Evaluation of Possible IGP Extensions for WSON CCAMP WG, IETF 70th Vancouver, Canada draft-li-ccamp-wson-igp-eval-00.txt Dan Li Jianhua Gao Young Lee

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 Wavelength existence Wavelength conversion/connection Add/Drop availability Per-fiber wavelength availability information Static Semi-static Dynamic

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 Wavelength Switch Wavelength Converter (limited capacity) Add/Drop Direction 1 Direction 2 Direction 3 Direction 4 160λ Glass-through

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 = bytes (semi-static) Add/Drop Availability (one bit for each λ) 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