Daniel King

In-operation network planning

Current transport networks are statically configured and managed, because they experience a rather limited traffic dynamicity. As a result, long planning cycles are used to upgrade the network and prepare it for the next planning period. Aimed at guaranteeing that the network can support the forecast traffic and deal with failure scenarios, spare capacity is usually installed, thus increasing network expenditures. Moreover, results from network capacity planning are manually deployed in the network, which limits the network agility. In this article, we propose a control and management architecture to allow the network to be dynamically operated. Employing those dynamicity capabilities, the network can be reconfigured and reoptimized in response to traffic changes in an automatic fashion; hence, the resource overprovisioning can be minimized and overall network costs reduced.

Network service orchestration standardization

Network services underpin operator revenues, and value-added services provide income beyond core (voice and data) infrastructure capability. Today, operators face multiple challenges: a need to innovate and offer a wider choice of value-added services, whilst increasing network scale, bandwidth and flexibility. They must also reduce operational costs, and deploy services far faster - in minutes rather than days or weeks.In the recent years, the network community, motivated by the aforementioned challenges, has developed production network architectures and seeded technologies, like Software Defined Networking, Application-based Network Operations and Network Function Virtualization. These technologies enhance the highly desired properties for elasticity, agility and cost-effectiveness in the operator environment. A key requirement to fully exploit the benefits of these new architectures and technologies is a fundamental shift in management and control of resources, and the ability to orchestrate the network infrastructure: coordinate the instantiation of high-level network services across different technological domains and automate service deployment and re-optimization.This paper surveys existing standardization efforts for the orchestration - automation, coordination, and management - of complex set of network and function resources (both physical and virtual), and highlights the various enabling technologies, strengths and weaknesses, adoption challenges for operators, and areas where further research is required. A survey of the standardization efforts for network service orchestration.Develeop an orchestration architecture and a taxonomy of technologies.A systematic review of standardization across SDOs.Future direction for automated and converged orchestration standards.This is the first survey to blend service orchestration for SDN and NFV.

IDEALIST control plane architecture for multi-domain flexi-grid optical networks

The IDEALIST (Industry-Driven Elastic and Adaptive Lambda Infrastructure for Service and Transport Networks) project has designed and implemented a Generalized Multi Protocol Label Switching (GMPLS) control plane for flexi-grid optical Dense Wavelength Division Multiplexing (DWDM) networks, providing significant input for IETF standardization. The control plane supports delegating the path computation function to dedicated Path Computation Elements (PCE), notably when justified by the limitations of the optical technology. This paper objectives are two-fold: to provide an overview of the major issues and challenges of the extension of such GMPLS/PCE control plane for multi-domain networks and to summarize the main architectural, functional and protocol choices. The architecture is based on the concept of domain topology abstraction and on the use of a stateful hierarchical PCE (H-PCE). The parent PCE coordinates the selection of domains and the multidomain provisioning using an abstracted view, and delegates the actual computation and actual intra-domain provisioning to the corresponding children PCEs. The parent abstracted view is constructed using the BGP-LS protocol (Border Gateway Protocol with Link State extensions) and end to end connectivity is obtained by concatenating Label Switched Paths (LSPs) segments, which are set up independently by the underlying GMPLS control plane at each domain.

MPLS-TP linear protection for ITU-T and IETF

The MPLS Transport Profile (MPLS-TP) is a framework for the construction and operation of reliable packet-switched transport networks based on the architectures for MPLS and Pseudowires. Its development has been shared between the IETF, where the MPLS expertise resides, and the ITU-T, with its historic understanding of transport networks. MPLS-TP adds two significant features to the MPLS toolkit: Operations, Administration, and Maintenance (OAM), and linear protection switching. Unlike OAM, which resulted in two application specific and incompatible standards being approved at the World Telecommunication Standardization Assembly (WTSA) in November 2012, the MPLS-TP linear protection specification has resulted in a single unified solution that has been published in IETF RFCs and in ITU-T Recommendation G.8131. This article outlines the novel concepts and operation principles of the unified MPLS-TP linear protection switching mechanism and discusses how it differs from pre-existing solutions. In addition, the issues of compatibility with pre-existing solutions and the applicability to other network topologies are discussed.

Path Computation Architectures Overview in Multi-Domain Optical Networks Based on ITU-T ASON and IETF PCE

The capability to compute end-to-end paths across multiple optical domains, or inter-domain path computation, is an essential requirement in the continued evolution of todays optical transport networks. The key technologies and network conditions required for end-to-end multi- domain services exist, but, they are not ideal and will require further development to meet network operator requirements. This paper describes the enabling International Telecommunication Union (ITU-T) and Internet Engineering Task Force (IETF) architectures and technologies that can be combined to achieve path computation for end-to-end connectivity in multi-domain optical transport environments. This paper also outlines the technical areas that require continued development to enhance existing path computation techniques to provide paths that cross multi-domain optical networks.

The role of SDN and NFV for flexible optical networks: Current status, challenges and opportunities

Todays optical transport domains are typically built using fixed grid technology. They are statically configured and operationally intensive to manage, lacking the capability for dynamic services and elastic bandwidth. Recent research has established the benefits of flexible grid technologies for optical switching allowing dynamic and elastic management of the available bandwidth resources. Combined with Software Defined Networks (SDN) control principles and Network Functions Virtualization (NFV) infrastructure, we have the potential to fundamentally change the way we build, deploy and control network applications built on top of flexible optical networks. This paper outlines the current Internet Engineering Task Force (IETF) developments for standardizing flexible grid optical technologies, and discusses how software-defined and function virtualisation principles have and will continue to provide the key capabilities to further enable flexible optical switching technologies to control and deliver NFV-based services and applications. It addition it describes the benefits for the virtual Content Distribution Network (vCDN) use case when combined with an IETFs SDN framework Application-Based Network Operations (ABNO). Finally, we highlight the research opportunities for furthering the application of SDN and NFV for control and orchestration of flexible optical networks using the IETF ABNO-based framework.

OpenCache: A software-defined content caching platform

Network operators recognise that Content Delivery Networks are essential for meeting user Internet application and content demands. The infrastructure must be tightly integrated to provide request routing, content caching, load balancing, scalability and reliability, whilst minimising deployment time and complexity. A major step towards achieving these goals is to embrace recent Software Defined Network and Network Function Virtualisation objectives and design principles. This paper outlines the OpenCache API; an interface used to define the behaviour and operation of an SDN-based content delivery platform in real-time. We demonstrate the applicability and effectiveness of such an API by implementing load-balancing and fail-over functionalities as part of an experimental deployment.

Prospects for software defined networking and network function virtualization in media and broadcast

Software Defined Networking (SDN) and Network Function Virtualization (NFV) provide an alluring vision of how to transform broadcast, contribution and content distribution networks. In our laboratory we assembled a multi-vendor, multi-layer media network environment that used SDN controllers and NFV-based applications to schedule, coordinate, and control media flows across broadcast and contribution network infrastructure. — This paper will share our experiences of investigating, designing and experimenting in order to build the next generation broadcast and contribution network. We will describe our experience of dynamic workflow automation of high-bandwidth broadcast and media services across multi-layered optical network environment using SDN-based technologies for programmatic forwarding plane control and orchestration of key network functions hosted on virtual machines. Finally, we will outline the prospects for the future of how packet and optical technologies might continue to scale to support the transport of increasingly growing broadcast media.

Adaptive network manager: Coordinating operations in flex-grid networks

Transport networks provide reliable delivery of data between two end points. Todays most advanced transport networks are based on Wavelength Switching Optical Networks (WSON) and offer connections of 10Gbps up to 100Gbps. However, a significant disadvantage of WSON is the rigid bandwidth granularity because only single, large chunks of bandwidth can be assigned matching the available fixed wavelengths resulting in considerable waste of network resources. Elastic Optical Networks (EON) provides spectrum-efficient and scalable transport by introducing flexible granular grooming in the optical frequency domain. EON provides arbitrary contiguous concatenation of optical spectrum that allows creation of custom-sized bandwidth. The allocation is performed according to the traffic volume or user request in a highly spectrum-efficient and scalable manner. The Adaptive Network Manager (ANM) concept appears as a necessity for operators to dynamically configure their infrastructure based on user requirements and network conditions. This work introduces the ANM and defines ANM use cases, and its requirements, and proposes an architecture for ANM that is aligned with solutions being developed by the industry.

Baguette: Towards End-to-End Service Orchestration in Heterogeneous Networks

Network services are the key mechanism for operators to introduce intelligence and generate profit from their infrastructures. The growth of the number of network users and the stricter application network requirements have highlighted a number of challenges in orchestrating services using existing production management and configuration protocols and mechanisms. Recent networking paradigms like Software Defined Networking (SDN) and Network Function Virtualization (NFV), provide a set of novel control and management interfaces that enable unprecedented automation, flexibility and openness capabilities in operator infrastructure management. This paper presents Baguette, a novel and open service orchestration framework for operators. Baguette supports a wide range of network technologies, namely optical and wired Ethernet technologies, and allows service providers to automate the deployment and dynamic re-optimization of network services. We present the design of the orchestrator and elaborate on the integration of Baguette with existing low-level network and cloud management frameworks.