Evaluation of Possible IGP Extensions for WSON

1
Evaluation of Possible IGP Extensions for WSON

• CCAMP WG, IETF 71st Philadelphia, PA - USA
• draft-li-ccamp-wson-igp-eval-00.txt
• Dan Li (danli_at_huawei.com)
• Jianhua Gao (gjhhit_at_huawei.com)
• Young Lee (ylee_at_huawei.com)

2
Typical WDM Node
Direction 3
Direction 1
Wavelength Switch
Direction 2
Direction 4
Wavelength Converter
Add/Drop
3
Wavelength Path Computation

• draft-bernstein-ccamp-wavelength-switched-03.txt,
  section 5.2 describes the subsystem properties
  which may be conveyed via an IGP
• Factors should be considered in wavelength path
  computation

• Wavelength conversion constraints
• Wavelength connectivity
• Add/Drop availability
• Per-fiber wavelength availability information

4
Why IGP?

• The IGP that is already used to advertise TE
  information within the WSON is a candidate
  solution to distribute the wavelength constraint
  information

5
Requirements for IGP Extension

• The constraint information should be small, so
  that it must not affect the performance of IGP
• IGP extension should support all kinds of
  wavelength conversion capabilities
• IGP extension should support the scalability of
  different wavelength multiplexer systems

6
Assessment Example

• Consider 4 directions 160?WDM node
• Wavelength label information
• 160 4 640 bytes
• Wavelength available status information of each
  fiber (each bit represents the ?status)
• 160 / 8 20 bytes
• Potential Wavelength Connectivity Information for
  each fiber (each bit represents the
  ?connectivity)
• 3 X 160 X 160 / 8 38400 bytes
• Note there are several ways can reduce the size
  of potential wavelength connectivity information
  dramatically.

7
Next Steps

• Potential Wavelength Connectivity Information is
  not changed dynamically, so maybe only the
  wavelength available status information needs to
  be advertised with LSA
• Add/Drop capability information may need to be
  distributed in WSON
• Work with wson-frame, wson-info and
  lambda-label drafts to make these drafts
  consistent
• Comments are always appreciated