1. OSPF Extensions in Support of RWA in WSONs CCAMP WG, IETF 76th, Hiroshima, Japan draft-zhang-ccamp-rwa-wson-routing-ospf-02.txt Fatai Zhang (zhangfatai@huawei.com) Young Lee(ylee@huawei.com) Jianrui Han(hanjianrui@huawei.com) Greg Bernstein (gregb@grotto-networking.com) Yunbin Xu (xuyunbin@mail.ritt.com.cn)

2. OSPF Extensions in WSON Defines extensions to the OSPF routing protocol in support of RWA in WSONs Follows from draft-ietf-ccamp-rwa-info-05.txt and draft-ietf- ccamp-rwa-wson-encode-03.txt No consideration of optical impairment routing related information is included in this document

3. Changes from 01.txt Add descriptions to indicate the WSON specific information is optional Some editorial changes

4. WSON Specific Info: Node sub-TLVs Switch Connectivity Matrix Optional Wavelength Converter Pool info Optional Wavelength Converter Accessibility Wavelength Conversion Range WC Usage State No Connectivity Matrix sub-TLV Assume that the switches are symmetric switching Wavelength conversion functionality Wavelength Converter Accessibility, Wavelength Conversion Range and WC Usage State sub-TLVs should appear in the LSAs

5. WSON Specific Info: Link sub-TLVs Port Wavelength Restriction Optional Available Wavelengths Optional Shared Backup Wavelengths Optional No restrictions on wavelength Port Wavelength Restrictions sub-TLV should not appear in the LSAs In order to be able to compute RWA, Available Wavelengths sub-TLV may appear in the LSAs. Without available wavelength information, path computation need guess what lambdas may be available (high blocking probability or distributed wavelength assignment may be used). No wavelength backup functionality Shared Backup Wavelengths sub-TLV should not appear

6. Next Steps Adopt it as a WG document Refine it according to the feedback from the meeting or mailing list Keep it consistent with the latest [WSON- Encode]

7. Additional slides if needed

8. Example Node for Study Wavelength Switch Wavelength Converter (limited capacity) Add/Drop Direction 1 Direction 2 Direction 3 Direction 4 160λ Glass-through

9. Wavelength Continuity Constraint In the case of no wavelength converter, a light path must be set up subject to the "wavelength continuity" constraint. So, Wavelength availability information is very important for RWA computation process.

10. Connectivity Matrix It is necessary to identify which ingress ports and wavelengths can be connected to (the same wavelength on) a specific egress port. The switching devices in WSONs are highly asymmetric.

11. Wavelength Converter Pool Model.. Wavelength converters are considered a scarce resource. WI (I, p) = {0,1}: whether ingress port i can reach potentially reach wavelength converter p. WC (j) = {0,1}: dependent upon whether wavelength converter j in the pool is in use. WE (p, k) = {0,1}: whether the output from wavelength converter p can reach egress port k.

12. Wavelength Availability Information Considering that the continuity of the available or unavailable wavelength set can be scattered for the dynamic wavelength availability, so it may burden the routing to reorganize the wavelength set information when the Inclusive (/Exclusive) List (/Range) approaches are used to represent wavelength availability information. Therefore, it is RECOMMENDED that only the Bitmap Set be used for representation wavelength availability information. So, it is easy to use the comparatively fixed BitMap to present wavelength availability information (just change the value of the BitMap)