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SLA/SLS in service creation
G. Cortese CADENUS Project 25.01.01
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Agenda

• SLA in CADENUS overview
• SLA/ Service Model
• Techniques to achieve SLA-based service creation

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SLA in CADENUS

• Goal is Automation of SLA Management
• contract negotiation
• service provisioning/ activation
• monitoring
• integrated with resource management
• Service always have a SLA
• Service SLA service agreements
• SLA/ SLS management vs. Providers Business
  Processes
• TMF work
• understand impact of dynamic service creation on
  current SP business processes

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End-User Services

• IP Transport services with QoS, security features
• Value-Added services offered on top of an IP
  Network (VoiceIP, multimedia )
• The end-user in CADENUS can be
• a residential customer
• a corporate customer
• another provider (using services provided by the
  first provider)

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Levels of SLA support

• Insurance Policy Mode
• Measure performance/availability
• Give credits on SLA violation
• Provisioning Mode
• Insurance Policy but
• customers are not equal.
• Put classification/rate control/QoS devices
• Adaptation Mode
• Provisioning Mode plus
• Take action on possible SLA violation
• Allocate or take resources for customers

Quote from Verma/ Wjinen presentation (Policy 99)

• Integrated Mode
• SLA drives automated service fulfillment and
  service assurance processes

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SLA Life-Cycle

• Service Development
• Negotiation and Sales
• Implementation
• Operation and Assessment

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SLA Facets

• Network vs Application Service
• Dynamic
• Single User Instance vs Aggregated
• Call establishment vs. information transfer
• Technical
• Non Technical
• e.g. Average Call Response Time, MTPR, MTPS ...

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Business Scenarios

• Automated Service Management in the SP Domain
• design - subscription - activation - monitoring
• Example VPN data corporate voip
• Service Management in the Customer Domain
• self-service provisioning
• policies on resources purchased by SP
• monitor purchased SLA
• Inter-provider negotiation of transport services
• Service Retailer

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Service Creation - Converging Views (1)

• Allow rapid introduction of new products and
  new technologies
• 2 views for same goal
• automated service creation
• in the Operational Support System (OSS)
• Time Costs for introducing a New Service
  Offering is mainly affected by the impacts on
  OSSs
• dynamic service creation
• in the network
• to be integrated !

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Service Creation - Converging views (2)

• commonalities
• service composition approach
• SLA-aware
• infrastructure support (events, workflow/
  scripting facilities, data repositories )
• differences
• scalability goals
• performance goals
• technical approach

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OSS View Requirements for service creation

• flexible service modeling environment
• data structures
• processes
• support service composition (bundles,
  commercial offers)
• manage a variety of service activation interfaces
  
• telnet, SNMP, Policy, Dynamic Service Creation
• process logic separated -gt workflow
• both automatic and manual activities

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OSS View - Service Composition
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OSS View - OSS and Process Integration Maturity
Model
4. Integrate Horizontal Processes and Automate
Tasks
2. Maintain Service Config. Inventory
1. Maintain Resource Asset Inventory
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Network View - Dynamic Service Creation

• Phase 5 ..
• Have network boxes actively supporting service
  activation
• See michaels presentation

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Agenda

• SLA in CADENUS overview
• SLA/ Service Model
• Techniques to achieve SLA-based service creation

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Purpose of SLA/SLS modelling

• Define a flexible information model
• Support implementation of tools to automate SLA
  management processes
• Allow design of
• new services
• new commercial offers
• Allow mapping to different service architecture/
  technology
• To be shared across all CADENUS components
• Identify areas for standardization

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Layered Models

• Business Model (SLA, Service Offer)
• Related to SP Business Processes (e.g. Service
  Planning and Service Configuration)
• Includes end-customer view
• Cross-technology (e.g. both ATM PVC and VoIP)
• Service Model
• Both customer-perceived services and
  supporting services
• Independent of underlying service architecture/
  technology (DiffServ, MPLS,...)
• Resource Model
• Resources (network/ application) supporting the
  service and their configuration

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Model - Summary
Resource Model
SLA / Service Model
CIM_PolicyRule

QoSPolicyRule
CIM_MetricDefinition

Metric
1
SLA Template
instance



ServiceComponent
SAPSAP

Service Offer Quality
Service Level Objective



0..1
1
Dependency

ServiceService


Dependency
CIM_Service
CIM_SAP



1
0..1
SLA Contract
ServiceAccessBySAP
QualityDescription


QualityDescription
ServiceSAPDependency
1
1

Dependency
0..1

CIM_NetworkService

1
Client Service
Service Offer
Service
1
SAP


Service Component


1
instance

1
Service Template
0..1
CIM_QoSService
0..1
CIM_ForwardingService
0..1
Operational Service
Application Service
Connectivity Service

QoSConditioningSubService
QoSSubService
CIM_ConditioningService

Value-added Service
Infrastructural Service
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SLA Management Lifecycle - 1

• Product/Service Development
• Defines Service Templates and related SLA
  Templates
• Negotiation and Sales
• Uses Service Template and SLA Template as input
• Delivers an instantiated SLA Contract, including
  a Service Offer and the related Service Offer
  Quality

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Service Template

• Describes the Service Offering (i.e. SPs Catalog
  of Services) by means of Service Types
• After sales process is instantiated into a
  Service Offer for a specific Customer (e.g.
  describing Customer Site, POP and CPE)

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SLA Template

• Groups together a set of Parameters and Metrics
• Related to a specific Service Template
• May be used during Customer negotiation to define
  their required level of service quality
• E.g. Customer can choose between different
  Quality Levels (e.g. gold, silver, bronze) for
  the same type of Service, or can decide single
  Parameter values (e.g. Round-trip delaylt90 ms)
• SLA/Service Templates describe allowed
  combinations of options for a specific
  SLA_Contract

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SLA Contract

• Contract between Customer and Provider - Business
  nature
• SLA includes
• Description of the Service Offer
• Quality Objectives for the Service Offer
• Reports
• Remedies
• Credits
• Charges
• Escape clauses
• ...

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Service Offer

• Service instances package provided by the SP to
  the Customer
• Contains a bundle of (1..N) ServiceComponents
  visible to the Customer
• QualityDescription relates the Service Offer to
  requested Service Offer Quality
• Examples IP VPN, Corporate VoIP, VOD, Full
  Business Company

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Service Offer Quality

• Overall level of Quality agreed in the SLA
  Contract for the subscribed Service Offer
• Groups together the Service Quality Objectives
  set for each Service Component (both high-level
  and low-level services) visible within the SLA
  Contract

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Service Offer Quality - Example

• Full Business Company
• Service Bundle Quality Objectives (e.g. MTTR,
  Mean Service Availability)
• Application Hosting Service Quality Objectives
  (e.g. Application Availability, Application
  Response Time, Intrusion Detection Time)
• IP Access to ASP Service Quality Objectives (e.g.
  Packet Delay, Packet Loss, Connection
  Availability)

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SLA Management Lifecycle - 2

• Implementation
• Uses the Service Offer and the related Service
  Offer Quality for unbundling purposes
• Generates all the Service instances for both
  Client and internal services and their related
  SAPs
• Generates all the Service Level Objective
  instances for the Service instances with required
  QoS

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SLA Management Lifecycle - 3

• Implementation
• Generation of Policies / Configurations for
  network / application resources supporting
  service (CIM_Policy, classes in Resource Model)
• Operation Assessment
• metrics
• not shown in model

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Service

• Building block of SLA Model
• Containment hierarchy allows to bundle low-level
  services into high-level ones
• Client Services are the subset of Services
  included within the SLA Contract (perceived by
  the Customer)
• Dependency models constraints among Services

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Service - Examples

• Simple Services
• ATM/FR PVC
• IP Connection
• VW PDB
• Mail Service
• Composite Services
• Classic VPN
• IP VPN
• VOD
• VoIP
• Web Hosting

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Connectivity Services

• Services provided only by means of the Network
• Network Services for delivering
• data
• voice
• multimedia
• ... over multiple NW technologies
• Examples
• end-to-end connection-oriented NW Services (e.g.
  FR/ATM PVCs)
• IP services (e.g. VW PDB)
• combinations (e.g. LAN Emulation and IP Over ATM)

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Operational Services

• May be offered explicitly as extra-services
• QoP parameters (i.e. MTTR) are typically included
  within SLAs
• Are out-of-scope in this analysis
• Examples
• 7x24 Help Desk support
• Management outsourcing

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Application Services

• Value-added Services (e.g. Content and ASP) and
  Infrastructural Application Services (e.g. DNS,
  Firewall)
• Value-added Services are built on top of
  NW-bearer Services (Dependency)
• Both are integral part of the managed services
  (i.e. should be provisioned and monitored)

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Service Level Objectives

• Contains metrics in support of the SLA
• Related to a specific Service Component
• Individual Service Quality Objectives described
  in terms of
• metric and thresholds
• tolerances
• actions ?

CIM Core Policy Model ... the objectives and
metrics (Service Level Objectives, or SLOs), that
are used to specify services that the network
will provide for a given client. The SLA will
usually be written in high-level business
terminology. SLOs address more specific metrics
in support of the SLA.
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Service Level Objectives - Low-level Service
Examples

• ATM PVC SLO
• CLR Forward and Backward
• Throughput (i.e. Egress/Ingress cell within PCR)
• PVC Availability
• IP E2E Connection SLO
• Oneway (FW) Delay
• Jitter
• Packet Loss Ratio
• Web Server Hosting SLO
• Throughput (e.g. Num. of pages x Sec.)
• Web Server Availability

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SLO vs. SLS

• Similar Definitions ...
• SLO (CIM Policy Model) - ... the objectives
  and metrics (Service Level Objectives, or SLOs),
  that are used to specify services that the
  network will provide for a given client. The SLA
  will usually be written in high-level business
  terminology. SLOs address more specific metrics
  in support of the SLA.
• SLS (TEQUILA Draft) - A Service Level
  Specification (SLS) is a set of parameters and
  their values which together define the service
  offered to a traffic stream by a DS domain.
• For Diffserv SLO SLS
• CADENUS model and tools allow/ require
  specialization
• tequila SLS is a specialization of Connectivity
  Service and related SLO for IP Diffserv

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SAP

• Logical or physical element located on the
  interface between Customer and Service Provider
  domains
• SAP related to a Client Service represents the
  point at which the Service is delivered
• Used to model dependencies between Services
  spanning multiple SPs domains
• Examples
• CPE or Edge UNI
• Interdomain gateway NNI
• Ingress/Egress Interface

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Model - Comments (1)

• A core model to be extended for each new
  service and technology mapping introduced
• Extensibility through combination of metadata
  (Service Template, SLA Templates) and subclassing
  
• A Conceptual Model
• Needs mapping rules to a development model (e.g.
  XML, directory services, SQL)

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Model - Comments (2)

• Some freedom to SP using it to model its service
  catalog
• Set of Services are not predefined
• some examples will be defined (vpn, virtual
  leased line, ..)
• Tequila SLS
• Services are composed into higher-level services
  and/ or commercial offers
• Mapping Rules (not shown in model) create the
  link from Service to its implementation
• device configuration
• policies
• configuration scripts for dynamic svc creation
• workflow
• ...

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Agenda

• SLA in CADENUS overview
• SLA/ Service Model
• SLA management - Areas of work

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CADENUS Architecture
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Architecture (SM) mapping of Model
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Areas of technical work related to SLA management
in CADENUS

• Access Mediator
• negotiation of service/ SLA
• retailer interface
• standard data structure for SLA
• Service Design Environment
• see next slides
• SLA fulfillment
• see next slides
• SLA Assurance
• Semi-automated translation of SLA to plan for
  SLA monitoring
• Integration with Resource Mediator for SLA goals
  maintenance

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SLA Fulfillment

• Semi-automated translation of SLA to network
  configuration rules
• Verify correctness of network configuration with
  respect to SLA objectives
• Network-based mechanism for service activation
• Workflow/ Intelligent Agent architecture to
  coordinate plan execution
• Integration with Resource Mediator for SLA goals
  maintenance

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Service Design Environment

• Sw engineering techniques/ process to
• allow non-technical people to design new
  services/ SLA template
• ease the translation of a new service template
  into a WEB application (part of access mediator)
• allow (technical) people to define mapping rules
  to policy/ service creation/ SLA monitoring
  scripts
• Metadata for describing service/ SLA parameters
  and relationships
• Full automation feasible ?
• Some Prototyping
• JSP, Javascript for GUI
• Mapping to internal unique format for service/
  SLA via XSLT

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Relationship to other works

• TMF
• SLA Mgmt Handbook
• DMTF CIM/DEN
• Network/ BGP Model
• Tequila SLS
• IETF/ CIM Policy

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