Publications in peer-reviewed journals
- V. López, J. M. Gran, R. Jimenez, J. P. Fernandez–Palacios, D. Siracusa, F. Pederzolli, O. Gerstel, Y. Shikhmanter, J. Mårtensson, P. Sköldström, T. Szyrkowiec, M. Chamania, A. Autenrieth, I. Tomkos and D. Klonidis, “The Role of SDN in Application Centric IP and Optical Networks”, Journal of Green Engineering, Vol 6 (3), July 2016.
Abstract: The paper presents the ACINO concept: Transport IP/optical networks are evolving in capacity and dynamicity of configuration. This evolution gives little to no attention to the specific needs of applications, beyond increasing raw capacity. ACINO allows applications to explicitly specify requirements for requested services in terms of high-level (technology- and configuration-agnostic) requirements. These requirements are described using intents and certain primitives which facilitate translation to technology specific configuration within the ACINO infrastructure.
- V. López, D. Konidis, D. Siracusa, Ć. Rožić, I. Tomkos, J. P. Fernández-Palacios, “On the benefits of multi-layer optimization and application awareness“, Journal of Lightwave Technology (JLT) Vol. 35 (6), pp. 1274-1279 (2017).
Abstract: The proliferation of data centers deployed within the networks of national and international operators is enabling the creation of innovative added-value services offered through consumer and business applications. This trend is constantly triggering the adaptation of network operations to the needs of the applications. Indeed, they would be better served by a flexible infrastructure that accomodates and optimizes resources based on their constraints, parameters of interest and priorities. The required network optimization can be carried out considering each single layer of the infrastructure. However, multi-layer optimization gives the opportunity to further diminish CAPEX expenditures by identifying the network configuration that jointly optimizes packet and transport resources. Unfortunately, in current deployments, the planning process is not carried out considering the impact of both layer at same time.
In this paper, we walk the reader through the manifold aspects of planning in multi-layer environments. We first provide an illustrative guide by means of relevant operator-driven use-cases, also taking into account key network operations. The following step in this evolutionary path is the introduction of application-awareness in network planning, which has the potential of increasing savings, while offering a better adaptation of network services to applications’ requirements. Without such feature, the network will become an inefficient dump pipe, with dramatically increasing costs. Finally, we discuss a use case for in-operation application-aware network planning, where optimization is dynamically performed over running networks, and we present the overall operations workflow for provisioning and optimizing resources that includes it.
Publications in conferences in 2015
- O. Gerstel and V. López, “The need for SDN in orchestration of IP over optical multi-vendor networks“, Optical Communication (ECOC), 2015 European Conference on, Valencia, 2015, pp. 1-3.
Abstract: We explain why distributed control lacks the ability to optimally control networks with multiple transport domains or both IP and optical layers. We then propose a practical architecture to fix these issues and experimentally demonstrate it over commercial IP/transport gear.
- P. Sköldström and S. Junique, “Application-centric networks and the future 5G transport“, Transparent Optical Networks (ICTON), 2015 17th International Conference on, Budapest, 2015, pp. 1-4.
Abstract: In this paper we present the Application-centric IP/Optical network concept pursued by the H2020 project ACINO, and how it could be applied as a future 5G transport network. While 5G concepts are still maturing we investigate the envisioned capabilities of a 5G network, the use-cases and the requirements different applications would have on a wired transport network for 5G. Our conclusion is that ACINO could fulfil the bandwidth, low-latency, security, and reliability requirements, in a way that differentiates between different 5G services.
- O. Gerstel, V. Lopez and D. Siracusa, “Multi-layer orchestration for application-centric networking“, Photonics in Switching (PS), 2015 International Conference on, Florence, 2015, pp. 318-320.
Abstract: We argue that the implementation of services in an IP-optical network should be driven by the needs of the specific applications, and explain why this requires a centralized orchestration architecture.
- A. Autenrieth, J. P. Elbers, T. Szyrkowiec, P. Kaczmarek and W. Kellerer, “Optical network programmability — Requirements and applications”, Photonics in Switching (PS), 2015 International Conference on, Florence, 2015, pp. 321-323.
Abstract: Datacenter operators and internet content providers require optical network programmability to efficiently interconnect distributed datacenters. This paper describes the requirements, applications and use cases for optical network programmability. Based on application scenarios, open northbound APIs with different levels of control and abstraction to address different network operator requirements which are defined. For their illustration, use cases for optical network programmability show current research directions.
Publications in conferences in 2016
- Ć. Rožić, D. Klonidis and I. Tomkos, “Latency-aware Multi-layer Network Optimization in IP-over-WDM Core Networks”, European Conference on Optical Communication (ECOC), Sept. 2016.
doi: (none yet)
Abstract: This article describes the handling of latency-sensitive traffic in an IP/optical core network. It proposes a latency-aware multi-layer network optimization approach, shows that it is superior to current solutions and evaluates the impact of propagation and electronic processing delays.
- T. Szyrkowiec, M. Santuari, M. Chamania, D. Siracusa, A. Autenrieth and V. López, “First Demonstration of an Automatic Multilayer Intent-Based Secure Service Creation by an Open Source SDN Orchestrator”, European Conference on Optical Communication (ECOC), post-Deadline Paper, Sept. 2016.
doi: (none yet)
Abstract: This article was published as a post-deadline paper. It presents an automatic intent-based encryption layer selection and configuration for a multilayer network covering IP and optical utilizing an open source SDN orchestrator. Results show that the processing impact of a secure channel creation is negligible.
- V. López, R. Vilalta, V. Uceda, A. Mayoral, R. Casellas, R. Martinez, R. Muñoz and J. P. Fernandez–Palacios, “Transport API: A Solution for SDN in Carriers Networks”, European Conference on Optical Communication (ECOC), Sep 2016.
doi: (none yet)
Abstract: This article discusses the ONF Transport API, an interface to enable control of Transport networks, including services such as topology, or connectivity setup. The paper presents the first demonstration of a connectivity service over a Dense Wavelength Division Multiplexing (DWDM) network using the Open Networking Foundation (ONF) Transport API.
- I. Maor, O. Gerstel, V. López, T, Szyrkowiec, A. Autenrieth, B. Pruessing, N. Borges, F. Fisher, G. Fabregas and J. P. Fernandez–Palacios, “First demonstration of SDN-controlled Multi-Layer Restoration and its advantage over Optical Restoration”, European Conference on Optical Communication (ECOC), Sep 2016.
doi: (none yet)
Abstract: This article presents the full implementation of a centrally orchestrated multi-layer restoration over commercial optical and IP gear. The process considers the behaviour of the IP layer and shows that compared to optical restoration, packet losses are 54% lower.
- T. Jimenez, V. López, F. Jimenez, O. Gonzalez and J. P. Fernandez, “Techno-Economic Evaluation of Optical Transport Network in Metropolitan Deployments”, European Conference on Optical Communication (ECOC), Sep 2016.
doi: (none yet)
Abstract: Optical Transport Network technology provides multiple benefits to the network operator in backbone networks. This paper presents a techno-economic comparison of optical solutions for metropolitan scenarios to assess when Optical Transport Networks should be deployed.
- V. López, D. Klonidis, D. Siracusa and J. P. Fernandez–Palacios, “Operator use cases that benefit from multi-layer optimization and application awareness”, European Conference on Optical Communication (ECOC), September, 2016.
doi: (none yet)
Abstract: This invited paper discusses multi-layer network optimization and application awareness. Multi-layer optimization enables the operators to optimize their packet and transport resources. Application awareness will provide potential savings as well as offer a better adaptation of network services to applications.
- T. Jimenez, V. López, F. Jimenez, O. Gonzalez, J.P. Fernandez–Palacios, “On the Impact of Transmission Technologies in Metropolitan Networks”, 20th International Conference on Optical Network Design and Modelling (ONDM), May 2016.
Abstract: This article assesses alternative deployments to upgrade metro networks in terms of cost efficiency. Current metro networks are deployed using IP/MPLS equipment on top of ring physical topologies. Such networks are migrating from 10G interfaces to 100G, and both the packet layer and the underlying infrastructure with its limitations must be considered.
- Ć. Rožić, D. Klonidis, I. Tomkos, “A Survey of Multi-layer Network Optimization”, 20th International Conference on Optical Network Design and Modelling (ONDM), Invited paper, May 2016.
Abstract: This invited paper gives an overview of the recent work in multi-layer network studies. First, a classification is provided, followed by the identification of the areas of study that are likely to attract more interest. Finally, a novel objective of future studies is suggested.
- F. Pederzolli, D. Siracusa, P. Sköldström, S. Junique, Ć. Rožić, D. Klonidis, T. Szyrkowiec, M. Chamania, V. Uceda, V. López, Y. Shikhmanter, O. Gerstel, “SDN application-centric orchestration for multi-layer transport networks“, International Conference on Transparent Optical Networks (ICTON), July 2016.
Abstract: This concept paper proposes the ACINO concept: an SDN-based Network Orchestrator manages multi-layer transport networks while taking explicit application requirements into account. It is based on the observation that modern IP/Optical transport networks are seldom jointly operated and optimized, and do not cater to the usually implicit requirements of applications, which ultimately drive network traffic. Network architecture and requirements are discussed; an interface is proposed to allow applications to explicitly specify their requirements in a network-agnostic manner, as well as possible strategies to optimize the network taking these requirements into account.
- D. King, C. Rotsos, A. Aguado, N. Georgalas and V. López, “The Software-Defined Transport Network: Fundamentals, Findings and Futures”, International Conference on Transparent Optical Networks (ICTON), July 2016.
Abstract: This paper introduces the concept of Software–Defined Transport Networks: SDN is an established network paradigm, architecture and principles that has attracted significant research effort in recent years. An SDN–enabled infrastructure decouples network control from forwarding and enables direct programming. Recently, there is an increasing effort to introduce SDN support in the transport layers of the network operators’ WAN infrastructure, like Layer 0 and 1. We refer to this infrastructure as the “Software Defined Transport Network”. Benefits include network management devolvement, timely connectivity provision, improved scalability, and open and flexible programmability using a well-defined API. The paper outlines the main elements of Software–Defined Transport Networks and highlights relevant Application-Based Network Operations (ABNO) enabling technologies. It also demonstrates how this technology will benefit network operators, and provides an overview of research results and deployment examples. Finally, some of the technology gaps and future research opportunities are identified.
- V. López, L. M. Contreras, O. Gonzalez de Dios, J. P. Fernandez–Palacios, “Towards a Transport SDN for Carriers Networks: An Evolutionary Perspective”, 21st European Conference on Networks and Optical Communications (NOC), invited paper, June 2016.
Abstract: This invited paper presents architectures that enable interoperability in transport networks. Some of these architectures are market ready and they have been tried in the field, while there are some approaches which are under standardization. Indeed, network operators have worked in interoperable scenarios for transport networks from several years. The main motivation is to have a rich ecosystem, which encourages the competition to have more efficient network solutions. The bandwidth increment in the transport network puts a lot of pressure to have revenues on an environment where the end-user is willing to pay less and less for the service. Software Define Networks present a new hope to achieve such a desired multi-vendor interoperability.
- A. Autenrieth, “Multilayer network planning — A practical perspective”, Optical Fiber Communications Conference and Exhibition (OFC), invited paper, March 2016.
doi: (none yet)
Abstract: This invited paper presents a pragmatic and practical multilayer network planning approach based on a candidate light path auxiliary graph model. The paper discusses how this approach can be applied to offline network planning as well as dynamic planning and provisioning of services.
- V. López, J. M. Gran, J. P. Fernandez-Palacios, D. Siracusa, F. Pederzolli, O. Gerstel, Y. Shikhmanter, J. Mårtensson, P. Sköldström, T. Szyrkowiec, M. Chamania, A. Autenrieth, I. Tomkos, D. Klonidis, “The Role of SDN in Application Centric IP and Optical Networks”, 25th European Conference on Networks and Communications (EUCNC), June 2016.
Abstract: This paper presents the ACINO concept, which is based on facilitating applications to explicitly specify requirements for requested services in terms of high-level (technology agnostic) requirements such as maximum latency or reliability. Indeed, transport IP/optical networks are evolving in capacity and dynamicity configuration. This evolution gives little to no attention to the specific needs of applications, beyond raw capacity. Using the ACINO concept, requirements are described using intents and certain primitives which facilitate translation to technology specific configuration within the ACINO infrastructure. To support this application centric approach, SDN must have a key role in this evolution. There are representative case studies where SDN gives an added value when considering not only the network but also the application layer.
- M. Santuari, T. Szyrkowiec, M. Chamania, R. Doriguzzi-Corin, V. López, D. Siracusa, “Policy-based Restoration in IP/Optical Transport Networks”, 2nd IEEE Conference on Network Softwarization (NetSoft), Demonstration paper, June 2016.
Abstract: This paper describes a demonstration presented at the 2nd IEEE Conference on Network Softwarization (NetSoft) in Seoul, South Korea, in June 2016. In case of network failure, optical and IP restoration are two different strategies that present trade-offs in terms of cost, responsiveness and offered capacity. This paper proposes the first demonstration of an IP/Optical SDN control solution (“network orchestrator”) for transport networks, which orchestrates IP or optical restoration based on the policy explicitly requested by the client application. The policy is communicated via intents, as part of the constraints that must be satisfied for a service. The orchestrator uses these intents to identify the restoration mechanism to employ in case of failure.
Publications in conferences in 2017
- Ćiril Rožić, Marco Savi, Chris Matrakidis, Dimitrios Klonidis, Domenico Siracusa, and Ioannis Tomkos, “A Framework for Dynamic Multi-layer Resource Allocation and Optimization in Application-Centric Networking”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: In an SDN-based network, connection requests can be accommodated according to application requirements. We devise a framework where such requirements drive IP and optical network resource allocation, dynamic optimization, and instantiation through an SDN orchestrator.
- Marco Savi, Federico Pederzolli, Domenico Siracusa, “An Application-Aware Multi-Layer Service Provisioning Algorithm based on Auxiliary Graphs”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: A novel application-aware multi-layer resource allocation algorithm is proposed. We demonstrate that it prevents the violation of application requirements (bandwidth, latency, availability, encryption), while keeping blocking probability lower than an existing algorithm.
- T. Jiménez, V. López, F. Jiménez, O. González, J.P. Fernández, “Techno-economic Analysis of Transmission Technologies in low aggregation Rings of Metropolitan Networks”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: A techno-economic comparison of dark fiber and passive architectures to evolve low aggregation metro rings of 1G is presented. Results demonstrate that there are alternatives more cost-effective than just migrating to 10G.
- Oscar González de Dios, Victor López, Juan Pedro Fernández-Palacios, “Control Plane architectures for Flexi-Grid Networks”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: Elastic optical networks are based on a flexible allocation of the spectrum and configurable transponders. The control architecture is key to unlock their potential. This paper presents the architectural choices, including GMPLS, SDN and TAPI.
- V. López, I. Maor, K. Sethuraman, A. Mayoral, L. Ong, K. Mrówka, F. Marques, A. Sharma, F. Bosisio, O. González de Dios, O. Gerstel, F. Druesedau, R. Vilalta, H. Silva, A. Autenrieth, N. Borges, C. Liou, G. Cazzaniga and J.P. Fernández-Palacios, “E2E Transport API demonstration in hierarchical scenarios”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: We validate the Transport API interoperability with a hierarchical orchestration layer. The demonstration shows the end-to-end provision of connections based on the topology and connectivity services of the Transport API.
- Mohit Chamania, Thomas Szyrkowiec, Michele Santuari, Domenico Siracusa, Achim Autenrieth, Victor López, Pontus Sköldström, and Stéphane Junique, “Intent-Based In-flight Service Encryption in Multi-Layer Transport Networks”, Optical Fiber Communications Conference and Exhibition (OFC), March 2017.
Abstract: We demonstrate multi-layer encrypted service provisioning via the ACINO orchestrator. ACINO combines a novel intent interface with an ONOS-based SDN orchestrator to facilitate encrypted services at IP, Ethernet and optical network layers.
- V. López, J. P. Fernandez-Palacios, T. Szyrkowiec, M. Chamania, “Multi-layer resilience schemes and their control plane support”, 13th International Conference on the Design of Reliable Communication Networks, March 2017.
doi: (none yet)
Abstract: Network operators design and manage IP/MPLS and optical networks on a per-layer basis, to the point that they are run as different business areas within the operator. However, there are clear CAPEX and OPEX savings that network operators can achieve by simplifying the network infrastructure. Moreover, the evolution of optical equipment and the introduction of network programmability are accelerating the adoption of multi-layer schemes in real networks. This paper revisions the planning process considering resilience schemes for IP and optical networks. It also presents an evolutionary view on the control plane and SDN paradigms that enable the support of multi-layer schemes in real networks.
ONDM – The on-line Proceedings are available at the IFIP Digital Library.
- V. López, R. Jimenez, O. Gonzalez de Dios, L.M. Contreras, J.P. Fernandez Palacios, “Open Source Netphony Suite: Enabling Multi-layer Network Programmability”, 21st International Conference on Optical Network Design and Modeling (ONDM), May 2017.
doi: (none yet)
Abstract: Network operators must deal with multi-layer architectures in their production networks. Not so much time ago, network operators were delivering the IP traffic using ATM. ATM protocol was used to aggregate end-user traffic coming from DSL connections. This traffic was transported Synchronous Digital Hierarchy (SDH) as the standard transport technology for fiber-optic transmission systems in backbone networks. There are still networks operating this way. However, current deployments are based on an IP/MPLS layer, either on their own (using dark fiber) or supported by an optical switching network (WDM, OTN, etc.). The IP/MPLS switching and routing are the layers that take advantage of statistical multiplexing and maximize the utilization of the optical links created in the underlying layer.
This multi-layer architecture requires a network programmability layer that enables the control and management of the IP and the optical resources. The advent of distributed protocols to deploy the Internet, lead on many advantages. The main one is the resiliency capability of a network, where each individual node can make their own decisions. On the other hand, a central intelligence enables to have a complete network view to propose optimal solutions to improve the resource utilization. Our proposal of multi-layer network programmability contains a hybrid approach to lever on the advantages of both paradigms. In terms on network protocols, there are to main trends binary versus REST-based. Our view is that binary protocols improve the performance at the low levels on the network, while REST-based APIs enables a faster development and network interoperability.
The Open Source Netphony suite is composed by a GMPLS control plane to emulate the network elements control, a Path Computation Element with active and stateful capabilities, a
Topology Module capable of importing and exporting TE information in different protocols as well as an Application-based Network Operations (ABNO) controller. This framework enables multi-layer programmability for IP and optical networks.
- A. Aguado, V. López, J. Martinez-Mateo, M. Peev, D. Lopez and V. Martin, “GMPLS Network Control Plane Enabling Quantum Encryption in End-to-End Services”, 21st International Conference on Optical Network Design and Modeling (ONDM), May 2017.
doi: (none yet)
Abstract: Quantum key distribution (QKD) is a novel technology that can be seen as a synchronized source of symmetric keys in two separated domains that is immune to any algorithmic cryptanalysis. This technology makes impossible to copy the quantum states exchanged between two endpoints. Therefore, if implemented properly, QKD generates keys of the highest security based on the fundamental laws of quantum physics. No algorithmic advance would force a change of technology, as opposed to current public key cryptographic protocols, that rely on the complexity of certain mathematical problems. These protocols are at risk due to the advances in quantum computing and should be changed. On the other hand, network services are increasingly requesting more flexibility and network resources. One of the most desired capabilities is having higher level of security for the transmission between remote premises.
In this work, we propose a node architecture to provide QKD-enhanced security in end-to-end (E2E) services and analyze the control plane requirements in order to provide such services in transport networks. This work defines and demonstrates for the first time extensions for generalized multi-protocol label switching (GMPLS) networks. Results show how these new services could be integrated in existing operators’ control plane architectures.
- Marco Savi, Ciril Rozic, Chris Matrakidis, Dimitrios Klonidis, Domenico Siracusa, Ioannis Tomkos, “Benefits of Multi-Layer Application-Aware Resource Allocation and Optimization”, European Conference on Network and Communications (EuCNC), June 2017.
doi: (none yet)
Abstract: Internet traffic is generated by a multitude of applications, each one with diverse service requirements in terms of bandwidth, latency, reliability, etc. Today traffic engineering techniques can provide service differentiation at the IP/MPLS layer, but not at the optical layer.
In this paper we propose a framework where application service requirements drive a dynamic multi-layer (IP/MPLS and optical) resource allocation and optimization. We compare by means of simulations such application-aware algorithmic framework with a multi-layer but application-unaware strategy. Results show that the application-aware approach, unlike the application-unaware one, is always able to guarantee the specified service requirements to those applications whose generated traffic is accepted by the network. In addition, the application-aware strategy does not consume more network resources than the application-unaware one, but only requires a network that is more dynamic and responsive.
- Ćiril Rožić, Chris Matrakidis, Dimitrios Klonidis, and Ioannis Tomkos, “Network Primitives Based on Latency and Recovery Time in Orchestrated Multi-layer Networks”, 19th International Conference on Transparent Optical Networks (ICTON), July 2017.
doi: (none yet)
Abstract: Other than merely a bandwidth pipe, current and future network applications will have other requirements such as maximum end-to-end latency and the type of recovery from failure. The added complexity will require a central intelligence such as a software-defined networking (SDN) orchestrator to compute and keep track of the resources allocated to such applications. In such an SDN-orchestrated network, we examine a planning scenario where not all the requirements are known in advance. Instead, they are computed by the network orchestrator and referred to as network primitives. The primitives are then presented to the applications so that the applications know what type of service the network can offer. With our planning algorithm, we show an example of computing the primitives by analysing the guaranteed maximum end-to-end latency and post-failure recovery time.
ICTON – NetOrch WorkShop
- Pontus Sköldström, Stéphane Junique, Abdul Ghafoor, Antonio Marsico, Domenico Siracusa, “DISMI – An intent interface for application-centric transport network services”, 19th International Conference on Transparent Optical Networks (ICTON), July 2017.
doi: (none yet)
Abstract: Application-centric networking is a novel approach to construct transport networks that allows application-specific requirements to be taken into account through the entire service provisioning process: the service offered to each application is differentiated at each layer of the transport network, from IP to optical. This approach replaces the grooming of traffic with different requirements into a shared path in the transport layer, and allows for a finer control and utilization of network resources by network operators.
To make this concept viable, an interface for requesting a connectivity service by applications requires an abstraction with respect to the various underlying network technologies. Interfaces based on the concept of Intents provide such an abstraction: applications can describe what they need from the network (their requirements) rather than how to achieve them. This paper describes the design and implementation of DISMI, the Intent-based North-Bound Interface of a network controller.
- The ACINO concept paper: This paper describes the main concepts that are being developed by the ACINO consortium.
doi: 10.5281/zenodo.49273 (hosted at zenodo.org)
- D. Siracusa, “ACINO: Application-Centric IP/Optical Network Orchestration”, ACINO public presentation (2015).
doi: 10.5281/zenodo.31376 (hosted at zenodo.org)
Abstract: This is a public presentation of the H2020 European project ACINO (Application-Centric IP/Optical Network Orchestration)