72th IETF – Dublin, Ireland, July 2008Page - 1

Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks

(WSON)

Greg Bernstein gregb@grotto-networking.comGrotto Networking

Young Lee ylee@huawei.comHuawei

Wataru Imajuku imajuku.wataru@lab.ntt.co.jpNTT

draft-ietf-ccamp-wavelength-switched-00.txt

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Authors/Contributors

• Snigdho Bardalai (Fujitsu) • Greg Bernstein (Grotto Networking)• Diego Caviglia (Ericsson)• Wataru Imajuku (NTT)• Daniel King (Aria Networks) • Young Lee (Huawei)• Dan Li (Huawei)• Itaru Nishioka (NEC Corp.)• Lyndon Ong (Ciena)• Jonathan Sadler (Tellabs)

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WSON Framework

• Describes wavelength switched optical networks (WSON), subsystems and associated processes. Emphasizing those aspects that are different from other technologies that utilize a GMPLS control plane.

• Optical impairments are not currently considered in any depth since different approaches to impairments are used in different types of WSONs.

• Summarize implications to GMPLS routing and signaling, and to PCE protocols.

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Contents

• WDM systems from control plane point of view (new path computation constraints)– WDM links

– Laser Transmitter/Modulator

– ROADMs, FOADMs, and OXCs

– Wavelength Converters

• Discussion of RWA problem• Discussion of Signaling, Routing and PCE

“centric” approaches• Implications for GMPLS and PCE

– Signaling, Routing, PCEP, etc…

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Relation to ITU-T Documents

• Based on ITU-T data plane models and documents– G.872 Architecture of optical transport networks (drafted new

section explaining this and cite)– G.65x optical fiber specifications (cited)– G.671 Transmission characteristics of optical components and

subsystems (this rec. includes definitions of OADM, splitter, combiner, etc… will cite in next revision)

– G.959.1, Optical Transport Network Physical Layer Interfaces, March 2006 (cited)

– G.694.1,.2 Spectral grids for WDM applications (cited)– G Supplement 39, Optical system design and engineering

considerations, February 2006. (cited)– G Supplement 43, Transport of IEEE 10G base-R in optical

transport networks (OTN), November 2006. (cited)

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Next Steps

• Add section relating this work to ITU-T G.872 architecture– Work to resolve some modeling issues when

wavelength converters are included.

• Usage Scenarios

• Alignment with emerging drafts such as info model, encoding and signaling.

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G.872 Optical Transport Network Architecture (example)

Optical Amplifier #1

Optical Amplifier #2

Optical Add/Drop

multiplexor

Optical Multiplexor

Optical De-multiplexor

= Optical Fiber

= Optical Support Channel for “Transport layer”

= Optical Support Channel for “multiplex layer”

OCh

OMS

OTS OTS OTS

OCh

OMS

OTS

OCh

OMS

OTS

Optical Channel

Optical Multiplex SectionOptical Transport Section

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Including wavelength converters

• ITU-T Models– G.872 OCh characteristic information (CI): maximum bandwidth

and SNR (Section 5.3). – Example of OCh through a wavelength converter in Appendix I,

since the wavelength converter doesn’t change the CI this doesn’t change layers.

– G.709 “… OCh transports a digital client signal between 3R regeneration points.”

• Framework draft uses “Lightpath”– We didn’t define the characteristic information for this yet but

signaling drafts are leaning towards such information as modulation, modulation parameters, bit rate and FEC.

• Most (?) wavelength converters are OEO and are also 3R regenerators.– Would like to handle connection through wavelength converters as

a single LSP without stitching RFC5150 if possible for most common cases.