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Evaluation of Possible IGP Extensions for WSON. CCAMP WG, IETF 70th Vancouver, Canada draft-li-ccamp-wson-igp-eval-00.txt Dan Li ( danli@huawei.com ) Jianhua Gao ( gjhhit@huawei.com ) Young Lee ( ylee@huawei.com ). Objectives. Examine required information for wavelength path computation
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Evaluation of Possible IGP Extensions for WSON CCAMP WG, IETF 70th Vancouver, Canada draft-li-ccamp-wson-igp-eval-00.txt Dan Li (danli@huawei.com) Jianhua Gao (gjhhit@huawei.com) Young Lee (ylee@huawei.com)
Objectives • Examine required information for wavelength path computation • See how much is “static” • Hardware configuration • See how much is “dynamic” • Changes with network use • Examine what would happen if an IGP was used for information distribution • Help WG decide whether it is good or bad to use an IGP
What Information? • draft-bernstein-ccamp-wavelength-switched-02.txt • Section 5.2 describes the subsystem properties which are needed for path computation Static Semi-static Semi-static Dynamic • Wavelength existence • Wavelength conversion/connection • Add/Drop availability • Per-fiber wavelength availability information
Why Consider Using IGP? The IGP that is already used to advertise TE information within the WSON is a candidate solution to distribute the wavelength constraint information But there are concerns and requirements to protect the IGP…
Requirements for Use of IGP • Additional information advertised must be small • Must not affect the performance of IGP • Must scale to support different wavelength multiplexer systems • Large number of lambdas • Should be functional for other label types • There are similar possible uses in TDM devices • Should support all kinds of wavelength conversion capabilities • Input interface and lambda to output interface and lambda
Example Node for Study Glass-through Direction 3 Direction 1 Wavelength Switch 160λ 160λ Direction 2 Direction 4 160λ 160λ WavelengthConverter(limited capacity) Add/Drop
Assessment Example Consider a WDM node with 4 directions and 160λ per fiber • Wavelength configuration information per fiber: (4-byte lambda label as defined by lambda label draft) 160 * 4 = 640 bytes (static information) • Potential Wavelength Connectivity Information (one bit for each λ’s connectivity to each λ on each other fiber) 3 X 160 X 160 / 8 = 38400 bytes (semi-static) • Add/Drop Availability (one bit for eachλ) 160 / 8 = 20 bytes (semi-static) • Wavelength availability status information per fiber: (one bit represents the status of each λ) 160 / 8 = 20 bytes (dynamic)
Observations • Size of dynamic data is not an issue • Size of static data is not significant • Size of semi-static data is a concern • Several ways to compress/reduce data • Maybe it is so stable that it should be treated as static
Next Steps • Work with other drafts for consistency • “wson-frame”, “wson-info”, “lambda-label” • More research on scaling issues • Document methods for data reduction • Examine ways to reduce flooding • Comments are always appreciated