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With the dramatic increase in data traffic envisioned for the next years, operator’s network will be requested to sustain a large amount of data traffic, while at the same time being more flexible easily upgradable and having a lower total cost ownership (TCO). The industry at large is shifting towards SDN architectures, with white-box devices and open source software as building blocks. Such trend allows for further optimization across network layers, packet and optical as an example, with shared infrastructure and control. In this paper, we demonstrate a full end-to-end multi-stage data-center solution, combining leaf-spine control from Trellis, dedicated optical link provisioning by ODTN, and switches and packet optical programmable devices managed by Stratum.Unifying optical and Ethernet capabilities, the Cassini packet-optical transponder acts as a spine in the intra data-center Trellis leaf spine topology, and as the transponder for the DCI inter data-center links.We will describe the implemented architecture, the overall topology, the changes required to achieve the end to end solution and the challenges faced. We then outline the benefits of the proposed solution in terms of resource consumption, end to end optimisation, reliability and resiliency based upon data collected in a physical setup at ONF. Finally, we conclude this paper with future work and proposed optimisations.

We demonstrate end-to-end service provisioning in a fully disaggregated optical network using open software interfaces. The GNPy quality-of-transmission estimator is extended with a YANG-based API. The YANG modeling work builds on the IETF standard schemas, and describes multiple layers of the network at once.

This article 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.

Disaggregation breaks conventional closed systems into components connected by open interfaces. This paper shows the experimental demonstration of service provisioning and partial replacement of network OS in a disaggregated open packet and optical converged network based on open interfaces and open source software.

This demo shows the automatic end-to-end path provisioning over a multi-vendor fully disaggregated Open Line System by Czech Light using the GNPy QoT estimator and Cassini transceiver by the Telecom Infra Project integrated with ONOS.

Use of disaggregated equipment in optical transport networks is emerging as an attractive solution to bring flexibility and break vendor lock-in dependencies. The disaggregation process requires standard protocols and interfaces between the control plane and network equipment. NETCONF has been selected as the standard protocol, and multiple initiatives are currently working on the definition of standard models for each type of data plane device. Different levels of disaggregation of the data plane are under evaluation, and it is still not clear up to which level it will be useful to disaggregate the data plane. The disaggregation of optical networks yielded the development of several controllers based on software-defined networking concepts, providing an environment for creating and deploying networking application on optical networks. Among them, the Open Network Operating System (ONOS) controller features the most active community with the recent establishment of the Open and Disaggregated Transport Network (ODTN) working group, specifically focused on the introduction of required functionality to control and monitor disaggregated transport networks. This paper reports on the state-of-the-art, potentials, and limitations of the ONOS controller applied to disaggregated optical networks with specific focus on the ongoing activities within the ODTN working group. Then, the paper describes a set of experiments performed on a setup including both emulated and real optical devices controlled with ONOS. The performed experiments consider both the establishment of a connectivity service and the recovery of the connectivity in case of failure on the data plane. (C) 2019 Optical Society of America

GNPy is an open source project of the Telecom Infra Project (TIP). It aims at the development of a software library for the abstraction of physical layer data transport, implemented as wavelength division multiplexing (WDM) through open-source code and open APIs, with the purpose of automatizing disaggregated, multi-vendor open optical networks. We first introduce the GNPy library of applications and functionalities, then, we present validation of the GNPy core. The quality-of-transmission estimator (QoT-E) enables a quick and accurate prediction of the unique performance metric in WDM data transport of optical networks: the Generalized Signal-to-Noise Ratio (GSNR). The presented validation experiments show an excellent accuracy in predicting the GSNR compared to the values obtained experimentally. Finally, we present the GNPy integration with the ONOS network OS in a multi-vendor scenario including open reconfigurable add drop multiplexers (ROADMs) and the related validation experiment.

This paper reports a technical demonstration showing the use of the ONOS SDN controller for disaggregated transport networks, within the ODTN Project, covering the provisioning of data connectivity services and demonstrating advanced automatic failure recovery, both at the data and control planes., NO ACK.

State-of-art, potentials and limitations of the ONOS controller applied to disaggregated optical networks are reported. Focus is on the on-going ODTN project. Results of experimental demonstrations are reported to prove the feasibility of proposed approach., © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

ONOS discovers and manages a topology made of Transponders and a dedicated OLS, using standard protocols (NETCONF/RESTCONF) and models (OpenConfig/TAPI). The demo is a joint collaboration, towards production deployment, between 3 operators and 2 equipment vendors., © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The white-box optical ecosystem is considered as the future trend in transport networks, which includes the openness in both software and hardware. The openness in hardware decomposes the equipment into multiple independent components to reduce costs. And the openness in software including general YANG models make all components controllable, which enables fast innovation in the control plane of software-defined networking (SDN). In this paper, an open line architecture (OLA) is proposed to implement the openness and disaggregation to enable white-box optical ecosystem. OLA defines a transport application interface (TAPI) to provide a flexible control of the open line system. To build the physical network, OLA uses the optical equipment developed by different manufacturers that follows specific YANG specifications. And in the control plane, OLA develops a series of drivers and applications to control the calculation, creation, and deletion of optical connectivity service. Finally, the paper shows OLA in use as part of a testbed, which demonstrates the feasibility of building networks consisting of both open and disaggregated hardware.

Software-Defined Networking (SDN) brought an unprecedented flexibility and programmability into computer networks. In order to simplify the management of an SDN network, several high-level languages have been proposed. The Intent Framework provided by Open Network Operating System (ONOS), for example, allows programmers to specify high-level policies without worrying about low-level device details, which are inferred by the controller. In addition, the Intent Framework ensures that the objective is met by transparently re-compiling the intents as a consequence of environment changes (e.g. link failures). In this work we extend the Intent Framework to make it able to both compile multiple intents together and to re-optimize their paths according to the network state based on flow statistics. We present Intent Monitor and Reroute service, a new ONOS module to optimize traffic forwarding of any ONOS applications based on intents, via an external plug&play routing logic with no modifications to ONOS applications at all. Finally we evaluate the benefits by enhancing the ONOS SDN-IP application with an adaptive Robust Traffic Engineering algorithm.

SDN intent-based networking allows programmers to specify high-level policies without worrying about the low-level configurations which are compiled by the controller. Our Intent Monitor and Reroute service (IMR) extends the capabilities of ONOS Intent Framework by allowing to both compile multiple intents together and to re-optimize their paths, according to the network state and their flow statistics, via off-platform applications (OPA). In this demo we show two examples of intent-based ONOS application whose network performance can be improved, with no modifications to their code, exploiting the IMR service.

Identifying factors that may be responsible for regulating the size of animal populations is a cornerstone in understanding population ecology. The main factors that are thought to influence population size are either resources (bottom-up), or predation (top-down), or interspecific competition (parallel). However, there are highly variable and often contradictory results regarding their relative strengths and influence. These varied results are often interpreted as indicating "shifting control" among the three main factors, or a complex, nonlinear relationship among environmental variables, resource availability, predation, and competition. We argue here that there is a "missing link" in our understanding of predator-prey dynamics. We explore whether the landscape-of-fear model can help us clarify the inconsistencies and increase our understanding of the roles, extent, and possible interactions of top-down, bottom-up, and parallel factors on prey population abundance. We propose two main predictions derived from the landscape-of-fear model: (1) for a single species, we suggest that as the makeup of the landscape of fear changes from relatively safe to relatively risky, bottom-up impacts switch from strong to weak as top-down impacts go from weak to strong; (2) for two or more species, interspecific competitive interactions produce various combinations of bottom-up, top-down, and parallel impacts depending on the dominant competing species and whether the landscapes of fear are shared or distinctive among competing species. We contend that these predictions could successfully explain many of the complex and contradictory results of current research. We test some of these predictions based on long-term data for small mammals from the Chihuahuan Desert in the United States, and Mexico. We conclude that the landscape-of-fear model does provide reasonable explanations for many of the reported studies and should be tested further to better understand the effects of bottom-up, top-down, and parallel factors on population dynamics.

Lower-elevation habitats of north-central Chile are characterized by semiarid vegetation that is strongly influenced by rainfall related to El Nino Southern Oscillation (ENSO) events. During the ENSO warm phase (i.e., El Nino), heavy rains occur resulting in small mammal irruptions or ratadas. During prevailing drier periods, pronounced droughts result in reductions in small mammal densities and local extinctions of some species. Within the dominant thorn-scrub habitat of a national park, we identified 2 other habitat types, aguadas (riverine shrublands) and fog-forest patches that serve as refuges for small mammals during dry years. We divide small mammal species of the thorn scrub into 2 groups: core species (Octodon degus, Phyllotis darwini, Abrothrix olivaceus, and Thylamys elegans) maintain populations at all times, whereas opportunistic species (Oligoryzomys longicaudatus and A. longipilis) are present only after rains. The latter group appears to maintain refuge populations in aguadas and fog forests and to opportunistically exploit the thorn scrub when conditions are favorable. Aguadas also may play an important role in the persistence of less-common species, such as Octodon lunatus and Abrocoma bennetti. Despite being small and patchily distributed, aguadas are important for the maintenance of regional biodiversity.

Movements and interactions of Chilean culpeo foxes ( Pseudalopex culpaeus ) were studied in a semi-arid region characterized by periodic droughts. Annual home ranges of adult foxes averaged 3.7 km2 ( SE = 1.1), and home ranges of females were larger than those of males. Human-dominated habitats were included in 85% of estimated home ranges. Home range overlap averaged 27%. Analyses of spatial interactions indicated that two pairs of males shared the same ranges. Temporal interactions suggested a lack of synchrony in individual movement patterns, but foxes were most active during night. Populations of prey and the culpeo fox declined as a consequence of drought.

Partially disaggregated networks require physical layer information to validate end-to-end characterization of WDM signals’ integrity. Transport-API 2.1 includes the photonic-media layer characterization, enabling external wavelength provisioning over an Open Line System. This work presents the first proof-of-concept on a disaggregated multi-vendor testbed with TAPI 2.1., NO ACK.