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Versions: 00 01 02 03 draft-ietf-isis-te-metric-extensions

Networking Working Group                                 S. Previdi, Ed.
Internet-Draft                                       Cisco Systems, Inc.
Intended status: Standards Track                            S. Giacalone
Expires: August 29, 2013                                 Thomson Reuters
                                                                 D. Ward
                                                     Cisco Systems, Inc.
                                                                J. Drake
                                                                A. Atlas
                                                        Juniper Networks
                                                             C. Filsfils
                                                     Cisco Systems, Inc.
                                                       February 25, 2013


            IS-IS Traffic Engineering (TE) Metric Extensions
               draft-previdi-isis-te-metric-extensions-03

Abstract

   In certain networks, such as, but not limited to, financial
   information networks (e.g. stock market data providers), network
   performance criteria (e.g. latency) are becoming as critical to data
   path selection as other metrics.

   This document describes extensions to IS-IS TE [RFC5305] such that
   network performance information can be distributed and collected in a
   scalable fashion.  The information distributed using ISIS TE Metric
   Extensions can then be used to make path selection decisions based on
   network performance.

   Note that this document only covers the mechanisms with which network
   performance information is distributed.  The mechanisms for measuring
   network performance or acting on that information, once distributed,
   are outside the scope of this document.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

   In this document, these words will appear with that interpretation
   only when in ALL CAPS.  Lower case uses of these words are not to be
   interpreted as carrying RFC-2119 significance.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the



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   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on August 29, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.























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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  TE Metric Extensions to IS-IS  . . . . . . . . . . . . . . . .  4
   3.  Interface and Neighbor Addresses . . . . . . . . . . . . . . .  6
   4.  Sub TLV Details  . . . . . . . . . . . . . . . . . . . . . . .  6
     4.1.  Unidirectional Link Delay Sub-TLV  . . . . . . . . . . . .  6
     4.2.  Unidirectional Delay Variation Sub-TLV . . . . . . . . . .  7
     4.3.  Unidirectional Link Loss Sub-TLV . . . . . . . . . . . . .  8
     4.4.  Unidirectional Residual Bandwidth Sub-TLV  . . . . . . . .  9
     4.5.  Unidirectional Available Bandwidth Sub-TLV . . . . . . . . 10
   5.  Announcement Thresholds and Filters  . . . . . . . . . . . . . 10
   6.  Announcement Suppression . . . . . . . . . . . . . . . . . . . 11
   7.  Network Stability and Announcement Periodicity . . . . . . . . 11
   8.  Compatibility  . . . . . . . . . . . . . . . . . . . . . . . . 11
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 11
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 12
   11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
   12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     12.1. Normative References . . . . . . . . . . . . . . . . . . . 12
     12.2. Informative References . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13





























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1.  Introduction

   This document describes extensions to IS-IS Extended Reachability TLV
   defined in [RFC5305] (hereafter called "IS-IS TE Metric Extensions"),
   that can be used to distribute network performance information (such
   as link delay, delay variation, packet loss, residual bandwidth, and
   available bandwidth).

   In certain networks, such as, but not limited to, financial
   information networks (e.g. stock market data providers), network
   performance information (e.g. latency) is becoming as critical to
   data path selection as other metrics.

   The data distributed by the TE Metric Extensions proposed in this
   document is meant to be used as part of the operation of the routing
   protocol (e.g. by replacing cost with latency or considering
   bandwidth as well as cost), by enhancing Constrained-SPF (CSPF), or
   for other uses such as supplementing the data used by an ALTO server
   [I-D.ietf-alto-protocol].  With respect to CSPF, the data distributed
   by ISIS TE Metric Extensions can be used to setup, fail over, and
   fail back data paths using protocols such as RSVP-TE [RFC3209];
   [I-D.atlas-mpls-te-express-path] describes some methods for using
   this information to compute Label Switched Paths (LSPs) at the LSP
   ingress.

   Note that the mechanisms described in this document only disseminate
   performance information.  The methods for initially gathering that
   performance information, such as [RFC6375], or acting on it once it
   is distributed are outside the scope of this document.  Example
   mechanisms to measure latency, delay variation, and loss in an MPLS
   network are given in [RFC6374].  While this document does not specify
   how the performance information should be obtained, the measurement
   of delay SHOULD NOT vary significantly based upon the offered traffic
   load.  Thus, queuing delays SHOULD NOT be included in the delay
   measurement.  For links, such as Forwarding Adjacencies, care must be
   taken that measurement of the associated delay avoids significant
   queuing delay; that could be accomplished in a variety of ways,
   including either by measuring with a traffic class that experiences
   minimal queuing or by summing the measured link delays of the
   components of the link's path.


2.  TE Metric Extensions to IS-IS

   This document proposes new IS-IS TE sub-TLVs that can be announced in
   ISIS Extended Reachability TLV (TLV-22) to distribute network
   performance information.  The extensions in this document build on
   the ones provided in IS-IS TE [RFC5305] and GMPLS [RFC4203].



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   IS-IS Extended Reachability TLV 22 (defined in [RFC5305]), Inter-AS
   reachability information TLV 141 (defined in [RFC5316]) and MT-ISN
   TLV 222 (defined in [RFC5120]) have nested sub-TLVs which permit the
   TLVs to be readily extended.  This document proposes several
   additional sub-TLVs:

      Type          Value

      TBD1          Unidirectional Link Delay

      TBD2          Unidirectional Delay Variation

      TBD3          Unidirectional Packet Loss

      TBD4          Unidirectional Residual Bandwidth Sub TLV

      TBD5          Unidirectional Available Bandwidth Sub TLV

   As can be seen in the list above, the sub-TLVs described in this
   document carry different types of network performance information.
   The new sub-TLVs include a bit called the Anomalous (or "A") bit.
   When the A bit is clear (or when the sub-TLV does not include an A
   bit), the sub-TLV describes steady state link performance.  This
   information could conceivably be used to construct a steady state
   performance topology for initial tunnel path computation, or to
   verify alternative failover paths.

   When network performance violates configurable link-local thresholds
   a sub-TLV with the A bit set is advertised.  These sub-TLVs could be
   used by the receiving node to determine whether to fail traffic to a
   backup path, or whether to calculate an entirely new path.  From an
   MPLS perspective, the intent of the A bit is to permit LSP ingress
   nodes to:

   A) Determine whether the link referenced in the sub-TLV affects any
      of the LSPs for which it is ingress. If there are, then:

   B) Determine whether those LSPs still meet end-to-end performance
      objectives. If not, then:

   C) The node could then conceivably move affected traffic to a pre-
      established protection LSP or establish a new LSP and place the
      traffic in it.

   If link performance then improves beyond a configurable minimum value
   (reuse threshold), that sub-TLV can be re-advertised with the
   Anomalous bit cleared.  In this case, a receiving node can
   conceivably do whatever re-optimization (or failback) it wishes to do



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   (including nothing).

   Note that when a sub-TLV does not include the A bit, that sub-TLV
   cannot be used for failover purposes.  The A bit was intentionally
   omitted from some sub-TLVs to help mitigate oscillations.  See
   Section 5 for more information.

   Consistent with existing IS-IS TE specifications [RFC5305], the
   bandwidth advertisements defined in this draft MUST be encoded as
   IEEE floating point values.  The delay and delay variation
   advertisements defined in this draft MUST be encoded as integer
   values.  Delay values MUST be quantified in units of microseconds,
   packet loss MUST be quantified as a percentage of packets sent, and
   bandwidth MUST be sent as bytes per second.  All values (except
   residual bandwidth) MUST be calculated as rolling averages where the
   averaging period MUST be a configurable period of time.  See
   Section 5 for more information.


3.  Interface and Neighbor Addresses

   The use of TE Metric Extensions SubTLVs is not confined to the TE
   context.  In other words, IS-IS TE Metric Extensions SubTLVs defined
   in this document can also be used for computing paths in the absence
   of a TE subsystem.

   However, as for the TE case, Interface Address and Neighbor Address
   SubTLVs (IPv4 or IPv6) MUST be present.  The encoding is defined in
   [RFC5305] for IPv4 and in [RFC6119] for IPv6.


4.  Sub TLV Details

4.1.  Unidirectional Link Delay Sub-TLV

   This sub-TLV advertises the average link delay between two directly
   connected IS-IS neighbors.  The delay advertised by this sub-TLV MUST
   be the delay from the local neighbor to the remote one (i.e. the
   forward path latency).  The format of this sub-TLV is shown in the
   following diagram:











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      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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |A|   RESERVED  |    Delay      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       Delay                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      This sub-TLV has a type of TBD1.
      The length is 4.

   Where:

   "A" represents the Anomalous (A) bit.  The A bit is set when the
   measured value of this parameter exceeds its configured maximum
   threshold.  The A bit is cleared when the measured value falls below
   its configured reuse threshold.  If the A bit is clear, the sub-TLV
   represents steady state link performance.

   The "Reserved" field is reserved for future use.  It MUST be set to 0
   when sent and MUST be ignored when received.

   "Delay Value" is a 24-bit field carries the average link delay over a
   configurable interval in micro-seconds, encoded as an integer value.
   When set to 0, it has not been measured.  When set to the maximum
   value 16,777,215 (16.777215 sec), then the delay is at least that
   value and may be larger.

4.2.  Unidirectional Delay Variation Sub-TLV

   This sub-TLV advertises the average link delay variation between two
   directly connected IS-IS neighbors.  The delay variation advertised
   by this sub-TLV MUST be the delay from the local neighbor to the
   remote one (i.e. the forward path latency).  The format of this sub-
   TLV is shown in the following diagram:

      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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |A|  RESERVED   |Delay Variation|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       Delay Variation         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      This sub-TLV has a type of TBD2.
      The length is 4.

   Where:



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   "A" represents the Anomalous (A) bit.  The A bit is set when the
   measured value of this parameter exceeds its configured maximum
   threshold.  The A bit is cleared when the measured value falls below
   its configured reuse threshold.  If the A bit is clear, the sub-TLV
   represents steady state link performance.

   The "Reserved" field is reserved for future use.  It MUST be set to 0
   when sent and MUST be ignored when received.

   "Delay Variation" is a 24-bit field carries the average link delay
   variation over a configurable interval in micro-seconds, encoded as
   an integer value.  When set to 0, it has not been measured.  When set
   to the maximum value 16,777,215 (16.777215 sec), then the delay is at
   least that value and may be larger.

4.3.  Unidirectional Link Loss Sub-TLV

   This sub-TLV advertises the loss (as a packet percentage) between two
   directly connected IS-IS neighbors.  The link loss advertised by this
   sub-TLV MUST be the packet loss from the local neighbor to the remote
   one (i.e. the forward path loss).  The format of this sub-TLV is
   shown in the following diagram:

      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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |A|  RESERVED   |   Link Loss   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          Link Loss            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      This sub-TLV has a type of TBD3.
      The length is 4.

   Where:

   The "A" bit represents the Anomalous (A) bit.  The A bit is set when
   the measured value of this parameter exceeds its configured maximum
   threshold.  The A bit is cleared when the measured value falls below
   its configured reuse threshold.  If the A bit is clear, the sub-TLV
   represents steady state link performance.

   "Reserved" field is reserved for future use.  It MUST be set to 0
   when sent and MUST be ignored when received.

   "Link Loss" is a 24-bit field carries link packet loss as a
   percentage of the total traffic sent over a configurable interval.



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   The basic unit is 0.000003%, where (2^24 - 2) is 50.331642%.  This
   value is the highest packet loss percentage that can be expressed
   (the assumption being that precision is more important on high speed
   links than the ability to advertise loss rates greater than this, and
   that high speed links with over 50% loss are unusable).  Therefore,
   measured values that are larger than the field maximum SHOULD be
   encoded as the maximum value.  When set to a value of all 1s (2^24 -
   1), the link packet loss has not been measured.

4.4.  Unidirectional Residual Bandwidth Sub-TLV

   This TLV advertises the residual bandwidth between two directly
   connected IS-IS neighbors.  The residual bandwidth advertised by this
   sub-TLV MUST be the residual bandwidth from the system originating
   the sub-TLV to its neighbor.  The format of this sub-TLV is shown in
   the following diagram:

   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |     Length    |A|  RESERVED   |   Residual    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Bandwidth                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      This sub-TLV has a type of TBD4.
      The length is 5.

   Where:

   The "A" bit represents the Anomalous (A) bit.  The A bit is set when
   the measured value of this parameter exceeds its configured maximum
   threshold.  The A bit is cleared when the measured value falls below
   its configured reuse threshold.  If the A bit is clear, the sub-TLV
   represents steady state link performance.

   "Residual Bandwidth" is the residual bandwidth in IEEE floating point
   format in units of bytes per second.  The link may be a single link,
   forwarding adjacency [RFC4206], or bundled link.  For a link or
   forwarding adjacency, residual bandwidth is defined to be Maximum
   Link Bandwidth [RFC5305] minus the bandwidth currently allocated to
   RSVP-TE LSPs.  For a bundled link, residual bandwidth is defined to
   be the sum of the component link residual bandwidths.

   Note that although it may seem possible to calculate Residual
   Bandwidth using the existing sub-TLVs in [RFC5305], this is not a
   consistently reliable approach and hence the Residual Bandwidth sub-
   TLV has been added here.  For example, because the Maximum Reservable



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   Bandwidth [RFC5305] can be larger than the capacity of the link,
   using it as part of an algorithm to determine the value of the
   Maximum Link Bandwidth [RFC5305]minus the bandwidth currently
   allocated to RSVP-TE Label Switched Paths cannot be considered
   reliably accurate.

4.5.  Unidirectional Available Bandwidth Sub-TLV

   This TLV advertises the available bandwidth between two directly
   connected IS-IS neighbors.  The available bandwidth advertised in
   this sub-TLV MUST be the available bandwidth from the originating
   system to its neighbor.  The format of this sub-TLV is shown in the
   following diagram:

   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |     Length    |A|  RESERVED   |   Available   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Bandwidth                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      This sub-TLV has a type of TBD5.
      The length is 5.


   Where:

   The "A" bit represents the Anomalous (A) bit.  The A bit is set when
   the measured value of this parameter exceeds its configured maximum
   threshold.  The A bit is cleared when the measured value falls below
   its configured reuse threshold.  If the A bit is clear, the sub-TLV
   represents steady state link performance.

   "Available Bandwidth" is a field that carries the available bandwidth
   on a link, forwarding adjacency, or bundled link in IEEE floating
   point format with units of bytes per second.  For a link or
   forwarding adjacency, available bandwidth is defined to be residual
   bandwidth (see Section 4.4) minus the measured bandwidth used for the
   actual forwarding of non-RSVP-TE Label Switched Paths packets.  For a
   bundled link, available bandwidth is defined to be the sum of the
   component link available bandwidths.


5.  Announcement Thresholds and Filters

   The values advertised in all sub-TLVs MUST be controlled using an
   exponential filter (i.e. a rolling average) with a configurable



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   measurement interval and filter coefficient.

   Implementations are expected to provide separately configurable
   advertisement thresholds.  All thresholds MUST be configurable on a
   per sub-TLV basis.

   The announcement of all sub-TLVs that do not include the A bit SHOULD
   be controlled by variation thresholds that govern when they are sent.

   Sub-TLVs that include the A bit are governed by several thresholds.
   Firstly, a threshold SHOULD be implemented to govern the announcement
   of sub-TLVs that advertise a change in performance, but not an SLA
   violation (i.e. when the A bit is not set).  Secondly,
   implementations MUST provide configurable thresholds that govern the
   announcement of sub-TLVs with the A bit set (for the indication of a
   performance violation).  Thirdly, implementations SHOULD provide
   reuse thresholds.  These thresholds govern sub-TLV re-announcement
   with the A bit cleared to permit fail back.


6.  Announcement Suppression

   When link performance average values change, but fall under the
   threshold that would cause the announcement of a sub-TLV with the A
   bit set, implementations MAY suppress or throttle sub-TLV
   announcements.  All suppression features and thresholds SHOULD be
   configurable.


7.  Network Stability and Announcement Periodicity

   To mitigate concerns about stability, all values (except residual
   bandwidth) MUST NOT be instantaneous measurements.  The period to
   compute statistics, whether rolling average, rolling 98th percentile,
   or network custom, MUST be a configurable period of time.
   Announcements MUST also be able to be throttled using configurable
   inter-update throttle timers.  The minimum announcement periodicity
   is 1 announcement per second.


8.  Compatibility

   As per [RFC5305], unrecognized Sub-TLVs should be silently ignored


9.  Security Considerations

   This document does not introduce security issues beyond those



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   discussed in [RFC3630] and [RFC5329].


10.  IANA Considerations

   IANA maintains the registry for the sub-TLVs.  IS-IS TE Metric
   Extensions will require one new type code per sub-TLV defined in this
   document.


11.  Acknowledgements

   The authors would like to recognize Ayman Soliman and Les Ginsberg
   for their contributions.


12.  References

12.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, December 2001.

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630,
              September 2003.

   [RFC4203]  Kompella, K. and Y. Rekhter, "OSPF Extensions in Support
              of Generalized Multi-Protocol Label Switching (GMPLS)",
              RFC 4203, October 2005.

   [RFC4206]  Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP)
              Hierarchy with Generalized Multi-Protocol Label Switching
              (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005.

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120, February 2008.

   [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
              Engineering", RFC 5305, October 2008.

   [RFC5316]  Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS



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              Traffic Engineering", RFC 5316, December 2008.

   [RFC5329]  Ishiguro, K., Manral, V., Davey, A., and A. Lindem,
              "Traffic Engineering Extensions to OSPF Version 3",
              RFC 5329, September 2008.

   [RFC6119]  Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic
              Engineering in IS-IS", RFC 6119, February 2011.

   [RFC6374]  Frost, D. and S. Bryant, "Packet Loss and Delay
              Measurement for MPLS Networks", RFC 6374, September 2011.

12.2.  Informative References

   [I-D.atlas-mpls-te-express-path]
              Atlas, A., Drake, J., Giacalone, S., Ward, D., Previdi,
              S., and C. Filsfils, "Performance-based Path Selection for
              Explicitly Routed LSPs",
              draft-atlas-mpls-te-express-path-02 (work in progress),
              February 2013.

   [I-D.ietf-alto-protocol]
              Alimi, R., Penno, R., and Y. Yang, "ALTO Protocol",
              draft-ietf-alto-protocol-13 (work in progress),
              September 2012.

   [RFC6375]  Frost, D. and S. Bryant, "A Packet Loss and Delay
              Measurement Profile for MPLS-Based Transport Networks",
              RFC 6375, September 2011.


Authors' Addresses

   Stefano Previdi (editor)
   Cisco Systems, Inc.
   Via Del Serafico 200
   Rome  00191
   IT

   Email: sprevidi@cisco.com











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   Spencer Giacalone
   Thomson Reuters
   195 Broadway
   New York, NY  10007
   USA

   Email: Spencer.giacalone@thomsonreuters.com


   Dave Ward
   Cisco Systems, Inc.
   3700 Cisco Way
   SAN JOSE, CA  95134
   US

   Email: wardd@cisco.com


   John Drake
   Juniper Networks
   1194 N. Mathilda Ave.
   Sunnyvale, CA  94089
   USA

   Email: jdrake@juniper.net


   Alia Atlas
   Juniper Networks
   1194 N. Mathilda Ave.
   Sunnyvale, CA  94089
   USA

   Email: akatlas@juniper.net


   Clarence Filsfils
   Cisco Systems, Inc.
   Brussels
   Belgium

   Email: cfilsfil@cisco.com









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