Applicability of GMPLS and PCE to Wavelength Switched Optical Networks draft-bernstein-ccamp-wavelength-switched-00.txt Greg Bernstein gregb@grotto-networking.com Grotto Networking Young Lee ylee@huawei.com Huawei 69th IETF – Chicago, July 2007

Motivation This draft addresses the requirements and applicability of GMPLS and PCE to dynamic Wavelength Switched Optical Networks (WSON). Advances in Optical Technology/Practice Tunable Lasers Reconfigurable Optical Add/Drop Multiplexers (ROADMs) Maturing Physical Layer Standards Wavelength Grids (dense and coarse) WDM interface definitions and signal types 69th IETF – Chicago, July 2007

Problem/Issue Statement Can current GMPLS/PCE control WDM based systems consisting of tunable laser transmitters and reconfigurable optical add/drop multiplexers (ROADM) or Wavelength Selective Switches (WSS)? Not quite! We address the areas in which GMPLS/PCE protocols need to be enhanced in this draft. Lambda switching was an original GMPLS motivation… 69th IETF – Chicago, July 2007

Tunable laser transmitters, WDM links Network Assumptions Tunable laser transmitters, WDM links A variety of wavelength selective switching elements May not always have wavelength conversion capabilities No wavelength conversion, implies wavelength continuity constraint Partial wavelength conversion Full wavelength conversion, e.g., WDM links plus electronic switch fabric 69th IETF – Chicago, July 2007

Routing and Wavelength Assignment (RWA) Find a path and assign wavelength(s) No wavelength conversion: Need to find a path such that a single wavelength can be used from source to destination. Partial wavelength conversion: Need to find a path such that wavelength can only change at points in the network with wavelength converters. Full wavelength conversion: Only need to find path, wavelengths can be assigned locally between switching elements. 69th IETF – Chicago, July 2007

Implications for GMPLS Signaling Labels  Lambdas (Standard) Would prefer global meaning to lambda labels to reduce manual configuration and aid interoperability. See T. Otani’s draft. Wavelength Assignment (Standard) Using explicit label sub-TLV in the ERO New optical signals coming “online” (Issue) Bit rate isn’t sufficient to characterize signal, can add in modulation format as in ITU-T G.959.1 where modulation format and rate class are defined. 69th IETF – Chicago, July 2007

Implications for GMPLS Routing WDM Link Bandwidth Need to know what lambdas are available on which links Representing Wavelength Conversion Need to know the wavelength conversion capabilities of switching elements Asymmetrical Switching Elements See Wataru Imajuku’s draft 69th IETF – Chicago, July 2007

Implications for PCE RWA is a computationally intensive problem to solve Well suited to a PCE architecture rather than requiring this computation to be run on all LSC LSRs. PCE needs to know Tuning range of source transmitter laser Link lambda resources Locations and capabilities of wavelength converters Switching constraints (see Wataru’s draft) PCEP enhancements to support additional parameters RWA capable PCE via PCE Discovery 69th IETF – Chicago, July 2007

Summary & Next Steps Summary Next Steps? Wavelength Switched Optical Networks are maturing technically and commercially to support it GMPLS/PCE needs to be enhanced. Next Steps? Within Charter? Sufficient interest? Document types Requirements, Solutions, Applicability statement… 69th IETF – Chicago, July 2007