RFC 4920: Crankback Signaling Extensions for MPLS and GMPLS RSVP-TE
In plain English — editorial summary, not part of the RFC
In a distributed, constraint-based routing environment, the information used to compute a path may be out of date. This means that Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineered (TE) Label Switched Path (LSP) setup requests may be blocked by links or nodes without sufficient resources. Crankback is a scheme whereby setup failure information is returned from the point of failure to allow new setup attempts to be made avoiding the blocked resources. Crankback can also be applied to LSP recovery to indicate the location of the failed link or node. This document specifies crankback signaling extensions for use in MPLS signaling using RSVP-TE as defined in "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, and GMPLS signaling as defined in "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3473. These extensions mean that the LSP setup request can be retried on an alternate path that detours around blocked links or nodes. This offers significant improvements in the successful setup and recovery ratios for LSPs, especially in situations where a large number of setup requests are triggered at the same time. [STANDARDS-TRACK]
Document record
- Document ID
- RFC4920
- Published
- July 2007
- Authors
- A. Farrel; A. Satyanarayana; A. Iwata; N. Fujita; G. Ash
- Status
- PROPOSED STANDARD
- Stream
- IETF
- Area
- rtg
- Pages
- 38
- Also known as
- —
Topics
Related documents
Ranked automatically by shared keywords, IETF area and stream — not by editorial selection.
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- RFC 4726A Framework for Inter-Domain Multiprotocol Label Switching Traffic EngineeringCurrent
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- RFC 5439An Analysis of Scaling Issues in MPLS-TE Core NetworksCurrent
February 2009
- RFC 8413Framework for Scheduled Use of ResourcesCurrent
July 2018
- RFC 4972Routing Extensions for Discovery of Multiprotocol (MPLS) Label Switch Router (LSR) Traffic Engineering (TE) Mesh MembershipCurrent
July 2007
- RFC 4687Operations and Management (OAM) Requirements for Point-to-Multipoint MPLS NetworksCurrent
September 2006
- RFC 5330A Link-Type sub-TLV to Convey the Number of Traffic Engineering Label Switched Paths Signalled with Zero Reserved Bandwidth across a LinkCurrent
October 2008
- RFC 3988Maximum Transmission Unit Signalling Extensions for the Label Distribution ProtocolCurrent
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