50 likes | 348 Views
GMPLS RSVP-TE recovery extension for data plane initiated reversion draft-takacs-ccamp-revertive-ps-01. Attila Takacs attila.takacs@ericsson.com Benoit Tremblay benoit.c.tremblay@ericsson.com. IETF-72 Dublin. Background, Motivation and Objectives.
E N D
GMPLS RSVP-TE recovery extensionfor data plane initiated reversiondraft-takacs-ccamp-revertive-ps-01 Attila Takacs attila.takacs@ericsson.com Benoit Tremblay benoit.c.tremblay@ericsson.com IETF-72 Dublin
Background, Motivation and Objectives • RSVP-TE recovery extensions (RFC4872, 4873) support CP driven reversion only • Wait-to-Restore (WTR) and Hold-off (HOFF) timers must be pre-configured at the endpoints, no CP support for setting these parameters on a per LSP basis • Not a limitation for CP driven reversion/protection • Not a limitation for DP driven reversion/protection of unidirectional LSPs • However, for DP drivenreversion/protection of bidirectional LSPs these parameters need to be signaled by CP • This ID proposes the corresponding PROTECTION Object extensions
Meanwhile…MPLS-TP framework/requirementsOn recovery mechanisms… • A Framework for MPLS in Transport Networks (draft-blb-mpls-tp-framework) • MPLS-TP recovery mechanisms do not depend on a control plane and rely on MPLS-TP OAM capabilities to trigger protection switching. These mechanisms are data plane-driven and are based on MPLS-TP OAM fault management functions • This behavior can be subject to management plane or control plane control • MPLS-TP Requirements (draft-jenkins-mpls-mpls-tp-requirements) • MPLS-TP protection mechanisms MUST support revertive and non- revertive behaviour • MPLS-TP protection switching mechanisms MUST prevent frequent operation of the protection switch due to an intermittent defect • MPLS-TP protection mechanisms MUST ensureco-ordination of timing of protection switches at multiple layers to avoid races and to allow the protection switching mechanism of the server layer to fix the problem before switching at the MPLS-TP layer Requirements for explicit control of the revertive property, WTR and HOFF timers This ID is extending RSVP-TE to control these recovery aspects
PROTECTION Object extension • Alternative 1:new revertive protection bit • Control revertive property; WTR and HOFF are pre-configured 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|P|N|O|V| Reserved| LSP Flags | Reserved | Link Flags| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|R| Reserved | Seg.Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ • Alternative 2: new WTR field • Control revertive property by setting WTR timer; HOFF is pre-configured 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|P|N|O|Res| WTR | LSP Flags | Reserved | Link Flags| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|R| Reserved | Seg.Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ • Alternative 3: new WTR and HOFF fields • Most flexible: set WTR and HOFF timers on a per LSP basis 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|P|N|O| Reserved | LSP Flags | Reserved | Link Flags| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|R| Reserved | Seg.Flags | Resv. | WTR | HOFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Next steps • Discussion on alternatives • Add text on applicability