IETF-70th Vancouver1 Extensions to GMPLS RSVP-TE for Bidirectional Lightpath with the Same Wavelength draft-xu-rsvpte-bidir-wave-01 Sugang Xu, Hiroaki Harai, Daniel King

IETF-70th Vancouver2 Special optical network scenarios for bidirectional lightpath provisioning –Fixed tuned wavelength transponders –Fixed wavelength multiplexers/demultiplexers like AWGs –Some types of ROADM need to add/drop wavelength simultaneously –Wavelength continuity constraint different wavelengthsSolution of port-remapping problem of bidirectional lightpath with different wavelengths using fix-tuned wavelength media converter (MC) True needs ofFastProvisioningTrue needs of Fast Provisioning capability configuration errors failure, –In cases of configuration errors, transceiver failure, etc. –Quick recovery capabilities –Quick recovery capabilities are critical to network stability. To Recap: Support for Bidirectional Lightpath with the Same Wavelength on Both Directions Would Be Advantageous MC GE Optical End Node Core Node MC GE Optical End Node Core Node Lack port-remapping flexibility With flexibility by OXC

IETF-70th Vancouver3 Do Solutions Exist? Two unidirectional lightpaths in converse directions with the same wavelength (A1) –Sequentially verify the same wavelength availability in both directions and crankback if failure. Label set and Upstream label + crankback (A2) –Specify wavelength on both directions Label set and Upstream Label set (A3) –Add constraint in wavelength available information updating process on both directions in Label set and Upstream Label set Label Set Object and Bidirectional Lightpath (Prop) LSP_ATTRIBUTES –Using LSP_ATTRIBUTES Object [RFC 4420] Label set –Upstream-and-Downstream common free wavelengths information updating at each node and carried by Label set

IETF-70th Vancouver4 Shorter Provisioning Time and Lower Blocking Probability 1 round message exchanging a b c Path Msg Resv Meg Path Msg Resv Meg Avg. Provisioning Time (W=32, Δt=0.01s) Blocking Probability (W=32) Single wavelength occupation rate/link W W: Number of wavelengths H H: Number of Hops A1 A1: Uni Setups A2 A2: With UpLabel A3 A3: With UpLabel set Prop Prop: With Label set Rt Rt: Avg. provisioning time P b P b : Blocking probability Avg. time per hop

IETF-70th Vancouver5 PCE Applicability - Link Bundling Issue PCE path computation problems However, it may actually be the case that the lambda is only available in one direction on one component link, and the other direction is only available on a different component link. –May occur when computing bidirectional lightpaths. In a GMPLS network where multiple component links are aggregated into a link bundle and advertised as a single bidirectional TE link, the Traffic Engineering Database (TED) may indicate the availability of a particular lambda in both directions on the TE link. However, it may actually be the case that the lambda is only available in one direction on one component link, and the other direction is only available on a different component link. In this scenario, creating an end-to-end path that uses the same lambdas and the same component links in both directions presents a PCE path computation problem. verify –Use signaling to verify the solution received from PCE.

IETF-70th Vancouver6 PCE Applicability - Unified Signaling Solutions With RWA done by PCE one wavelength labelSuggested label –Given a routing and wavelength assignment solution e.g. derived from a PCE, an ingress node can put one wavelength label in Label set or a Suggested label object to specify the wavelength. With only routing done by PCE egress node –An ingress node can set one or more available wavelength label objects in Label set, and let the egress node resolve the wavelength assignment in a distributed fashion. No interaction with PCE quick recovery –Because this signaling solution can resolve wavelength assignment problem itself, even without interaction with a PCE, by using an explicit route e.g. manually, it is still possible to establish a bidirectional lightpath. For example, for quick recovery from failures, bidirectional signaling may negate a PCE request.

IETF-70th Vancouver7 Next Steps Consensus is that support for same wavelength bidirectional lightpath is important for quick recovery, and fast provisioning. Is this proposal necessary right now? Feedback from the previous WG has been positive, but there is a need to clarify requirements. –Do we need requirements document? The authors will continue to work on the draft and would like to request additional feedback from WG. Especially from Operators and relevant Vendors. –Referenced in “draft-bernstein-ccamp-wson-signaling-00.txt”