Workshop - New Paradigms for Routing in Optical Networks

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padtec.com

Workshop - New Paradigms for

Routing in Optical Networks

Efficient routing for high capacity, flexible optical

networks with different classes of service

Douglas Aguiar

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Summary

1. Photonic Networks

2. Classes of Service in Optical Networks

3. Routing for Optical Restoration

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Summary

1. Photonic Networks

2. Classes of Service in Optical Networks

3. Routing for Optical Restoration

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Photonic Networks

Photonic network

Optical network able to route lightpaths

Lightpath

Optical path inside a photonic nework

Even in today’s quasi-static networks ROADMs provide the efficient

use of the network capacity

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Topology virtualization

With proper planning complex topologies with virtual point to point

links can be established

Physical layer

DWDM layer

• Traffic growth uncertainty can be more effectively addressed

(Traffic Engineering)

• Imposes greater complexity during network planning.

• Allow the planning of complex protection architectures

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ROADM site building block

Wavelength Selective Switches (WSS) are key elements for current

ROADM architectures.

• Flexgrid capability (ITU-T G.694.1)

• Switching time

• Port to port isolation

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ROADM architecture

Mux WSS WSS Sp lit ter Demux Sp lit ter Mux Demux WSS Splitter Mux D em u x Line Interface Add/drop interface Interconnection Structure Direction Transponders Transponders Client Equipment*

*IP Router, SDH ADM

Long reach Interface Short reach Interface Optical Amplification CDC Demux CDC Mux Optical Full Mesh

Broadcast and Select

Architecture

_{Multifiber Patch}

Cord Single Fiber Patch Cord

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Summary

1. Photonic Networks

2. Classes of Service in Optical Networks

3. Routing for Optical Restoration

4. The Future and its Challenges

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Typical classes of service

• Unprotected service (1+0)

• Restorable service (1+R)

• Protected service (1+1)

• Protected and restorable service (1+1+R)

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Unprotected service (1+0)

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2 1. Two unprotected services with possible protection provided

by client layer;

2. Possible to allocate a 1+0 service disjoint to an already

provisioned service.

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Restorable service (1+R)

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RSVP-TE Signaling For GMPLS Restoration LSP draft-gandhi-ccamp-gmpls-restoration-lsp-03

1. Restoration LSP is signaled after the failure of the working LSP

is detected.

2. Restoration LSP may share resources with the failed working

LSP.

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Protected service (1+1)

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2 1. Two disjoint LSPs are established

2. Traffic is transmitted through both paths

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Protected and restorable service (1+1+R)

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RSVP-TE Signaling For GMPLS Restoration LSP draft-gandhi-ccamp-gmpls-restoration-lsp-03

1. Restoration LSP is signaled after the failure of the working LSP and/or

protecting LSP;

2. Restoration LSP may share resources with the failed working/protecting LSP;

3. Restoration LSP provides protection against a second order failure for 1+1+R.

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Summary

1. Photonic Networks

2. Classes of Service in Optical Networks

3. Routing for Optical Restoration

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Planning for the DWDM layer

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3 Physical Layer

1+R 100G Services

BSA (16) FTL (10) SPO (06) RJO (05) PAE (01) BHZ (07) CCR (14) BSA (16) FTL (10) 10 SPO (06) 10 10 RJO (05) 10 10 10 PAE (01) 4 BHZ (07) 4 4 CCR (14) 4 4 MNS (20) 4 4 4

1+1+R 100G Services

BSA (16) FTL (10) SPO (06) RJO (05) PAE (01) BHZ (07) CCR (14) BSA (16) FTL (10) 1 SPO (06) 1 5 RJO (05) 5 5 5 PAE (01) 1 BHZ (07) 5 1 CCR (14) 1 1 MNS (20) 5 1 1

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Planning for the DWDM layer

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Efficient Network Planning

In order to maximize restoration availability and minimize

cost, one can make use of:

• Efficient Routing and Wavelength Assignment algorithms

• Regeneration pools

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Summary

1. Photonic Networks

2. Classes of Service in Optical Networks

3. Routing for Optical Restoration

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Technologies

• Flexible transponders

• Software Defined

Networks

• Spatial Division

Multiplexing

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Physical dimensions

Peter J. Winzer , Making spatial multiplexing a reality Nature Photonics 8, 345–348 (2014)

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Flexible transponders

Advanced and flexible

modulation formats allow to

balance between

• Reach

• Performance

• Spectral occupation

Modulation Format Spectral efficiency [bit/s/Hz] Bits per symbol OOK 0,5 1 BPSK 0,5 1 QPSK 1 2 16-QAM 2 4 DP-QPSK 2 4 DP-16QAM 4 8 2 x 1 bit/symbol DP-BPSK 1 bit/symbol OOK 2 x 2 bit/symbol DP-QPSK 2 x 3 bit/symbol

DP-8QAM 2 x 4 bit/symbol DP-16QAM

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Centralized control benefits

• Simpler HW

• Open to third party development

But transport networks has always

been centralized (!)

Differences are:

• Standards (??)

• Open to third party

EMS/NMS

Dados Dados Dados

Dados CP Dados CP Dados CP

Software Defined Networks

SDN

Dados Dados Dados

Distributed control in packet networks Centralized control via EMS/NMS in

transport networks

Centralized control via SDN in transport networks

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Spatial Division Multiplexing

• Bandwidth growth need is a fact

• To achieve Tbps channels SDM might be useful.

D. J. Richardson, J. M. Fini & L. E. Nelson, Space-division multiplexing in optical fibres, Nature Photonics 7, 354– 362 (2013)

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ROADM interfaces

• Colorless (C)

Any port in any

unrepeatered wavelength

• Directionless (D)

Any port to any direction

• Contentionless (C)

Any port in any

wavelength

*Interconnection Structure

IS*

Line interfaces

Add/drop interfaces

Dir

ec

tion

A

Direction C

Dir

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tion

E

A/D 1 A/D 2 A/D n

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ROADM Add/Drop interfaces

CDC Demux

CDC Mux

Colorless, Directionless and Contentionless interfaces

Sw Sp Sp Sp Sp Sp Sw Sw Sw Sw Sw Sw Sw Splitter Coupler Splitter WSS

8x5 Multic

as

t

Swi

cth

Co

lo

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s

and D

ir

ec

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nless

in

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ace

Sw Sp Sp Sp Sp Sp Sw Sw Sw Sw Sw Sw Sw Tr an sp o n d er Tr an sp o n d er

CD interface for 8 channels

in a 5 degree ROADM Node

CDC interface for 8 channels

in a 5 degree ROADM Node

To/F ro m di rect io n B To/F ro m di rect io n A Fr o m di rect io n B Fr o m di rect io n A To di rect io n B To di rect io n A