‐level resource metrics (e.g., system uptime and downtime) to high‐level application‐specific SLA parameters (e.g., system availability). In this paper, we present a novel low‐level metrics to high‐level SLA (LoM2HiS) framework for managing the monitoring of low‐level resource metrics and mapping them to high‐level SLAs and an application deployment mechanism for scheduling and provisioning applications in clouds. The LoM2HiS framework provides the application deployment mechanism with monitored information and SLA violation prevention techniques, thereby ensuring the performance of the applications and thus increasing the revenue of the cloud provider by avoiding SLA violation penalty cost. This framework is the building block of the Foundations of Self‐governing ICT Infrastructures project, which intends to facilitate autonomic SLA management and enforcement. Thus, the LoM2HiS framework detects future SLA violation threats and can notify the knowledge component to act so as to avert the threats. We discuss in detail the conceptual design of the LoM2HiS framework and the application deployment mechanism including their implementations. Finally, we present our evaluation results based on a use‐case scenario demonstrating the usage of the LoM2HiS framework in a real cloud environment. Copyright © 2012 John Wiley & Sons, Ltd.

Service level agreement for multithreaded processors

Multithreading is widely used to increase processor throughput. As the number of shared resources increase, managing them while guaranteeing predicted performance becomes a major problem. Attempts have been made in previous work to ease this via different fairness mechanisms. In this article, we present a new approach to control the resource allocation and sharing via a service level agreement (SLA)-based mechanism; that is, via an agreement in which multithreaded processors guarantee a minimal level of service to the running threads. We introduce a new metric, C SLA , for conformance to SLA in multithreaded processors and show that controlling resources using with SLA allows for higher gains than are achievable by previously suggested fairness techniques. It also permits improving one metric (e.g., power) while maintaining SLA in another (e.g., performance). We compare SLA enforcement to schemes based on other fairness metrics, which are mostly targeted at equalizing execution parameters. We show that using SLA rather than fairness based algorithms provides a range of acceptable execution points from which we can select the point that best fits our optimization target, such as maximizing the weighted speedup (sum of the speedups of the individual threads) or reducing power. We demonstrate the effectiveness of the new SLA approach using switch-on-event (coarse-grained) multithreading. Our weighted speedup improvement scheme successfully enforces SLA while improving the weighted speedup by an average of 10% for unbalanced threads. This result is significant when compared with performance losses that may be incurred by fairness enforcement methods. When optimizing for power reduction in unbalanced threads SLA enforcement reduces the power by an average of 15%. SLA may be complemented by other power reduction methods to achieve further power savings and maintain the same service level for the threads. We also demonstrate differentiated SLA, where weighted speedup is maximized while each thread may have a different throughput constraint.

Lifetime service level agreement management with autonomous agents for services provision

In the web services environment, service level agreements (SLA) refers to mutually agreed understandings and expectations between service consumers and providers on the service provision. Although management of SLA is critical to wide adoption of web services technologies in the real world, support for it is very limited nowadays, especially in web service composition scenarios. There lacks adequate frameworks and technologies supporting various SLA operations such as SLA formation, enforcement, and recovery. This paper presents a novel agent-based framework which utilises the agents’ ability of negotiation, interaction, and cooperation to facilitate autonomous SLA management in the context of service composition provision. Based on this framework, mechanisms for autonomous SLA operations are proposed and discussed. Results from simulations show that by integrating agents and web services the framework can address issues of SLA management drawn from sophisticated service composition scenarios.

Distributed Computing Techniques for Wireless Messaging Systems

This paper considers the application of distributed computing techniques to mobile telecommunications and wireless messaging infrastructures particularly to Service Level Agreement (SLA) enforcement. It presents novel distributed techniques based on the application of InfiniBand technology over the RDMA channel Interface to develop a distributed Service Level Agreement and enforcement solution for the generalised mobile messaging infrastructure. The paper also reports on the construction of a distributed SLA application that is able to handle extremely high throughput and still provide the required data integrity. We developed an SLA quota management model, deployed across distributed servers that provide a comparison illustrating the aftermath of deploying the SLA enforcement solution over InfiniBand and Ethernet technologies respectively.

The WSLA Framework: Specifying and Monitoring Service Level Agreements for Web Services

We describe a novel framework for specifying and monitoring Service Level Agreements (SLA) for Web Services. SLA monitoring and enforcement become increasingly important in a Web Service environment where enterprise applications and services rely on services that may be subscribed dynamically and on-demand. For economic and practical reasons, we want an automated provisioning process for both the service itself as well as the SLA managment system that measures and monitors the QoS parameters, checks the agreed-upon service levels, and reports violations to the authorized parties involved in the SLA management process. Our approach to these issues is presented in this paper. The Web Service Level Agreement (WSLA) framework is targeted at defining and monitoring SLAs for Web Services. Although WSLA has been designed for a Web Services environment, it is applicable as well to any inter-domain management scenario, such as business process and service management, or the management of networks, systems and applications in general. The WSLA framework consists of a flexible and extensible language based on XML Schema and a runtime architecture comprising several SLA monitoring services, which may be outsourced to third parties to ensure a maximum of objectivity. WSLA enables service customers and providers to unambiguously define a wide variety of SLAs, specify the SLA parameters and the way they are measured, and relate them to managed resource instrumentations. Upon receipt of an SLA specification, the WSLA monitoring services are automatically configured to enforce the SLA. An implementation of the WSLA framework, termed SLA Compliance Monitor, is publicly available as part of the IBM Web Services Toolkit.