GMPLS RSVP-TE extension in support of bidirectional LSPs with asymmetric bandwidth requirements

1. GMPLS RSVP-TE extension in support of bidirectional LSPs with asymmetric bandwidth requirements draft-takacs-asym-bw-lsp-00.txt attila.takacs@ericsson.com diego.caviglia@ericsson.com dwfedyk@nortel.com IETF-68 Prague

2. Bidirectional LSPs are a subset of bidirectional connectivity with the following properties Both directions take the same path Both directions have the same protection requirements There may be different bandwidth requirements in the two directions With bidirectional LSPs TE requirements (including bandwidth) is known a priori before starting any signaling Exploit the benefits of using a single RSVP-TE message exchange Bidirectional LSP request: Upstream bw, Downstream bw • Single REVP-TE session • Path: • - SENDER_TSPEC • UPSTREAM_LABEL • - UPSTREAM_TSPEC Initiator Terminator Summary of the I-d(Assumptions and proposal)

3. Options for bidirectional connectivity • Two independent LSPs • Arbitrary TE requirements • Supported today • Two associated LSPs • Arbitrary TE requirements • Extend the ASSOCIATION object and add procedures to correlate the two directions • Bidirectional LSPs • Co-routed, symmetrical TE requirements supported today • Extend the Path message with an Upstream TSpec or Flowspec object to support asymmetrical bw

4. Two signaling exchanges Co-routed LSPs (both directions take the same path) NMS calculates an ERO for both sides Use the RRO of one direction for the ERO of the other direction Setup time is two times that of a single LSP Recovery time may be quite long due to independent failures of the LSPs Management and control plane states Association and correlation of the directions may be needed Requires states for two LSPs Flexibility All TE requirements can be different in both directions, e.g,: Different protection schemes Diverse paths Different bandwidth requirements Pro: Flexibility “general solution” Single signaling exchange Co-routed LSPs Inherently solved Setup and recovery time is the shortest possible Management and control plane states Association is inherently solved Control plane states can be correlated Flexibility Inherently co-routed LSPs From TE requirements point of view only bandwidth diversity is reasonable Pro: Co-routing and management, “optimization for certain scenarios” Independent/Associated vs. Bidirectional LSPTwo vs. single signaling exchange

5. Summary and next action proposal • “do we have a strong use case for a bidirectional service requiring the fate sharing (~co-routing of the LSPs) of both directions and fully symmetrical (recovery requirements, colors, etc) apart from the bandwidth requirements?” • Ie., single signaling exchange with asymmetric bw extension • In the core despite the services (aggregated) LSP are likely symmetrical • Towards the edges LSPs can be asymmetrical like the supported services • LSPs further up in hierarchy can also be asymmetrical • Operator feedback is highly appreciated! • Extend the scope of the draft: summarize requirements and possible extensions for both cases • Two associated LSPs • Asymmetrical Bidirectional LSPs