Multi-service Architecture: Evolution of Network Architecture Keith Knightson Khalid Ahmad Carrier Data Networks Nortel Networks, Canada IP-Networking/Mediacom Workshop, 24 -27 April 2001

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Multi-service ArchitectureEvolution of Network
ArchitectureKeith KnightsonKhalid
AhmadCarrier Data NetworksNortel Networks,
CanadaIP-Networking/Mediacom Workshop, 24 -27
April 2001
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Outline

• Network Evolution Trends
• General Architectural Challenges
• Example of Todays Typical Protocol Architecture
• Domains of Disruption
• Architectural Diversity
• Virtual Services Network / Virtual Transport
  Network
• Multi-service Network
• Multi-service Core Protocol Architecture
• Interworking Considerations
• Span of Control / Management
• Conclusions

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Network Evolution Trends

• Optical Infrastructure
• Capacity imperative
• Packet Based Transport Switching
• Multi-service flexibility
• Location of Intelligence (Core vs Edge)
• QoS and Bandwidth Granularity/Control
• Convergence of Control Management Aspects
• E.g., Dynamic routing vs protection switching
• Interworking with Legacy Systems

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General Architectural Challenges (1)

• Multiple Architectures currently exist
• e.g. ISDN, B-ISDN, SS7/AIN, IP, FR, etc
• Future of Multiple architectures
• Are they inevitable due to continual evolution?
• Yes, implies interworking will continue to be key
  issue
• Move to new single hierarchical architecture
• Drivers
• Functional Simplification, Bandwidth Efficiency
• Performance, Cost, etc.
• Is this realistic in long term?
• The ultimate architecture is All optical,
  plus.?
• Migration issues will be key

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General Architectural Challenges (2)

• Position of Intelligence
• Edge versus Core Intelligence
• Edge Service diversity, QoS Differentiation
• Core Survivability, Bandwidth Management,
  OAM/NM
• End-to-End Coherence issues
• All network aspects, multi-domain applicability
• Architectural Agility
• Customer adaptability
• Mix and match technologies
• Agile layering (x over y, or y over x)
• Seamless Service transparency

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Example of Todays TypicalProtocol Architecture

• Key Features
• Multiple functionally rich layers
• QoS Diversity
• Rich degree of control/management granularity

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Domain of DisruptionTransport Switching Layers
Layer 2

• Issues
• Preservation of functionality (service, control
  management)
• QoS granularity

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Protocol Architecture Diversity

• Issues
• Interworking between Differently Layered
  Architectures
• Functional Convergence
• Common Optical Infrastructure Packet-based
  Transport

Question How to deal with Architectural
Diversity?
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Virtual Services NetworkVirtual Transport Network

• Concepts
• Virtual Services Network
• Customer Service Delivery Platforms
• Virtual Transport Network
• Core Transport Switching Platforms

Y.1311 uses these concepts to describe IP VPN
Service Provision
Answer Decouple Customer Services from Transport
Facilities
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VSN/VTN Concepts

• Decoupling of services from Access Transport
  technologies allows
• Mix and match of various services with any access
  and core technology
• Exploitation of different types of technology
• Agility of service provision and customization
• Flexibility points for interdiction of
  interworking functions

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Multi-Service NetworkVSN/VTN Perspectives

• VSN/VTN multi-service approach encompasses
  Network Evolution Trends

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Multi-Service Core ProtocolArchitecture
Recursive Architectural Possibility

• What is preferred packet transport/framing
  approach? E.g
• G.707 Approach
• Generic Framing Protocol
• MPLS over Optical (GMPLS)

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Span of Control/Management
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Interworking Considerations

• Customer investment/preference means multiple
  architectures
• Multiple architectures mean interworking
• Service mapping at equivalent service layers
• Issues arising
• End-to-end coherence (service features,
  addressing, QoS, security)
• Coherent Span of Control (signaling, routing,
  etc)
• Coherent Span of Management

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Control Aspects

• Require End-to-End Coherence Functions for
• Addressing
• Session Control
• Route Control
• Feature Selection/Exploitation
• QoS
• Granularity levels, E2E consistency
• QoS interoperability
• Consistency with SLAs and availability
• Security
• Interoperability between signaling gateways

Urgent Need for coordination rationalization of
standards efforts in control domain
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Management Aspects (1)

• Require End-to-End Coherence Functions for
• Configuration Management
• Provisioning Topology Changes
• Performance Management
• Active monitoring
• Correlation to SLA QoS requests
• End-to-End consistency
• Fault Management
• End-to-End testing across multiple domains
• Fault localization across multiple domains
• Recovery/restoration across multiple domains

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Management Aspects (2)

• Security
• Access control
• Authentication
• Data Privacy
• Accounting
• Single itemized bill
• QoS/SLA correlation
• Performance/Fault correlation

Boundary between control and management becoming
blurred due to change in granularities and
response times.
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Domain of DisruptionManagement Control
Many Layers
Few Layers
Coarse Control Management Domain
Fine Control Control Signaling Domain
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Conclusions (1)

• Competing architectures will co-exist and must
  evolve
• Interworking will continue to be a key issue
• Unified Multi-Service architectures in VSN/VTN
  Framework will
• Reduce complexity
• Increase flexibility of service provision
• Simplify interworking
• Overarching coherence functions required for
  integrating control and management
• Standards co-ordination rationalization critical

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Conclusions (2)

• Two major Domains of Disruption
• Layering Implosion
• Move from many layers to fewer layers
• Fewer levels of granularity
• Greater granularity at the lower levels
• Control and Management
• Control and Management converging
• As granularities converge
• Automation reduces response times
• End-to-End overarching coherence functions
  required

Tectonic Shifts in World of Next Generation
Architecture