1. Page - 1 74 th IETF – San Francisco, CA, March 2009 A Framework for the Control and Measurement of Wavelength Switched Optical Networks (WSON) with Impairments Greg Bernsteingregb@grotto-networking.com Grotto Networkinggregb@grotto-networking.com Young Lee ylee@huawei.comylee@huawei.com Huawei Dan Lidanli@huawei.comdanli@huawei.com Huawei Giovanni Martinelligiomarti@cisco.comgiomarti@cisco.com Cisco draft-bernstein-ccamp-wson-impairments-03.txt

2. Page - 2 74 th IETF – San Francisco, CA, March 2009 Contributors Ming Chen (Huawei) Gabriele Galimberti (Cisco) Rebecca Han (Huawei) Alberto Tanzi (Cisco)

3. Page - 3 74 th IETF – San Francisco, CA, March 2009 A Framework for WSONs with Impairments Merged previous two drafts: Grotto-Huawei, and Cisco into one draft What are impairments and how do they relate to routing: –Physical processes that can alter an optical signal during transmission or other processing such as switching. RFC4054 gives an overview

4. Page - 4 74 th IETF – San Francisco, CA, March 2009 Who defines optical impairments ITU-T has an extensive recommendations that include terminology, definitions, estimation, and measurement techniques. We use ITU-T definitions for optical impairments and do not define, specify, or otherwise intrude into this domain other than to ask questions and request assistance! Impairment information models and encodings will be based on ITU-T recommendations and solicit ITU-T feedback.

5. Page - 5 74 th IETF – San Francisco, CA, March 2009 Control Plane Related Applications Impairment Aware Path Computation and Control –Our focus here –Includes path establishment and teardown Control and Collection of Optical Measurements –Interesting potential application for control plane but we don’t address this here.

6. Page - 6 74 th IETF – San Francisco, CA, March 2009 Impairment Aware Path Computation and Control Optical Requirements and Constraints –Impairment Estimation Level of Detail –Impairment Information Sharing Constraints –Impairment Validation (IV) Function IA-RWA Computing and Control Plane Architectures –Combined Routing, WA, and IV –Separate Routing, WA or IV –Routing + Distributed WA and/or IV

7. Page - 7 74 th IETF – San Francisco, CA, March 2009 Impairment Estimation Level of Detail Ignored Impairments –In certain networks of limited physical extent, topology, or for other reasons impairments may be ignored. A common case is certain types of WDM rings. Approximate Impairment Estimation –Computation of quantities such as OSNR, Q-factor, rise time budget based on a set of given impairment parameters. Detailed Impairment Estimation –Detailed simulation of BER, eye diagrams, etc… based on a set of given impairment parameters. Our initial concern

8. Page - 8 74 th IETF – San Francisco, CA, March 2009 Impairment Info Sharing Constraints Constrained impairment information sharing –Some vendors within a network may not want to share impairment information concerning their equipment or may not be using standardized impairment models. –Within limits the control plane can still function in this case and we’ll show how… Unconstrained impairment information sharing –Information concerning a network elements impairments can be shared freely via the control plane (but not necessarily beyond the control plane).

9. Page - 9 74 th IETF – San Francisco, CA, March 2009 Impairment Validation Function Functional Blocks –Transmitter and signal characterization –Optical Path characterization (channel estimation) –Receiver characterization –Estimation of signal quality (BER, Q Factor) +-----------------+ +------------+ +-----------+ | +------------+ | | | | | | | | | | Optical | | Optical | | | Optical | | | Interface |------->| Path |--->| | Channel | | | (Transmit/ | | | | | Estimation | | | Receive) | | | | | | | +------------+ +-----------+ | +------------+ | | || | | Estimation | | || | | \/ | | +------------+ | | | BER / | | | | Q Factor | | | +------------+ | +-----------------+

10. Page - 10 74 th IETF – San Francisco, CA, March 2009 IA-RWA Process Alternatives Combined RWA&IV (works with info sharing constraints) Candidates IV + RWA (works with info sharing constraints) Routing + Distributed WA & IV

11. Page - 11 74 th IETF – San Francisco, CA, March 2009 Candidates IV + RWA via PCE

12. Page - 12 74 th IETF – San Francisco, CA, March 2009 Protocol Implications Routing, Signaling, PCEP, need for an information model… +-------------------+----+----+----------+--------+ | IA-RWA Option |PCE |Sig |Info Model| Routing| +-------------------+----+----+----------+--------+ | Combined |Yes | No | Yes | Yes | | IV & RWA | | | | | +-------------------+----+----+----------+--------+- | IV-Candidates |Yes | No | Yes | Yes | | + RWA | | | | | +-------------------+----+----+----------+--------+ | Routing + |No | Yes| Yes | No | |Distributed IV, RWA| | | | | +-------------------+----+----+----------+--------+

13. Page - 13 74 th IETF – San Francisco, CA, March 2009 Next Steps/Issues Informational working group document? –All frameworks are informational –Gives us something to liaison with ITU-T Continue refining requirements, architectures and models –Discuss ITU-T “black link” model from G.698.1 and G.698.2 and which of our architectures applies to this situation. Continue discussions with ITU-T