Catalin Meirosu

Research Directions in Network Service Chaining

Network Service Chaining (NSC) is a service deployment concept that promises increased flexibility and cost efficiency for future carrier networks. NSC has received considerable attention in the standardization and research communities lately. However, NSC is largely undefined in the peer-reviewed literature. In fact, a literature review reveals that the role of NSC enabling technologies is up for discussion, and so are the key research challenges lying ahead. This paper addresses these topics by motivating our research interest towards advanced dynamic NSC and detailing the main aspects to be considered in the context of carrier-grade telecommunication networks. We present design considerations and system requirements alongside use cases that illustrate the advantages of adopting NSC. We detail prominent research challenges during the typical lifecycle of a network service chain in an operational telecommunications network, including service chain description, programming, deployment, and debugging, and summarize our security considerations. We conclude this paper with an outlook on future work in this area.

Decentralized In-Network Management for the Future Internet

In-network management (INM) is a new paradigm for the management of the future Internet that is based on the principles of decentralization and self-organization. Its goal is to overcome the limitations of traditional network management and to achieve scalable and robust management systems with low complexity for large-scale, dynamic network environments. In this paper, we describe a framework for INM that provides a systematic approach to the embedding of management algorithms within the elements of a communication networks. In addition, we demonstrate the benefits of decentralized management in the context of two key management functions, namely real-time monitoring and event handling.

Architectural principles and elements of in-network management

Recent endeavors in addressing the challenges of the current and future Internet pursue a clean slate design methodology. Simultaneously, it is argued that the Internet is unlikely to be changed in one fell swoop and that its next generation requires an evolutionary design approach. Recognizing both positions, we claim that cleanness and evolution are not mutually exclusive, but rather complementary and indispensable properties for sustainable management in the future Internet. In this paper we propose the in-network management (INM) paradigm, which adopts a clean slate design approach to the management of future communication networks that is brought about by evolutionary design principles. The proposed paradigm builds on embedded management capabilities to address the intrinsic nature, and hence, close relationship between the network and its management. At the same time, INM assists in the gradual adoption of embedded self-managing processes to progressively achieve adequate and practical degrees of INM. We demonstrate how INM can be exploited in current and future network management by its application to P2P networks.

Scalable Software Defined Monitoring for Service Provider DevOps

Technology trends such as Cloud, SDN, and NFV are transforming the telecommunications business, promising higher service flexibility and faster deployment times. They also allow for increased programmability of the infrastructure layers. We propose to split selected monitoring control functionality onto node-local control planes, thereby taking advantage of processing capabilities on programmable nodes. Our software defined monitoring approach provides telecom operators with a way to handle the trade off between high-granular monitoring information versus network and computation loads at central control and management layers. To illustrate the concept, a link rate monitoring function is implemented using node-local control plane components. Furthermore, we introduce a messaging bus for simple and flexible communication between monitoring function components as well as control and management systems. We investigate scalability gains with a numerical analysis, demonstrating that our approach would generate thousand fold less monitoring traffic while providing similar information granularity as a naive SNMP implementation or an Open Flow approach.

Service provider DevOps for large scale modern network services

Network service providers are facing challenges for deploying new services mainly due to the growing complexity of software architecture and development process. Moreover, the recent architectural innovation of network systems such as Network Function Virtualization (NFV), Software-defined Networking (SDN), and Cloud computing increases the development and operation complexity yet again. One of the emerging solutions to this problem is a novel software development concept, namely DevOps, that is widely employed by major Internet software companies. Although the goals of DevOps in data centers are well-suited for the demands of agile service creation, additional requirements specific to the virtualized and software-defined network environment are important to be addressed from the perspective of modern network carriers. In this paper, we thoroughly debate DevOps requirements for developing a modern service creation platform by taking EU FP7 project UNIFY as a reference architecture and suggest the corresponding extensions of UNIFY interfaces that meet the discovered requirements.

GreenSDN: Bringing energy efficiency to an SDN emulation environment

A significant number of green, energy-saving network protocols have been invented in recent years in response to demand for reducing the amount of energy consumed by network infrastructure. In this paper, we report on the difficulties we encountered when building an SDN environment that could emulate energy saving protocols operating at different layers of the network. We propose solutions, based on the Mininet environment and the POX Openflow controller, that emulate the effects of three different energy saving protocols. Our approach is validated by comparing energy savings obtained by activating these protocols in an emulated network topology inspired by the Brazilian Research Network.

Softwarization of carrier networks

Abstract Carrier networks are faced with continuous transformations of their technology platforms in order to keep up with the changing customer demands. This paper will show how the transition from stovepipe networks to layered architectures enabled the shift to a future network design based on a network operation system (NetOS) operating the ICT fabric containing merely any kind of resources. Basic, underlying concepts are presented and detailed how they will be integrated in this environment. Software components and related development and management processes are becoming an integrated part of this future carrier environment, representing a softwarization of carrier networks. Key technology enablers are Software Defined Networking and Network Function Virtualisation as well as general availability of compute, storage and networking resources. Existing “Network as a Service” approach benefit from this improvements with virtualization, control plane flexibility and adoption of Operation, Administration and Maintenance (OAM) feature to the latest developments. But carrier services will need additional improvements, resulting in the the presented paradigm of “Generic Resources as a Service”. This novel concept will fulfill most demands for flexible service composition, multi-provider and -domain support, automated deployment and operation.

REASoN - Reliability and/or availability evaluation for sustainable networking

Sustainable computer networking approaches adapt network node power states dynamically in response to traffic demand. This scenario imposes new challenges to the way the network resilience is evaluated based on reliability and availability metrics. The traditional assessments of reliability and availability based on Markov models or the Cut-Set and Tie-Set techniques are based on static values and do not take into account the dynamic changes observed in an energy efficient network. We present REASoN, a method that extends and merges the Markov model and the Cut and Tie set technique in a way that allows an accurate evaluation of the network reliability and availability with dynamically adjustable power levels. A numerical evaluation of our method shows that even for a reduced network topology the impacts of energy efficient operations on reliability metrics are significant to a 1st decimal digit change in reliability.

Service Provider DevOps

Although there is consensus that software defined networking and network functions virtualization overhaul service provisioning and deployment, the community still lacks a definite answer on how carrier-grade operations praxis needs to evolve. This article presents what lies beyond the first evolutionary steps in network management, identifies the challenges in service verification, observability, and troubleshooting, and explains how to address them using our Service Provider DevOps (SP-DevOps) framework. We compendiously cover the entire process from design goals to tool realization and employ an elastic version of an industry-standard use case to show how on-the-fly verification, software-defined monitoring, and automated troubleshooting of services reduce the cost of fault management actions. We assess SP-DevOps with respect to key attributes of software-defined telecommunication infrastructures both qualitatively and quantitatively, and demonstrate that SP-DevOps paves the way toward carrier-grade operations and management in the network virtualization era.

Orchestration of energy efficiency capabilities in networks

The energy demand for operating Information and Communication Technology (ICT) systems has been growing, implying in high operational costs and consequent increase of carbon emissions. Both in datacenters and telecom infrastructures, the networks represent a significant amount of energy spending. Given that, there is an increased demand for energy efficiency solutions, and several capabilities to save energy have been proposed. However, it is very difficult to orchestrate such energy efficiency capabilities, that is, coordinate or combine them in the same network, ensuring a conflict-free operation and choosing the best one for a given scenario, ensuring that a capability not suited to the current bandwidth utilization will not be applied and lead to congestion or packet loss. There is neither a way to do this taking business directives into account. In this regard, a method able to orchestrate different energy efficiency capabilities is proposed considering the possible combinations and conflicts among them, as well as the best option for a given workload and network characteristics. The business policies are refined down to the network level in order to bring high-level directives into the operation, and a Utility Function is used to combine energy efficiency and performance requirements. A Decision Tree able to determine what to do in each scenario is deployed in a Software Defined Network environment. The proposed method was validated with different experiments, testing the Utility Function, checking the extra savings when combining several capabilities, the decision tree interpolation and dynamicity aspects. The orchestration proved valid to solve the problem of finding the best combination for a given scenario, achieving additional savings due to the combination, besides ensuring a conflict-free operation. HighlightsA method able to orchestrate different energy efficiency capabilities is proposed.It considers the possible combinations and conflicts among the capabilities.It refines business policies to bring high-level directives into the operation.The method solves the problem of finding the best combination for a given scenario.And achieved additional savings, besides ensuring a conflict-free operation.