Network Planning, Control and Management Perspectives …conference.vde.com/ecoc-2009/programs/documents/... · 1 ©Nokia Siemens Networks I insert classification level Network Planning,

1 © Nokia Siemens Networks

I insert classification level

Network Planning, Control and Management Perspectives on Dynamic Networking

Dr. Thomas Michaelis – Nokia Siemens NetworksResearch, Technology and Platforms > Multilayer Networks and Resilience

Michael Duelli – Julius-Maximilians University of WuerzburgChair of Distributed Systems

Mohit Chamania – Technical University Carolo-Wilhelmina of Braunschweig Institute of Computer and Network Engineering

Bernhard Lichtinger – Leibniz Supercomputing Centreof the Bavarian Academy of Sciences and Humanities

Franz Rambach – Nokia Siemens NetworksResearch, Technology and Platforms > Multilayer Networks and Resilience

Stefan Türk – Dresden University of TechnologyChair for Telecommunications

Public


Outline

• Motivation

• Planning perspective

• Multi-domain network operation

• Control perspective

• Management perspective

• Conclusions

Public


Outline

• Motivation





• Conclusions

Public


Motivation

Technological progress and market competition

• Fuel decline of bandwidth cost and price (ARPU)

• Drive growth of IP services and traffic

⇒ Investment need!

Dynamic networking is one viable approach to keep cost in balance with revenues

• Improve revenue collection– Re-use network infrastructure for more users

– Differentiate by on-demand and/or QoS-guaranteed services

– also in inter-provider contexts

• Reduce cost– Automation of recurring operational

transactions

– also in inter-provider contexts

Prerequisite for proper dynamic networking

⇒Alignment of planning, control and management perspectives

Planning

Control

Management

Content: Thomas Michaelis (Nokia Siemens Networks), Michael Duelli (University of Würzburg)

Time

Re

ve

nu

e /

bit

Tra

ffic

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Outline

• Motivation


> Network design

> Network migration




• Conclusions

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Planning perspective> Network design

Inflexibility of network design due to its immanent physical nature

• Principle: “More is better … but also more expensive!”

• Trade-off between over-provisioning and hot-plugging resources

Multi-layer network design

• Architectural guidelines– Multi layer resilience (which failures covered by

which layer, escalation strategies)

• Service constraints/requirements– Traffic matrices

– Service availability, e.g. 99.9…9%

– Service quality (QoS), e.g. max. end-to-end delay

• Topological constraints– Physical layer sites & topology

• Technology constraints– Multi-layer technology & interconnection model

– Failure (FIT) rates

• Objective: minimal TCO– Multi-layer cost model

⇒ Provides necessary degrees of freedom for network operation

⇒ Network design and operation are NOT independent!

Planning

Content: Michael Duelli (University of Würzburg)

Basic Node

Slot

Slot card

AB C

DDemand

“layer”

Physical

layerA

B C

D

Logical

layer n

Logical

layer 1

…

AB C

D

AB C

D

Find path in

lower layer

Find path in

lower layer

Find path in

lower layer

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Initial/current network

Future/optimized network

Network MigrationNetwork Migration

CAPEX- Hardware

OPEX- Energy

- Penalty

- Security

IMPEX- Implementation

Integration

+ minimal costs due

to planning and

optimization

- calculation necessary

- algorithm evaluation

necessary

Integration

+ minimal costs due

to planning and

optimization

- calculation necessary

- algorithm evaluation

necessary

Overlay

+ simple

+ no service

interruption

- high CAPEX

and OPEX

Overlay

+ simple

+ no service

interruption

- high CAPEX

and OPEX

S1

S2

S3

S4

S5

optimal cost

Incremental

All Period

100G Eth

DWDM

MPLS-TP

…

Planning perspective > Network migration

Planning

Content: Stefan Türk (Technical University of Dresden)

Network design

(N+1)

Network design

(N+1)

Network design

(N)

Network design

(N)

Late investment

(or wrong

migration

sequence) may

violate SLAs

Late investment

(or wrong

migration

sequence) may

violate SLAs

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Outline

• Motivation





• Conclusions

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Multi-domain network operation

Encapsulation & hiding of information

• Grouping of network elements, control functions or switching functions

• Privacy, scalability or compatibility reasons

• Domain = provider, vendor, control, technology

• Overcoming the limited knowledge in individual domains

– Centralized databases/algorithms

– Cooperation

Centralized vs. distributed multi-domain network operation

• NMS-based /centralized

– Manual configuration and management of network and provisioned services should always be possible

– NMS tend to be single vendor and proprietary

▪ Missing inter-provider interfaces

• Control plane (CP) based / distributed

– Most beneficial in mesh topologies with more than two paths between two nodes

▪ Metro core and core

– Particular strengths in multi-layer/-domain scenarios

▪ Fast response to failures in local domain

▪ Second line of defense against multiple failures (in connection with protection mechanisms on e.g. lower layer)

▪ Less resource consumption for survivability purposes

– Scalability enhancement of control plane on IP/MPLS layer

⇒⇒⇒⇒ GMPLS as de-facto set of standards, complemented by PCE concept

Provider

Vendor

Control

Vendor

Control

Provider

Vendor

Control Control

Technology

(e.g. IP)

Technology

(e.g. DWDM)

Content: Thomas Michaelis (Nokia Siemens Networks)

Operation

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Outline

• Motivation




> GMPLS & PCE technologies

> Intra-provider path computation

> Inter-provider path computation


• Conclusions

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ControlControl perspective> GMPLS & PCE technologies

Main applications

• Traffic Engineering (TE)

– Global rerouting of traffic (minimize utilization/blocking)

• Service provisioning

– Enables client network elements to trigger tunnel setup, based on standardized user-network (UNIs) and network-network interfaces (NNIs)

• Service restoration

– Fast & flexible response to failures

– High level of survivability at relatively low cost

⇒Enabling technologies for dynamic networking in multi-layer/-domain contexts

Issues in optical networks

• Optical constraints

– Subsecond switching times more likely to be achieved in a multi-layer context (avoidance of power transients)

• Digital constraints

– Path length limited by dispersion compensation capability of DSP receivers (= implementation complexity/cost)

⇒ Network design and control NOT independent!

Static Highly dynamic

Years Sub-second

Network

Planning/

Migration

Network

Operation

Traffic

Engineering

Service

Provisioning

Service

Restoration

Service

Protection

Application domain of GMPLS & PCE technologies

Agility

Timescale

of operation

Phase of

network lifetime

Content: Thomas Michaelis (Nokia Siemens Networks)

Public


ControlControl perspective> Intra-provider path computation

Path Computation Element (PCE)

• May be seen to belong to the MP and/or CP

• Decouples (standardized) path computation request from (possibly proprietary) path computation

• Centralized execution of more complex or specialized algorithms, taking into account

– Multiple endpoints (=point-to-multipoint "paths")

– Demand/request-specific constraints (e.g. end-to-end availability or QoS requirements)

– Multiple demands at a time (=traffic engineering/TE)

– Domain-specific constraints (e.g. linear and nonlinear transmission effects on the DWDM layer)

– Multiple domains (cooperative path computation)

TEDTED

CSPF Routing

Engine

CSPF Routing

Engine

RSVP-TERSVP-TE

OSPF-TEOSPF-TE

TEDTED

OSPF-TEOSPF-TE

PCEPPCEP

PCEPPCEP

PCE Routing

Engine

PCE Routing

Engine

RSVP-TERSVP-TE

GMPLS-enabled

LER

Path

Computation

Element (PCE)

TE

Info

TE

Info

TE

Info

TE

Info

Signal-

ing

Signal-

ing

Signal-

ing

Signal-

ing

GMPLS-enabled

LER / Path

Computation

Client (PCC)

Content: Thomas Michaelis, Franz Rambach (Nokia Siemens Networks)

Control Plane

today

Control Plane

in future

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Control perspective> Inter-provider path computation

Content: Mohit Chamania (Technical University of Braunschweig)

Adaptive advance reservation of capacity for transit traffic/tunnels

• Solution to: Privacy of intra-domain topology; service blocking; frequent TED updates

Control

Root

PCE

Provider Area

Domain

PCE

Hierarchical PCE Arcitecture

Domain

PCE

Domain

TED

Domain

VNTM Co

ntr

ol P

lan

eRoot

PCE

Root

TED

Transit

TOM

TOM: Responsible for optimizing transit topologies across multiple domains under a

single root PCE

VNTM: Responsible for creating and

maintaining pre-reserved Layer-2 tunnels for

inter-domain transit topology to facilitate advance reservation

Intra Domain Topology

Transit Topology

DomainLevel

Provider AreaLevel

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Control perspective> Inter-provider path computation (2)

Inter-domain blocking w/o optical bypass Inter-domain blocking w/ optical bypass

Control

Content: Mohit Chamania (Technical University of Braunschweig)

1.0E-2

2.5E-2

2.0E-2

1.5E-2

0.5E-2

0

Inter-domain blocking

Inter-domain load [Erl]5,0E-04

8,0E-04

1,5E-03

5,9E-037,5E-03

0,0001

0,001

0,01

0,1

25 30 35 40 45 50 55

Packet layer

transit tunnels only

(starting point)

Packet layer

transit tunnels only

(starting point)

Inter-domain blocking

Lightpath establishment threshold [Gb/s]

Blocking reduces

with smaller light-

path establishment

threshold

Blocking reduces

with smaller light-

path establishment

threshold

Blocking reduces

with larger mean

available capacity

Blocking reduces

with larger mean

available capacity

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Outline

• Motivation





> Inter-provider organisation models

> Inter-provider service management

• Conclusions

Public


• Issue: Bilateral service (level) agreements ↔↔↔↔ multilateral service realization

• Always one provider as single point of contact to customer

Management perspective> Inter-provider organisation models

hierarchical cascaded

Communication between

providers

direct between customer‘s

provider and other providers

only with neighbor providers in

the chain

SLA relationship star chain

Flexibility in SLAs high low

Scaling with # of services bad good

Management

Content: Bernhard Lichtinger (Leibniz Supercomputing Center Garching)

SLA

SLASLA SLA SLA SLA

Provider AProvider A Provider BProvider B Provider CProvider C Provider AProvider A Provider BProvider B Provider CProvider C

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Management perspective> Inter-provider service management

• Element and network management complemented by inter-provider service management

Management

Content: Bernhard Lichtinger (Leibniz Supercomputing Center Garching)

Public


Outline

• Motivation





• Conclusions

Public


Conclusions

• Highlighted the prerequisites for dynamic networking:

– Planning provides the degrees of freedom required for agile network operation on a per-provider basis

– Control based on GMPLS and PCE concepts conveniently automates recurringoperational tasks especially in multi-domain/layer contexts

– E2E management ensures delivery of the committed service levels in multi-domain contexts, based on organization models, clear responsibilities and OAM functions

⇒ All of these aspects need to be aligned in order to make dynamic networking a reality

Network

Design

Traffic

Engineering

Network

Migration

Planning Control

Service

Provisioning

Service

Restoration

E2E Service

Mgmt.

Management

Documents

Network Planning, Control and Management Perspectives …conference.vde.com/ecoc-2009/programs/documents/... · 1 ©Nokia Siemens Networks I insert classification level Network Planning,