Performance-Based Path Selection for Explicitly Routed Label Switched Paths (LSPs) Using TE Metric Extensions
RFC 7823
Internet Engineering Task Force (IETF) A. Atlas
Request for Comments: 7823 J. Drake
Category: Informational Juniper Networks
ISSN: 2070-1721 S. Giacalone
Microsoft
S. Previdi
Cisco Systems
May 2016
Performance-Based Path Selection for
Explicitly Routed Label Switched Paths (LSPs) Using TE Metric Extensions
Abstract
In certain networks, it is critical to consider network performance
criteria when selecting the path for an explicitly routed RSVP-TE
Label Switched Path (LSP). Such performance criteria can include
latency, jitter, and loss or other indications such as the
conformance to link performance objectives and non-RSVP TE traffic
load. This specification describes how a path computation function
may use network performance data, such as is advertised via the OSPF
and IS-IS TE metric extensions (defined outside the scope of this
document) to perform such path selections.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7823.
Atlas, et al. Informational [Page 1]
RFC 7823 Path Selection with TE Metric Extensions May 2016
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Basic Requirements . . . . . . . . . . . . . . . . . . . 4
1.2. Oscillation and Stability Considerations . . . . . . . . 4
2. Using Performance Data Constraints . . . . . . . . . . . . . 5
2.1. End-to-End Constraints . . . . . . . . . . . . . . . . . 5
2.2. Link Constraints . . . . . . . . . . . . . . . . . . . . 6
2.3. Links out of Compliance with Link Performance Objectives 6
2.3.1. Use of Anomalous Links for New Paths . . . . . . . . 7
2.3.2. Links Entering the Anomalous State . . . . . . . . . 7
2.3.3. Links Leaving the Anomalous State . . . . . . . . . . 8
3. Security Considerations . . . . . . . . . . . . . . . . . . . 8
4. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Normative References . . . . . . . . . . . . . . . . . . 8
4.2. Informative References . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 9
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
In certain networks, such as financial information networks, network
performance information is becoming as critical to data-path
selection as other existing metrics. Network performance information
can be obtained via either the TE Metric Extensions in OSPF [RFC7471]
or IS-IS [RFC7810] or via a management system. As with other TE
information flooded via OSPF or IS-IS, the TE metric extensions have
a flooding scope limited to the local area or level. This document
describes how a path computation function, whether in an ingress LSR
or a PCE [RFC4655], can use that information for path selection for
explicitly routed LSPs. The selected path may be signaled via RSVP-
TE [RFC3209] [RFC3473] or simply used by the ingress with segment
Atlas, et al. Informational [Page 2]
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