Download PCEP Requirement for Impairment

PCEP Requirements for WSON Impairments
draft-lee-pce-wson-impairments-01.txt
Young Lee
Greg Bernstein
Jonas Martensson
Tomonori Takeda
Takehiro Tsuritani
[email protected]
Huawei
[email protected]
Grotto Networking
[email protected]
Acreo
[email protected]
NTT
[email protected]
KDDI
76th IETF – Hiroshima, Japan, November 2009
Purpose & Scope
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
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)
Small enhancements required for PCC-PCE
interface and PCE-PCE interface
Add optional
optical quality
parameters
(a) Combined R+WA+IV
(b) Separate IV from R+WA
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:
•
•
•
•
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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 reoptimization 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
doesn’t 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
76th IETF – Hiroshima, Japan, November 2009