CaON

Converged and Optical Networks Cluster

FP7 Future Networks

White paper

Date: 27/02/2012

Chairs:

Prof. DimitraSimeonidou ()

Sergi Figuerola ()

Co-chairs:

Juan Fernández Palacios ()

Andrea Di Giglio ()

List of Contributors

Contributors / Company/institute / e.mail address
Dimitra Simeonidou / UEssex /
Sergi Figuerola / I2CAT /
Juan F. Palacios / TID /
Andrea Di Giglio / Telecom Italy /
Anna Tzanakaki / AIT /
Nicola Ciulli / Nextworks /
Andrea Bianco / Polito /
Reza Nejabati / UEssex /
GeoregousZerva / UEssex /
Mikhail Popov / Acreo /
Josep Prat / UPC /
Xavier Masip / UPC /
Marcelo Yannucci / UPC /
Raul Muñoz / CTTC /
Ramon Caselles / CTTC /
Marcos….. / Acreo /
Joan A. García-Espín / I2CAT /
Tania Vivero Palmer / TID

List of Acronyms

1

API / Application Programming Interface
CaON / Converged and Optical Networks
CapEx / Capital Expenditures
CD / Chromatic Dispersion
CDN / Content Delivery Network
DC / Data Centre
E-NNI / External network-to-network Interface
EPON / Ethernet Passive Optical Network
FSAN / Full Service Access Network
GMPLS / Generalized Multi-Protocol Label Switching
GPON / Gigabit Passive Optical Network
IaaS / Infrastructure as a Service
ICT / Information and Communications Technology
IETF / Internet Engineering Task Force
IMF / Information Modelling Framework
LTE / Long Term Evolution
MAN / Metropolitan Area Network
MIMO / Multiple-Input and Multiple-Output
MTOSI / Multi-Technology Operations System Interface
NDL / Network Description Language
NIPS UNI / Network + IT Provisioning Service User-to-Network Interface
NMS / Network Management System
OAM / Operation and Administration and Management
OBS / Optical Burst Switching –or– Operational Business Support
OFDMA
PON / Orthogonal Frequency Division Multiple Access Passive Optical Network
OLT / Optical Line Termination
ONU / Optical Network Unit
OOFDM / Optical Orthogonal Frequency Division Multiplexing
OpEx / Operational Expenditures
OPS / Optical Packet Switching
OSS / Operation and Support System
PCE / Patch Computation Element
PLI / Physical Layer Impairment
POF
(SI-POF) / (Step-Index) Plastic over Fibre
RACS / Resource and Admission Control Sub-System
RDF / Resource Description Framework
RN / Remote Node
ROADM / reconfigurable optical add-drop multiplexer
RWTA / Routing Wavelength and Time slot Assignment
SDN / Software Defined Networks
SDK / Software Development Kit
SLA / Service Level Agreement
SOA / Service-Oriented Architectures
TSON / Time-Shared Optical Network
udWDM / Ultra Dense Wavelength Division Multiplexing
UHD / Ultra High Definition
UPnP-QoS / Universal Plug and Play Quality of Service
VXDL / Virtual eXecution Description Language
WSON / Wavelength Switched Optical Network

1

Index

1.Introduction

2.Justification/Rationale

3.Technologies enabling the CaON reference model

3.1.Optical network IT convergence

3.2.Optical network virtualization

3.3.Cross-layer considerations

4.CaON Physical technologies in support of FI services

4.1.Core

4.2.Metro

4.3.Flexible and Elastic Core/Metro optical Networks

4.4.Access

4.5.Access/metro and in-building/home networks

5.CaON Control and Management Plane Technologies in Support of Future Internet Services

5.1.Control plane evolution

5.2.Management plane evolution: From rigidness to programmable management

5.3.Evolution in Optical Networks towards cognitive and self-managed networks and its impact on control and management planes

6.Energy efficiency and Green networking

7.Standardisation

7.1.Optical data plane technology

7.2.Optical control plane

7.3.IT and network integration

8.References

Executive Summary

TBD….

1.Introduction

This white paper exposes the key role that optical networks and its associated infrastructures have towards the success of Future Internet. It takes into consideration technical inputs gathered across different projects composing the FP7 CaON cluster[i], and presents the main trends for optical networks research. These research topics are positioned with relevance to the CaON reference model. This is a referencearchitecture modelagreed among the projects belonging to the cluster and reflects the high level architecture that the CaONcluster foreseesfor the Future Internet.This positioning paper aims at complementing the relevant Photonics 21 and Net!workswhite papers.

This positioning paper is structured as follows: it presents the rationale and trends of Future Internet with regards to optical networks, followed by an overview of enabling technologies for the CaON reference model. After presenting the reference model, the physical technologies with their control and management planes are presented. Moreover, some standardisation strategies are identified, together with the impact of energy efficiency and green IT.

2.Justification/Rationale

Optical infrastructure is the physical substrate that historically has enabled the wide deployment of the Internet and continues to be critical for Future Internet. Flexibility, transparency, capacity, low cost per bit, isolation capabilities and advanced provisioning services make optical infrastructure a key enabler for the evolution and convergence of Future Networks..

The Internet has become one of the basic infrastructures that support the World economy nowadays. In fact, networked computingdevices are proliferating rapidly, supporting new types of services, usages and applications: from wireless sensor networks and new optical network technologies to cloud computing, high-end mobile devices supporting high definition media, high performance computers, peer-to-peer networks and a never ending list of platforms and applications. In the last years there has been a trend (and a requirement) for a convergence of the different networked platforms towards a unifying architecture or reference model for seamless end-to-end communication regardless of the device technology and access/metro/core infrastructure domain segmentation. Particularly, some of these different areas, technologies and innovations at the infrastructure level are going to generate a big impact on the evolution of our society. We can establish an initial differentiation between mid-term and long-term approaches. Being the former the convergence of IT & Telco towards cloud computing, with optimisation of interactions between applications providers, resource, service consumers, network operators and infrastructure providers (with SLA mapping); and the later the definition of new architectures as key area of basic research for the coming years with new technologies at the core, metro and access networks.

Emerging applications are entering the arena of telco services with an unprecedented end-user acceptance. Similarly than the Internet has settled into daily life, Cloud Computing is making its way towards becoming the invisible stratus on which companies base their IT processes and users get their content. From the network perspective, it means understanding traffic demands to adopt the technology combination that best fits its support.Video and Cloud Computing demands are stressing the networkas never experienced during the past decade, and will be the drivers of the network infrastructure evolution roadmap (fig. 1).

Figure 1: Global consumer Internet traffic Figure 2: VM and physical server shipment evolution

Moreover, proclaims of the advantages of Virtualized resources over Physical ones are well known and can be found wherever in the Internet, e.g. resource usage optimization [1], saves on energy consumption [2].The introduction of Cloud Services in a massive fashion entails new constraints that may be convergent with the ones that come from the distribution of contents among the network. Here is where the core network will adopt a key role in Cloud service provisioning. It may provide:

  • Connectivity capabilities for residential and business customers towards the DCs and the external Internet.
  • Highly reliable, low delay and high bandwidth demanding interconnections between the cloud/CDN DCs themselves.

Due to the wide range of final services andhigh traffic demand between users and providers Cloud and DCsinfrastructures will have to adapt to unprecedented levels of elasticity and contain unpredictability. However, current core and metro networks are not ready for these new traffic demands and behaviour.Core transport is characterized by a variety of networks, technologies and providers. Metro networks, in charge of aggregatingtraffic from access nodes (e.g. DSLAM, OLTs, Nodes B, corporate, etc), are typically based on Ethernet Metropolitan Area Networksolutions fromdifferent providers. Within this scenario, core network may make up a bottleneck. Strategically, core, metro and access networks operation and capacity should be adapted to new services demand, in contrast to current core architectures where the adaption to new services is mainly covered by over-dimensioning and over-provisioning(i.e. over-dimensioning in LANs and over-provisioning in WAN). To successfully respond to the traffic demands presented in the previous point, optical networks must support:

  • An extensive amount of requests from DCs while the rest of traffic remains unaffected.
  • Bandwidthand QoS assurance between end users andDCs (i.e. real time applications).
  • QoS enhancement (via better use of existing network and data center).
  • Flexible networking services enabling on demand fast data transfers.
  • High capacity and scalability
  • Costs optimization (DC and network).
  • Responsiveness to quickly changing demands and infrastructure customisation.
  • Enhanced service resilience (cooperative recovery techniques).

The inadequacy of the current core architecture to fulfil these requirements (Error! Reference source not found.)evidences the need of the conception of a new architecture capable to enable flexible connectivity services, specially adapted to new requirements with reasonable costs.A key challenge for optical networks is the capability to perform automated and flexible connectivity services between endusers and DCs. This network model is conceived to:

  • Accelerate service provisioning and performance monitoring.
  • Enable on demand connectivity configurations (e.g. bandwidth) toend users.
  • Optimize both converged infrastructure costs and energy footprint (e.g. consumption, carbon footprint)Guarantee the required QoS (e.g delay, jitter…) for real time and video services.

Key requirements for a Cloud enabled network
Connectivity Service / Cost/ bit / Guaran-teed BW / Guaran-teed QoS / Range / Flexible BW / Automated Operation / BW beyond 10Gbps
Current Core Arch. / Internet (L3) / LOW / NO / NO / Global / YES / YES / NO
Static IP VPN / HIGH / YES / YES / Global / NO / NO / NO
Static L2 VPN / MED / YES / YES / MAN / NO / NO / NO
Cloud Enabled Network / Flexible Connec-tivity Services / LOW / YES / YES / Global / YES / YES / YES

Table 1

3.Technologies enabling theCaONreference model

The CaON reference model (figure 3)presents a multi-dimensional, layered architecture for the convergence of optical networks andfuture technologies and services.The main conclusion from the CaON cluster is that theICTconvergence playsa key roleat the infrastructure level. This convergence is the basisto bring innovation at upper layers and enable a real and powerful cloud networked infrastructure deployment where the optical network can dynamically react to different and new applications behaviour.

This is a bottom-up reference model, where the infrastructure and provisioning layers, together with cross-layer SLA and management, are the key focus for future research trends within the CaON cluster community.

The physical infrastructure layer covers from the core to the access optical network. Within the infrastructure layer we can identify the virtualisation capability. It provides a more flexible way to deal with infrastructure resource utilization by overcoming the multilayer and current network segmentation, and a whole new set of functionalities (flexibility and new dynamic provisioning services) that enables the convergence of optical infrastructures to support cloud services delivery. Moreover, it facilitates the emergence of new business models by enabling the entrance of new players. However, with regards to virtualisationthere are still many research topics that need to be addressed and further discussed (i.e. how isolation is managed and the impact that non-linear effects have on it).

Figure 3: CaON reference model

More particularly, the provisioning layer is focused on a control plane architecture that may provide a new set of functionalities at the infrastructure level, enabling:

  • Scalable multi-domain and multi-technology scenarios with open control planes and enhanced UNI’s interfaces.
  • Automated end-to-end service provisioning and monitoring between different network segments and operators with coordinated management planes.
  • Network resources optimization by integrated control of different network technologies (e.g. IP and optical).
  • Network/IT resources optimization by means of cross-stratum interworking mechanisms.
  • Operation over virtual instances of the network infrastructure.
  • Convergence of analogueanddigital communications unifying heterogeneous technologies.
  • Unified OAM mechanisms able to operate in a complex behaviour (multi-technology, multi-domain and multi-carrier).

On top of the provisioning layer there is the service layer. It establishes the link between the network infrastructure and the applications (cloud service requirements). This is the layer where the network exposes its services, resources and capabilities, enabling:

  • Application to network interface: this interface may enable the request of new and advanced services fromthe cloud to the network control plane.
  • On demand services provisioning with advancedre-planning [jage1]functionalities.
  • Co-advertisement, co-planning, co-composition and co-provisioning of any type of network resource and IT services (i.e. connectivity + IT resources at the end-points coordinated in a single, optimal procedure)
  • Enhanced Traffic Engineering framework for resource optimization, advance allocation and energy consumption, in support of energy-efficiency.
  • Implementation of network prototypes comprising the innovative data and control plane solutions designed along the projects, in particular, pre-commercial software (control plane, network-service interworking…) and hardwareprototypes (sub-wavelength switching, multi-granular nodes, etc).
  • Industrial exploitation: Accelerated uptake of the future networks and service infrastructures enabling increased access capacity and flexibility, as well as cost and power consumption minimization for intensive bandwidth consuming applications and cloud services.

At the cross-layer level, the CaON reference model considers two vertical layers. These are the SLA layer, another interesting topic within the convergence approach,and the Management layer. The former takes into consideration the mapping of the SLA requirements from the application layer down to the infrastructure (virtual) resources. The later is in charge of extending management functionsacross the different sets of resources, including virtual ones, and layers in coordination with the control plane and the provisioning layer.

3.1.Optical network IT convergence

The IT andTelco convergence mainly deals with dynamic flexible behaviour of network infrastructures and the integration of their operation and management processes with the IT infrastructures systems and services. However, the end challenge is on the capability to provide application-aware infrastructure through a new and well-defined set of Network/Infrastructure Service Interfaces. Actually, the dynamicity of those applications and collaborative group environments require that such infrastructures are provisioned on demand and capable of being dynamically (re-) configured. Dynamicity is also necessary to optimize the resource usage and reduce the service provisioning time, which so far is still slow and manual compared to application service needs. In fact, these applications will continue to evolve in features, size and amount of customers, as the associated business requirements change. Thus, the availability, performance, security and cost-effectiveness of application-aware infrastructure remain critical, as they support business decisions and data in a fast-paced, economy-driven environment.

Current provisioning services over hybrid infrastructures (managed networks and IT), composed of both IT resources (i.e. compute and storage) and high capacity optical networks, need unified management and provisioning procedures. This means the usage of cognitive, flexible, elastic and adaptive technologies for core and metro optical networks, with dynamic control plane functionalitiesand programmability features, as those in Software Defined Networks (SDN),for the whole integration with the DCnetwork infrastructures is a must. SDN gives owners and operators of networks better control over their networks, allowing them to optimize network behaviour to best serve their and their users needs. However, current disjoint evolution has ended up with totally decoupled solutions for each type of resource and infrastructure, those under the network operator domain and those under the DC administrator domain. Therefore, there is a key technical challenge towards this ICT convergence and hence, be able to optimize the (i) infrastructure sharing for lowering OpEx/CapExcosts, and (ii) the (dynamic) services and applications deployed on top of these hybrid infrastructures with energy efficiency considerations. In this context, convergence also considers the trend toward infrastructure resource virtualisation and federation, thus providing full flexibility at the infrastructure level.

3.2.1.Management and control planes convergence

Management and control planes convergence is required as a must for future-proof, and Internet-scale enterprise applications. Distributed applications, consuming resources spread all over the world, require DCs and network core/metro convergence in order to optimize the service workflow and overall performance for cloud computing. Dynamic provisioning of one type of infrastructure resources only considers part of the problem, and typically leads to a waste of resources due to over-provisioning[jage2], mostly in networks, and sharing limitations in all kinds of resource usage. It must be noted that, as time goes by, hardware is increasing its power (switching, computing, storage, etc.) and embedding degree, which means that a higher control in granularity is needed too, both at the network and IT level. In the end, the challenge is on providing a common and transparent infrastructure able to integrate different technologies and services, where virtualisation is not the end solution but an adequate technique for overcoming many limitations.Some future research considerations are:

  • Keep IT/Telco converged infrastructure provisioning service (IaaS) time at a minimum.
  • Unified and converged resource description languages andframeworks.
  • Multi-granular, cognitive, elastic, flexible and adaptive optical networks (e.g. hardwareconfiguration).
  • Isolation and flexibility of circuit-oriented networks (using resource virtualisation).
  • Definition of the impact of these new technologies on legacy business models.
  • Inter-administrative domain issues between networks and DCs.
  • Non-standard service provisioning (alien wavelength services).
  • Carrier grade cloud and DC integrated infrastructure services.

3.2.Optical network virtualization

As commented, current physical infrastructures are mainly constrained by the amount of resources they can deal with, and this has to be solved[jage3]. New infrastructures will be composed of heterogeneous resources that allow the delivery of any type of services between different nodes. Resources like network elements, connectivity, storage and computation are those that take part as core elements of the physical substrate and enable the creation of cloud infrastructures. The challenge, however, is on the level of flexibility, optimization and transparency to deliver a service and the need to map the abstraction (virtual representation) of physical resources and network topologies with the applications and service requirements. No matter what the infrastructure is, it would be homogeneously controlled and managed to deliver any requested service. Virtualisation will help on overcoming the multilayer and current network segmentation. Thus, at this point is where network virtualisation will bring the envisaged flexibility for the network infrastructures.