Search

The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semidisaggregated metro nodes with compute and storage capabilities, which interface effectively with both 5G access and multi-Tbit/s elastic optical networks in the core. In this paper, we report the automated deployment of 5G services, in particular, a public safety video surveillance use case employing low-latency object detection and tracking using on-camera and on-the-edge analytics. The demonstration features flexible deployment of network slice instances, implemented in terms of European Telecommunications Standards Institute (ETSI) network function virtualization network services. We summarize the key findings in a detailed analysis of end-to-end quality of service, service setup time, and soft-failure detection time. The results show that the round-trip time over an 80 km link is under 800s and the service deployment time is under 180s., Comment: 10 pages

We report the automated deployment of 5G services across a latency-aware, semi- disaggregated, and virtualized metro network. We summarize the key findings in a detailed analysis of end-to-end latency, service setup time, and soft-failure detection time. The research leading to these results has received funding from the EC and BMBF through the METRO-HAUL project (G.A. No. 761727) and OTB-5G+ project (reference No. 16KIS0979K). Peer Reviewed Article signat per 24 autors/es: B. Shariati, Fraunhofer HHI, Germany / J. J. Pedreno-Manresa, ADVA, Germany / A. Dochhan, ADVA, Germany / A. S. Muqaddas, UOB, UK / R. Casellas, CTTC/CERCA, Spain / O. González de Dios, Telefónica, Spain / L. L. Canto, Telefónica, Spain / B. Lent, Qognify GmbH, Germany / J. E. López de Vergara, Naudit HPCN, Spain / S. López-Buedo, Naudit HPCN, Spain / F. J. Moreno, UPCT, Spain / P. Pavón, UPCT, Spain / L. Velasco, UPC, Spain / S. Patri, ADVA, Germany / A. Giorgetti, CNIT, Italy / IEIIT-CNR, F. Cugini CNIT, Italy / A. Sgambelluri, CNIT, Italy / R. Nejabati, UOB, UK / D. Simeonidou, UOB, UK / R.-P. Braun, Deutsche Telekom, Germany / A. Autenrieth, ADVA, Germany / J.-P. Elbers, ADVA, Germany / J. K. Fischer, Fraunhofer HHI, Germany / R. Freund, Fraunhofer HHI, Germany

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 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).

The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) has extended its Recommendations G.694.1 and G.872 to include a new Dense Wavelength Division Multiplexing (DWDM) grid by defining a set of nominal central frequencies, channel spacings, and the concept of the "frequency slot". Corresponding techniques for data-plane connections are known as flexi-grid. Based on the characteristics of flexi-grid defined in G.694.1, RFC 7698 and 7699, this document describes the OSPF-TE extensions in support of GMPLS control of networks that include devices that use the new flexible optical grid.

In a metro network with VIMs orchestrated by an ETSI-OSM instance, and an optical transport controller, we demonstrate optimized service chain provisioning using the open-source Net2Plan tool with interfaces to OSM (new) and transport controller.

This poster was used in the presentation of the demonstration that showcasedthe open-source Net2Plan tool optimally computing and provisioning Service Chain requests with latency considerations by interfacing to an ONOS-controlled metro network and an ETSI-OSM instance orchestrating a set of OpenStack VIMs.

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.

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.

Network operators are willing to provide a range of services in the hope of maximizing their profits: from the highly available connectivity services for key business customers to the unprotected or even best effort services for residential customers. These services are being provided through IP/multiprotocol label switching (MPLS) over wavelength-switched optical networks (WSON) networks. Such multilayer network enables the application of optimal load balancing between the packet and the optical layer, optimizing both the cost of the packet layer and the utilization of the WSON. To provide highly available services, redundant network resources need to be added to the network providing survivability against failures; generally speaking, the higher the survivability degree, the higher both the capital and the operational expenditures (CAPEX and OPEX, respectively) of the network. In this work, we design networks to meet specific availability objectives considering single failures in optical links, IP/MPLS nodes, and optoelectronic ports. The benefits of the designed networks are evaluated from an economic perspective defining costs and revenues models and using Net Present Value as a metric to evaluate future cash flows after an investment. To this end, CAPEX and OPEX, including power consumption and maintenance, and penalties as a consequence of service level agreement breaches are considered. Exhaustive numerical results on several reference network scenarios demonstrate how the value of the network can be maximized by tuning availability objectives.

A common Transport API is proposed for joint cloud/network orchestration, allowing interworking of heterogeneous control planes to provide provisioning/recovery of QoS-aware E2E services. We present its first demonstration in a multi-partner testbed including data-plane monitoring.

The operation of multi-domain and multi-vendor EONscan be achieved by interoperable Sliceable Bandwidth Variable Transponders, a GMPLS/ BGP-LS -based control plane and a planning tool. This paper reports the first full demonstration and validation this end-to-end architecture

This paper presents the challenges and purpose of building the Traffic Engineering Database (TED) to facilitate Software Defined control of an Elastic Optical Network (EON). It explains how a standardized protocol and data model can facilitate this and describes a YANG model that has been developed to represent the TED including the representation of nodes, transponders, links, and available media channels available. This model also represents the established connections (Label Switched Paths - LSPs) between endpoints.

Emerging cloud applications such as real-time data backup, remote desktop, server clustering, etc. require not only more traffic being delivered between datacenters, but also dedicated and application-specific virtual optical network (VON) services to support each application's QoS and SLA level. On the other hand, another requirement is to support end-to-end network service provisioning across multiple VONs comprising different transport (e.g. Flexi-grid DWDM OCS, OPS, etc) and control plane technologies (e.g., centralized OpenFlow or distributed GMPLS). This paper presents the preliminary architecture of the network virtualization, control and orchestration layers proposed in the STRAUSS project.

We report the experimental testbed evaluation of connectivity provisioning in which OpenFlow and GMPLS control planes interwork by means of an orchestrating stateful PCE. The hierarchical nature of the PCE allows seamless multi-domain operation.

Optical networks and Internet Protocol/Multi-Protocol Label Switching (IP/MPLS) based networks have been traditionally designed and operated by separate departments of network operators. Likewise, both layers have always represented different business areas for system providers, which maintain different product lines for each of them. However, network operators have an IP/MPLS over WDM architecture. The main drivers for this unique transport network are the cost savings achieved by simplifying the network infrastructure. Thanks to the advent of reconfigurable optical equipment and a multi-layer control plane, 1+1 node protection at the IP layer in each location is no longer required. This work compares two resilience strategies on multi-layer network dimensioning: dual-plane protection and a multi-layer shared backup router (MLSBR). Based on the results of this paper, a MLSBR provides a significant reduction (up to 24%) on the required IP equipment in comparison with the IP protection approach.

ABNO architecture is proposed in IETF as a framework which enables network automation and programmability thanks to the utilization of standard protocols and components. This work not only justifies the architecture but also presents the first experimental demonstration.

A Network Operating System (NetOS) is a novel paradigm for developing a next-generation network management and operation platform. As we shall describe, NetOS not only goes far beyond the SDN concepts but also constitutes a fundamental enabler for NFV. © 2014 OSA.

Metro and core networks have been traditionally designed and managed by different departments within network operators. Moreover, even in the cases where both metro and core networks are based on the same technology, e.g. MPLS, services need to be provided separately per domain. This historic separation is now being questioned in light of the potential cost efficiency and lower time-to-market that an end-to-end service provisioning could bring, especially in a cloud ready context, where the traffic demands are less predictable and fast provisioning is needed. This paper presents the drivers, enablers and challenges for an end-to-end service provisioning, in which a multi-layer IP/MPLS over WDM core and MPLS based metro networks are coordinated to support dynamic service provisioning. The feasibility of the end-to-end service provisioning is demonstrated in an experimental activity using commercial IP/MPLS routers, optical nodes and a network controller triggering control plane mechanisms.

In the H-PCE architecture the mechanism to build the Traffic Engineering Database of the Parent PCE is not defined. This work validates the use of BGP-LS to feed the TED and compares two algorithms that use different amount of information.

Orchestration between multiple layers requires a standard architecture to enable such coordination in multi-vendor scenarios. This work proposes an architecture to solve multi-layer orchestration and experimentally validates topology dissemination in a multi-vendor environment.

The Path Computation Element (PCE) is positioned nowadays as one of the solutions that almost every carrier will eventually deploy. The PCE architecture as well as a number of components, including the PCE Communication Protocol (PCEP), have been standardized by the IETF. However, a number of challenges remain to be solved on its way from standards to deployment. In particular, the existing proposals for multilayer path computation within the PCE framework need to be further developed and tested, before considering their possible integration into operational networks. This is especially true for the interoperability of the various PCE implementations and the extensions such as the Virtual Network Topology Manager (VNTM) which cannot be taken for granted. This paper presents a functional implementation of coordinated computation of multilayer paths supported through inter-layer PCE communication, where one PCE is developed by industry and the other as an open-source effort. To this end, we consider an IP/MPLS network deployed over a Wavelength Switched Optical Network (WSON), each of which deploying its own PCE, in an attempt to create an inter-operable multilayer solution. We discuss the key challenges that the research community will face in this area, which in turn will drive a considerable part of the upcoming efforts in terms of standardization.

A temporary resource reservation mechanism can enhance the performance of a stateless PCE in situations when the TED might not be up-to-date. This paper examines the benefits of such a mechanism by means of simulation.

This paper shows the CAPEX benefits of an IP over reconfigurable WDM network architecture, which combines most of the benefits of IP Offloading theory while entailing a minimal impact in current IP core networks design.

This paper provides an overview of the recent developments in research and the IETF standardization body on using a path computation element in complex telecom networking scenarios such as the multi-layer and multi-domain cases. Implications on the control plane when using such element are addressed as well as the required protocol extensions. The emerging impairment-aware routing and wavelength assignment problem is extensively treated for networks using lightpaths.

This paper was published in Journal of Lightwave Technology and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the IEEE website: http://dx.doi.org/10.1109/JLT.2007.901325. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law., Nowadays, network operators are steadily deploying optical circuit switching (OCS) equipment in their metropolitan networks in order to cope with traffic increase and, most importantly, in order to reduce capital expenditures and operational expenditures of existing active technologies. On the other hand, optical burst switching (OBS) technology is expected to become mature in the medium term, and it may be used as an alternative to current OCS networks due to its potential advantages in terms of bandwidth allocation granularity. While OBS is being extensively studied in the literature, little attention has been paid in conducting a comparative analysis of OBS versus OCS, especially concerning cost analysis. In this paper, we provide a comparative analysis of OBS versus OCS as an evolutionary technology for all-optical rings in the metropolitan-access network. This paper is specifically targeted toward optimizing the number of optoelectronic receivers and wavelengths with real traffic matrices from the metropolitan rings in Madrid, Spain. Such matrices also include traffic projections of foreseeable broadband services, which are based on a market analysis from the largest operator in Spain. Our findings show that OCS might be more efficient than OBS in the metro-access segment, which is characterized by a highly centralized traffic pattern. However, the more distributed the traffic is, the more efficient the OBS is as well. Consequently, OBS might be better suited to metro-core networks, which show a more distributed and dynamic traffic pattern., The authors would like to thank the e-Photon/ONe+ network of excellence

The control of multidomain elastic optical networks (EONs) is possible by combining Hierarchical Path Computation Element (H-PCE)-based computation, Border Gateway Protocol with Extensions for Traffic Engineering Link State Information (BGP-LS) topology discovery, remote instantiation via Path Computation Element Communication Protocol (PCEP), and signaling via Resource Reservation Protocol with Extensions for Traffic Engineering (RSVP-TE). Two evolutionary architectures are considered, one based on stateless H-PCE, PCEP instantiation, and end-to-end RSVP-TE signaling (SL-E2E), and a second one based on stateful active H-PCE with per-domain instantiation and stitching. This paper presents the first multiplatform demonstration that fully validates both control architectures achieving multiprotocol interoperability. SL-E2E leads to slightly faster provisioning but needs to keep the state of the stitching of the end-to-end label-switched paths in the parent PCE.

IST project NOBEL2 results on resilience strategies for next-generation optical transport networks are presented, paving the way towards cost-effective, scalable and easy-to-maintain multi-service network architectures.

The first experimental demonstrator of 46-108Gbps discrete-multi-tone (DMT) fixed-length variable capacity OPS over programmable, flexi-grid elastic optical path network (EON), orchestrated via multiple OpenFlow controllers in the framework of SDN is presented.

This is the author’s version of a work that was accepted for publication in Optical Switching and Networking. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Optical Switching and Networking, 4, 1 (2007) DOI: 10.1016/j.osn.2006.10.003, This paper presents a summary of Optical Burst Switching (OBS) research within the VI framework program e-Photon/ONe network of excellence. The paper includes network aspects such as routing techniques, resilience and contention resolution, together with burst switch architectures. On the other hand, we also discuss traffic analysis issues, Quality of Service (QoS) schemes, TCP/IP over OBS and physical layer aspects for OBS., This work was partly funded by the e-Photon/ONe Network of Excellence