76th IETF – Hiroshima, Japan, November 2009 PCEP Requirements for WSON Impairments Young Huawei Greg Grotto Networking Jonas Martensson Acreo Tomonori NTT Takehiro Tsuritani KDDI draft-lee-pce-wson-impairments-01.txt

76th IETF – Hiroshima, Japan, November 2009 Purpose & Scope This memo provides application-specific requirements for the Path Computation Element communication Protocol (PCEP) for the support of Impairments in Wavelength Switched Optical Networks (WSON). From a path computation perspective, optical impairments are additional constraints on the process of determining an optical light path. Aligned with CCAMP WG draft on Optical Impairments

76th IETF – Hiroshima, Japan, November 2009 WSON PCE Architectures (adopted from WSON Impairment Framework – CCAMP WG draft) (a) Combined R+WA+IV (b) Separate IV from R+WA Small enhancements required for PCC-PCE interface and PCE-PCE interface Add optional optical quality parameters

76th IETF – Hiroshima, Japan, November 2009 A new RWA path request/reply The PCReq Message MAY include some specific measure of optical signal quality to which all feasible paths should conform: The BER limit Q factor OSNR + Margin PMD The PCRep Message MUST include the route, wavelengths assigned to the route and an indicator that says if the path conforms to the required quality or not. In the case where a valid path is not found, the PCRep Message MUST include why the path is not found (e.g., no route, wavelength not found, BER failure, etc.) (Re-optimization) If a BER limit was required in the original path request then a BER limit MUST be furnished in the re- optimization request. Otherwise, furnishing a BER limit is optional. In the case where a valid path is not found, the PCRep Message MUST include why the path is not found (e.g., no route, wavelength not found, BER failure, etc.)

76th IETF – Hiroshima, Japan, November 2009 RWA and IV Separation As explained in [WSON-IMP] separating the impairment validation process from the RWA process may be necessary to deal with impairment sharing constraints and black links. IV-Candidates PCE delivers paths between a source and destination that are optically viable, it doesnt necessarily know about resource utilization nor does it perform optimization.

76th IETF – Hiroshima, Japan, November 2009 Next Steps Adopt as a WG document Keep aligned with CCAMP impairment WG document