draft-ietf-teas-te-express-path-02.txt   draft-ietf-teas-te-express-path-03.txt 
TEAS Working Group A. Atlas TEAS Working Group A. Atlas
Internet-Draft J. Drake Internet-Draft J. Drake
Intended status: Informational Juniper Networks Intended status: Informational Juniper Networks
Expires: December 11, 2015 S. Giacalone Expires: January 28, 2016 S. Giacalone
Unaffiliated Unaffiliated
D. Ward
S. Previdi S. Previdi
C. Filsfils
Cisco Systems Cisco Systems
June 9, 2015 July 27, 2015
Performance-based Path Selection for Explicitly Routed LSPs using TE Performance-based Path Selection for Explicitly Routed LSPs using TE
Metric Extensions Metric Extensions
draft-ietf-teas-te-express-path-02 draft-ietf-teas-te-express-path-03
Abstract Abstract
In certain networks, it is critical to consider network performance In certain networks, it is critical to consider network performance
criteria when selecting the path for an explicitly routed RSVP-TE criteria when selecting the path for an explicitly routed RSVP-TE
LSP. Such performance criteria can include latency, jitter, and loss LSP. Such performance criteria can include latency, jitter, and loss
or other indications such as the conformance to link performance or other indications such as the conformance to link performance
objectives and non-RSVP TE traffic load. This specification uses objectives and non-RSVP TE traffic load. This specification uses
network performance data, such as is advertised via the OSPF and ISIS network performance data, such as is advertised via the OSPF and ISIS
TE metric extensions (defined outside the scope of this document) to TE metric extensions (defined outside the scope of this document) to
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This Internet-Draft will expire on December 11, 2015. This Internet-Draft will expire on January 28, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Basic Requirements . . . . . . . . . . . . . . . . . . . 4 1.1. Basic Requirements . . . . . . . . . . . . . . . . . . . 3
1.2. Oscillation and Stability Considerations . . . . . . . . 4 1.2. Oscillation and Stability Considerations . . . . . . . . 4
2. Using Performance Data Constraints . . . . . . . . . . . . . 5 2. Using Performance Data Constraints . . . . . . . . . . . . . 5
2.1. End-to-End Constraints . . . . . . . . . . . . . . . . . 5 2.1. End-to-End Constraints . . . . . . . . . . . . . . . . . 5
2.2. Link Constraints . . . . . . . . . . . . . . . . . . . . 6 2.2. Link Constraints . . . . . . . . . . . . . . . . . . . . 6
2.3. Links out of compliance with Link Performance Objectives 6 2.3. Links out of compliance with Link Performance Objectives 6
2.3.1. Use of Anomalous Links for New Paths . . . . . . . . 7 2.3.1. Use of Anomalous Links for New Paths . . . . . . . . 7
2.3.2. Links entering the Anomalous State . . . . . . . . . 7 2.3.2. Links entering the Anomalous State . . . . . . . . . 7
2.3.3. Links leaving the Anomalous State . . . . . . . . . . 8 2.3.3. Links leaving the Anomalous State . . . . . . . . . . 8
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 4. Security Considerations . . . . . . . . . . . . . . . . . . . 8
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 5. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
6.1. Normative References . . . . . . . . . . . . . . . . . . 8 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.2. Informative References . . . . . . . . . . . . . . . . . 9 7.1. Normative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 7.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. Introduction
In certain networks, such as financial information networks, network In certain networks, such as financial information networks, network
performance information is becoming as critical to data path performance information is becoming as critical to data path
selection as other existing metrics. Network performance information selection as other existing metrics. Network performance information
can be obtained via either the TE Metric Extensions in OSPF [RFC7471] can be obtained via either the TE Metric Extensions in OSPF [RFC7471]
or ISIS [I-D.ietf-isis-te-metric-extensions] or via a management or ISIS [I-D.ietf-isis-te-metric-extensions] or via a management
system. As with other TE information flooded via OSPF or ISIS, the system. As with other TE information flooded via OSPF or ISIS, the
TE metric extensions have a flooding scope limited to the local area TE metric extensions have a flooding scope limited to the local area
or level. This document describes how a path computation function, or level. This document describes how a path computation function,
whether in an ingress LSR or a PCE[RFC4655] , can use that whether in an ingress LSR or a PCE[RFC4655] , can use that
information for path selection for explicitly routed LSPs. The information for path selection for explicitly routed LSPs. The
selected path may be signaled via RSVP-TE [RFC3209] or simply used by selected path may be signaled via RSVP-TE [RFC3209], [RFC3473] or
the ingress with segment routing simply used by the ingress with segment routing
[I-D.ietf-spring-segment-routing-mpls] to properly forward the [I-D.ietf-spring-segment-routing-mpls] to properly forward the
packet. Methods of optimizing path selection for multiple parameters packet. Methods of optimizing path selection for multiple parameters
are generally computationally complex. However, there are good are generally computationally complex. However, there are good
heuristics for the delay-constrained lowest-cost (DCLC) computation heuristics for the delay-constrained lowest-cost (DCLC) computation
problem [k-Paths_DCLC] that can be applied to consider both path cost problem [k-Paths_DCLC] that can be applied to consider both path cost
and a maximum delay bound. Some of the network performance and a maximum delay bound. Some of the network performance
information can also be used to prune links from a topology before information can also be used to prune links from a topology before
computing the path. computing the path.
The path selection mechanisms described in this document apply to The path selection mechanisms described in this document apply to
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objectives, then any link which has the Anomalous bit set in the Link objectives, then any link which has the Anomalous bit set in the Link
Los sub-TLV should be treated as if it fails the exclude-any resource Los sub-TLV should be treated as if it fails the exclude-any resource
attributes filter. If the answer to (a) is no for link jitter attributes filter. If the answer to (a) is no for link jitter
performance objectives, then any link that has the Anomalous bit set performance objectives, then any link that has the Anomalous bit set
in the Unidirectional Delay Variation sub- in the Unidirectional Delay Variation sub-
TLV[I-D.ietf-isis-te-metric-extensions] should be treated as if it TLV[I-D.ietf-isis-te-metric-extensions] should be treated as if it
fails the exclude-any resource attributes filter. fails the exclude-any resource attributes filter.
2.3.2. Links entering the Anomalous State 2.3.2. Links entering the Anomalous State
When the Anomalous bit transitions from clear to set, this indicates
that the associated link has entered the Anomalous state with respect
to the associated parameter; similarly, a transition from set to
clear indicates that the Anomalous state has been exited for that
link and associated parameter.
When a link enters the Anomalous state with respect to a parameter, When a link enters the Anomalous state with respect to a parameter,
this is an indication that LSPs using that link might also no longer this is an indication that LSPs using that link might also no longer
be in compliance with their performance bounds. It can also be be in compliance with their performance bounds. It can also be
considered an indication that something is changing that link and so considered an indication that something is changing that link and so
it might no longer be trustworthy to carry performance-critical it might no longer be trustworthy to carry performance-critical
traffic. Naturally, which performance criteria are important for a traffic. Naturally, which performance criteria are important for a
particular LSP is dependent upon the LSP's configuration and thus the particular LSP is dependent upon the LSP's configuration and thus the
compliance of a link with respect to a particular link performance compliance of a link with respect to a particular link performance
objective is indicated per performance criterion. objective is indicated per performance criterion.
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3. IANA Considerations 3. IANA Considerations
This document includes no request to IANA. This document includes no request to IANA.
4. Security Considerations 4. Security Considerations
This document is not currently believed to introduce new security This document is not currently believed to introduce new security
concerns. concerns.
5. Acknowledgements 5. Contributors
Dave Ward and Clarence Filsfils contributed to this document.
6. Acknowledgements
The authors would like to thank Curtis Villamizar for his extensive The authors would like to thank Curtis Villamizar for his extensive
detailed comments and suggested text in the Section 1 and detailed comments and suggested text in the Section 1 and
Section 1.2. The authors would like to thank Dhruv Dhody for his Section 1.2. The authors would like to thank Dhruv Dhody for his
useful comments, and his care and persistence in making sure that useful comments, and his care and persistence in making sure that
these important corrections weren't missed. The authors would also these important corrections weren't missed. The authors would also
like to thank Xiaohu Xu and Sriganesh Kini for their review. like to thank Xiaohu Xu and Sriganesh Kini for their review.
6. References 7. References
6.1. Normative References 7.1. Normative References
[I-D.ietf-isis-te-metric-extensions] [I-D.ietf-isis-te-metric-extensions]
Previdi, S., Giacalone, S., Ward, D., Drake, J., Atlas, Previdi, S., Giacalone, S., Ward, D., Drake, J., Atlas,
A., Filsfils, C., and W. Wu, "IS-IS Traffic Engineering A., Filsfils, C., and W. Wu, "IS-IS Traffic Engineering
(TE) Metric Extensions", draft-ietf-isis-te-metric- (TE) Metric Extensions", draft-ietf-isis-te-metric-
extensions-06 (work in progress), April 2015. extensions-07 (work in progress), June 2015.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001. Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<http://www.rfc-editor.org/info/rfc3209>.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
Previdi, "OSPF Traffic Engineering (TE) Metric Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, March 2015. Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<http://www.rfc-editor.org/info/rfc7471>.
6.2. Informative References 7.2. Informative References
[hop-count_DCLC] [hop-count_DCLC]
Agrawal, H., Grah, M., and M. Gregory, "Optimization of Agrawal, H., Grah, M., and M. Gregory, "Optimization of
QoS Routing", 6th IEEE/AACIS International Conference on QoS Routing", 6th IEEE/AACIS International Conference on
Computer and Information Science 2007, 2007, Computer and Information Science 2007, 2007,
<http://ieeexplore.ieee.org/xpl/ <http://ieeexplore.ieee.org/xpl/
articleDetails.jsp?arnumber=4276447>. articleDetails.jsp?arnumber=4276447>.
[I-D.ietf-spring-segment-routing-mpls] [I-D.ietf-spring-segment-routing-mpls]
Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., Filsfils, C., Previdi, S., Bashandy, A., Decraene, B.,
skipping to change at page 9, line 31 skipping to change at page 9, line 41
[k-Paths_DCLC] [k-Paths_DCLC]
Jia, Z. and P. Varaiya, "Heuristic methods for delay Jia, Z. and P. Varaiya, "Heuristic methods for delay
constrained least cost routing using k-shortest-paths", constrained least cost routing using k-shortest-paths",
IEEE Transactions on Automatic Control 51(4), 2006, IEEE Transactions on Automatic Control 51(4), 2006,
<http://paleale.eecs.berkeley.edu/~varaiya/papers_ps.dir/ <http://paleale.eecs.berkeley.edu/~varaiya/papers_ps.dir/
kdclc-ieeev4.pdf>. kdclc-ieeev4.pdf>.
[RFC3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec, [RFC3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec,
J., Courtney, W., Davari, S., Firoiu, V., and D. J., Courtney, W., Davari, S., Firoiu, V., and D.
Stiliadis, "An Expedited Forwarding PHB (Per-Hop Stiliadis, "An Expedited Forwarding PHB (Per-Hop
Behavior)", RFC 3246, March 2002. Behavior)", RFC 3246, DOI 10.17487/RFC3246, March 2002,
<http://www.rfc-editor.org/info/rfc3246>.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473, DOI
10.17487/RFC3473, January 2003,
<http://www.rfc-editor.org/info/rfc3473>.
[RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration [RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration
Guidelines for DiffServ Service Classes", RFC 4594, August Guidelines for DiffServ Service Classes", RFC 4594, DOI
2006. 10.17487/RFC4594, August 2006,
<http://www.rfc-editor.org/info/rfc4594>.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006. Element (PCE)-Based Architecture", RFC 4655, DOI 10.17487/
RFC4655, August 2006,
<http://www.rfc-editor.org/info/rfc4655>.
[RFC6049] Morton, A. and E. Stephan, "Spatial Composition of [RFC6049] Morton, A. and E. Stephan, "Spatial Composition of
Metrics", RFC 6049, January 2011. Metrics", RFC 6049, DOI 10.17487/RFC6049, January 2011,
<http://www.rfc-editor.org/info/rfc6049>.
Authors' Addresses Authors' Addresses
Alia Atlas Alia Atlas
Juniper Networks Juniper Networks
10 Technology Park Drive 10 Technology Park Drive
Westford, MA 01886 Westford, MA 01886
USA USA
Email: akatlas@juniper.net Email: akatlas@juniper.net
skipping to change at page 10, line 17 skipping to change at page 10, line 42
Sunnyvale, CA 94089 Sunnyvale, CA 94089
USA USA
Email: jdrake@juniper.net Email: jdrake@juniper.net
Spencer Giacalone Spencer Giacalone
Unaffiliated Unaffiliated
Email: spencer.giacalone@gmail.com Email: spencer.giacalone@gmail.com
Dave Ward
Cisco Systems
170 West Tasman Dr.
San Jose, CA 95134
USA
Email: dward@cisco.com
Stefano Previdi Stefano Previdi
Cisco Systems Cisco Systems
Via Del Serafico 200 Via Del Serafico 200
Rome 00142 Rome 00142
Italy Italy
Email: sprevidi@cisco.com Email: sprevidi@cisco.com
Clarence Filsfils
Cisco Systems
Brussels
Belgium
Email: cfilsfil@cisco.com
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