Victor Lopez

We present a demonstration of software defined networking (SDN) services utilizing quantum key distribution (QKD) technology, fully integrated with standard telecommunication network connecting production facilities of Telefonica in Madrid. All communications “co-propagate” over the same fiber infrastructure.

This paper reports a technical demonstration showing the use of the ONOS SDN controller for disaggregated transport networks, summarizing the latest developments and results within the Open Networking Foundation (ONF) Open Disaggregated Transport Networks (ODTN) project. The demonstration mainly covers the dynamic provisioning of data connectivity services and advanced automatic failure recovery, both at the control and data plane levels. For the provisioning, we demonstrate the usage of open and standard protocols and interfaces. For the recovery part, we first demonstrate, covering the control plane, how ONOS can behave as a logically centralized controller while using multiple coordinated instances for robustness. We show how the different devices remain under control even in the event of a failure of one of such instances, relying on the ATOMIX framework and the dynamic real-time negotiation of device mastership. For the data plane, we demonstrate the capabilities of the controller to perform automatic restoration of optical services.

Optical communications are the key enabler for the ever-increasing traffic growth as they allow multiplexing many carriers onto a single optical fiber. However, network deployments are becoming more challenging due to the massive bandwidth increments. Indeed, the fiber planning process is a slow, costly and strategic activity for network operators, who must decide where to rent or deploy additional capacity. Depending on the long-term view, the network operator will define a fiber plan which may require high capital expenditure (CAPEX) investments to deploy additional multiple fiber pairs between central offices. During the last few years, C&L-band technologies have evolved to a point where they are now strong candidates to extend the fiber lifetime of these high capacity links. The aim of this article is to present the evolution of C&L-band systems from a network design perspective, covering transmission and optical amplifier capabilities, demand optimization phase, showing a record demonstration of 56.4 Tb/s C&L-band 800 km transmission using commercial C&L-band system technology.

The need of introducing interoperability in the transport network segment has motivated the emergence of several open initiatives and standardization efforts for the development of different interfaces to allow Software Defined Network (SDN) controllers manage and control the network devices. Optical disaggregation in particular aims the introduction of standard device-level interfaces in the optical terminals and line-systems to `open' them from vendor lock-in situations, allowing an interoperable ecosystem in the optical network's transport segment. In this article, it is firstly presented the Software Defined Transport Network (SDTN) architecture, as the control and management framework to build a L0-L3 multi-layer, multi-technology transport network, enabling end-to-end network service delivery. Later, we introduce the partially disaggregated network architecture proposed, including the technical assessment of the topology discovery and resilience service provisioning use cases, by providing a low-level description of the information models employed and the translation between models. To conclude, a proof-of-concept of multi-layer service provisioning over resilient disaggregated multi-vendor testbed is presented, including the results obtained in the experimental demonstration presented in last 2019 Optical Fiber Conference (OFC).

Disaggregation is a trend that is changing the way to architect and to operate networks. This paper presents the different disaggregation alternatives and which are the different elements in a whitebox ecosystem.

Hardware and software disaggregation is a recognized strategy for achieving efficiency and cost reduction within datacentre warehouse. More recently this approach has been applied to high-bandwidth inter-datacentre connectivity at transport layer. Telecom Operators look with great interest at this approach which promises savings that could make the difference in years of ever decreasing margins on revenues. This paper presents and analyses the disaggregation models in the WDM transport layer to replace the established aggregated model based on single vendor systems. Three optical disaggregation models are considered implying different levels of involvement of the Telecom Operator in WDM system design, assembly and integration. The impact on network lifecycle of each model is then analysed with particular reference to the roles of the Operator, the equipment Vendors and the System Integrator. The issue of organizational changes and heavy redefinition of processes is addressed and a comparative techno economic analysis is also proposed.

Network operators have deployed optical transmission systems in their production networks for several years. The transport technology for fiber-optic transmission systems in backbone networks has been a synchronous digital hierarchy. However, network operators started migrating such networks to deploy WDM systems to improve the utilization of the fibers. Network operators can migrate to 100 Gbps solutions that can cope with medium-term bandwidth needs. However, when evolving toward 400 Gbps or 1 Tbps, utilization of the optical spectrum is less efficient if the fixed-grid schemas are maintained. Elastic optical networks (EONs) are based on a flexible allocation of the spectrum and configurable transponders. There is an unprecedented flexibility at the optical layer, thanks to advances in the components to support EONs. To take advantage of such flexibility and unlock the potential of EONs, the control architecture plays a key role. This paper presents the architectural choices, including generalized multiprotocol label switching, path computation element, and software-defined networking using a transport application programming interface. Moreover, this paper presents how the open source Netphony suite enables the validation and testing of all previous control plane architectures for EONs.

The rise of new types of business models with service providers, content providers, and virtual network operators entering in competition with traditional telco operators is reducing revenue margins, making cost-effective provisioning mechanism a necessity. Costly massive overprovisioning needs thus to be replaced by more intelligent dynamic resource allocation. In addition, it is increasingly recognized that many upcoming 5G applications and services will require assured end-to-end quality of service. Operators have thus started to look at network function virtualization and software-defined networks (SDNs) as means to address the challenges of cost-effective and highly dynamic end-to-end provisioning. In this paper we present a test case of an SDN-driven end-to-end service orchestration using a transport API called the control orchestration protocol. Our testbed, interconnecting a core network (within the Telefonica premises in Madrid) and an access network (within the Trinity College of Dublin facilities), demonstrates the possibility to operate sub-second end-to-end capacity reservation, showcasing SDN provisioning across multi-domain networks.

In this Paper, we experimentally demonstrate highly flexible and intelligent interdomain coordinated actions based on adaptive software-defined networking (SDN) orchestration. An advanced multidomain multitechnology testbed is implemented, which consists of a 400-Gb/s variable capacity optical packet switching domain and a Tb/s-class flexi-grid wavelength division multiplexed optical circuit switching domain. The SDN-controllable transponders and the extended transport applications programming interface enable the congestion-aware provisioning of end-to-end real-time services. At the data plane level, different transponders based on orthogonal frequency division multiplexing are employed for inter/intradomain links in order to adaptively provision services with fine granularity. For adaptation, SDN-capable domain-specific optical performance monitors are also introduced. In the control plane, the applications based network operations architecture has been extended and addressed as an adaptive SDN orchestrator.