Overview of South-Bound Interfaces for Software-Defined Optical Networks

In SDN-enabled networks, the control plane and data plane interaction relies on open SouthBound Interfaces (SBIs) so that the SDN controller exercises direct control over the data plane elements. In this paper, we review current initiatives of SBI to control optical components which include ad-hoc extensions of OpenFlow and YANG modelling proposals combined with the NETCONF / RESTCONF protocols. Then we overview different tools and frameworks available for quick prototyping and deployment of software services that are compliant with such interfaces. Finally, we discuss the advantages and drawbacks of the reviewed initiatives considered key enablers for standardized end-to-end network programmability

Traffic allocation strategies in WSS-based dynamic optical networks

Elastic optical networking (EON) is a viable solution to meet future dynamic capacity requirements of Internet service provider and inter-datacenter networks. At the core of EON, wavelength selective switches (WSSs) are applied to individually route optical circuits, while assigning an arbitrary bandwidth to each circuit. Critically, the WSS control scheme and configuration time may delay the creation time of each circuit in the network. In this paper, we first detail the WSS-based optical data-plane implementation of a metropolitan network test-bed. Then, we review a software-defined networking (SDN) application designed to enable dynamic and fast circuit setup. Subsequently, we introduce a WSS logical model that captures the WSS time-sequence and is used to estimate the circuit-setup response time. Then, we present two batch service policies that aim to reduce the circuit-setup response time by bundling multiple WSS reconfiguration steps into a single SDN command. Resulting performance gains are estimated through simulation.Peer ReviewedPostprint (author's final draft

Experimental Validation of Time-Synchronized Operations for Software-Defined Elastic Optical Networks

Elastic optical networks (EON) have been proposed as a solution to efficiently exploit the spectrum resources in the physical layer of optical networks. Moreover, by centralizing legacy generalized multiprotocol label switching control-plane functionalities and providing a global network view, software-defined networking (SDN) enables advanced network programmability valuable to control and configure the technological breakthroughs of EON. In this paper, we review our recent proposal [Optical Fiber Communication Conf., Los Angeles, California, 2017] of time-synchronized operations (TSO) to minimize disruption time during lightpath reassignment in EON. TSO has been recently standardized in SDN, and here we discuss its implementation using NETCONF and OpenFlow in optical networks. Subsequently, we update our analytical model considering an experimental characterization of the WSS operation time. Then, we extend our previous work with an experimental validation of TSO for lightpath reassignment in a five-node metropolitan optical network test-bed. Results validate the convenience of our TSO-based approach against a traditional asynchronous technique given its reduction of disruption time, while both techniques maintain a similar network performance in terms of optical signal-to-noise ratio and optical power budget

On the design of a native Zero-touch 6G architecture

The complexity of envisioned 6G telecommunication networks requires an intrinsically intelligent architecture designed to autonomously adapt to dynamics with end-to-end zero-touch service automation operations. Motivated by this vision, this paper tries to formulate concepts and solution aspects towards designing a native Zero-touch 6G architecture. Our discussion concentrates around three main pillars, i.e. (i) introducing Machine Learning (ML) models in the core design of the 6G architecture as native functions rather than add-on model solutions; (ii) distributing 6G functionality to different components up to the extreme edge; to (iii) leverage technology leaps enabling, e.g., the use of multi-access technologies and peer-topeer communications besides the standard cellular connectivity and other centralised functionalit

VNF Chaining across Multi-PoPs in OSM using Transport API

Management and Network Orchestration (MANO) systems permit simultaneous orchestration of compute and network resources. Here, we experimentally demonstrate the integration of Transport API based WIM with Open Source MANO (OSM), for NFV orchestration over optical networks