TERENA Networking Conference 2004, Rhodes, Greece, June Differentiated Optical Services and Optical SLAs Afrodite Sevasti Greek Research and Technology Network (GRNET) TERENA Networking Conference 2004 Rhodes, Greece

TERENA Networking Conference 2004, Rhodes, Greece, June Introduction Until today, offering of network services over the optical infrastructure has been based on a number of layers built over the fibre, at the data link, network and transport layers The burden of offering manageable, reliable transport services is delegated to the IP and optical layers The equipment at the IP layer obtains increasing capabilities, OXCs and DWDM equipment become more ‘intelligent’ The goal: To provide differentiated optical services that better match the user and application needs

TERENA Networking Conference 2004, Rhodes, Greece, June Differentiated optical services Physical layer optical monitoring is critical for connection SLA assurance and fault detection QoS at the optical layer –Multiple physical layer QoS levels (due to linear/non- linear impairments) –BER –Restoration times –Priority and pre-emption Definition of differentiated optical services

TERENA Networking Conference 2004, Rhodes, Greece, June Application needs High level GUNI* services –A generic Grid service interface –Request for optical connectivity –Select a route with certain quality attributes Multi-domain Bandwidth-on-Demand –A single request for a multi-domain environment –Provisioning of a wavelength or logical circuit with QoS –Brokerage and switching * Definition from GGF GHPN Group

TERENA Networking Conference 2004, Rhodes, Greece, June Related activities Optical signal monitoring Quality monitoring in the optical layer (Digital Wrapper) Assignment of quality and operational attributes to optical paths Unified mechanisms for capacity provisioning and protection according to these attributes References to the definition and use of SLAs in the optical layer Co-ordination of quality provided at the IP and optical layers

TERENA Networking Conference 2004, Rhodes, Greece, June The framework The roles of the IP and optical layer are identified and standardized for the purposes of rapid provisioning, routing, monitoring, and efficient restoration –GMPLS –The ASON architecture for automated switching of Optical Channels in Optical Transport Networks The value of providing differentiated optical services increases

TERENA Networking Conference 2004, Rhodes, Greece, June Reference model The general case of IP/MPLS-enabled networks interconnected via an Optical Transport Network (OTN) is our reference architecture. Provisioning of capacity at different levels of granularity (switching fibres, lambdas, wavebands, TDM channels) at the optical layer by the OTN Distinct services offered by the optical layer through qualitative and quantitative attributes Different resilience and availability guarantees Standardized interfaces between users/customers and the OTN Mapping to services at the IP layer

TERENA Networking Conference 2004, Rhodes, Greece, June Reference architecture OIF Architecture, Signalling Working Group, ‘Carrier Optical Services Framework and Associated Requirements for UNI’

TERENA Networking Conference 2004, Rhodes, Greece, June O-SLA A formal representation of –involved entities –resources offered –guarantees and scope of resources’ provisioning with respect to the particular characteristics of optical transmission Use of O-SLAs: –support of differentiated optical services –regulation and viability of service provisioning –a generic framework to apply to the different levels of granularity that GMPLS supports –specify the parameters involved in optical services, so that they can be mapped into signalling protocol parameters for optical connectivity establishment at different scales.

TERENA Networking Conference 2004, Rhodes, Greece, June Case study O-SLA for the provisioning of lightpaths, across the backbone of the OTN, between two SAPs A number of differentiated optical services can be defined based on: –differing characteristics of the optical paths (physical characteristics at the optical layer and others at the data layer) –the protection level of the path –the monitoring level of the path –the transparency/regeneration of the optical signal

TERENA Networking Conference 2004, Rhodes, Greece, June O-SLA structure (1) Service functional specifications –user support mechanisms –maintenance intervals –compensation mechanism in cases of violation Service technical specifications –Lightpath identification, wavelength, type, scope, capacity, interfaces & equipment at end points, provisioning interval –Lightpath availability: Service Availability-SA, Mean Time Between Failures-MTBF, Maximum Time to Restore-MTTR, Time To Provision-TTP

TERENA Networking Conference 2004, Rhodes, Greece, June O-SLA structure (2) Service technical specifications (more..) –Lightpath quality characteristics: Physical characteristics (Optical Power (P), ΟSNR, Q- factor), Data transmission characteristics (BER, ES, SES, support of FEC), Protection characteristics (dedicated, shared protection, unprotected) Regeneration characteristics

TERENA Networking Conference 2004, Rhodes, Greece, June Differentiated optical services

TERENA Networking Conference 2004, Rhodes, Greece, June O-SLAs role O-SLAs are considered as the missing part for the successful deployment of advanced optical services Acting as a regulation mechanism between optical services’ providers and customers A support mechanism for the adoption of a dynamic and distributed optical control plane Providing the required set of parameters for signalling of requests in a uniform manner A business model for the provisioning of optical services in a wide scale, if complemented by pricing principles

TERENA Networking Conference 2004, Rhodes, Greece, June Thank you!