ALTO Working Group                                                 Q. Wu
Internet-Draft                                                    Huawei
Intended status: Standards Track                                 Y. Yang
Expires: March 10, September 4, 2017                               Yale University
                                                                  Y. Lee
                                                                D. Dhody
                                                                  Huawei
                                                          S. Randriamasy
                                                         Nokia Bell Labs
                                                       September 6, 2016
                                                           March 3, 2017

                     ALTO Performance Cost Metrics
                 draft-ietf-alto-performance-metrics-00
                 draft-ietf-alto-performance-metrics-01

Abstract

   Cost Metric is a basic concept in Application-Layer Traffic
   Optimization (ALTO).  It is used in both the Cost Map Service and the
   Endpoint Cost Service.  Future extensions to ALTO may also use Cost
   Metric.

   Different applications may benefit from different Cost Metrics.  For
   example, a Resource Consumer may prefer Resource Providers that have
   offers a low delay delivery to the Resource Consumer.  However the
   base ALTO protocol [ALTO] has documented only a one single cost metric,
   i.e., the generic "routingcost" metric (Sec. 14.2 of ALTO base
   specification [ALTO]).

   In this

   This document, we proposes a set of Cost Metrics, derived and aggregated
   from routing protocols with different granularity and scope, such as
   BGP-LS,OSPF-TE and ISIS-TE, or from end to end traffic management tool.  We
   tools.  It currently document 11 new documents Network Performance Metric to
   measure Cost Metrics
   reporting on network delay, jitter, packet loss, hop count, and
   bandwidth.
   The  These metrics documented in this document provide a relatively
   comprehensive set of Cost Metrics for may be exposed by an ALTO and Server to allow
   applications to determine "where" to connect based on end to end network
   performance criteria.  Additional Cost Metrics such as financial cost metrics involving ISP specific
   considerations or other network technologies may be documented in other documents.
   further versions of this draft.

   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].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   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
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 10, September 4, 2017.

Copyright Notice

   Copyright (c) 2016 2017 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
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Data sources,  Challenges on data sources and computation of defined cost ALTO
       performance metrics . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  Data sources  . . . . . . . . . . . . . . . . . . . . . .   5
     2.2.  Computation of ALTO performance metrics . . . . . . . . . . . . . . . . .   5
   3.  Cost Metric: OWDelay POWDelay . . . . . . . . . . . . . . . . . . . .   6
   4.  Cost Metric: PDV RTT  . . . . . . . . . . . . . . . . . . . . . .   8
   5.  Cost Metric: Packet Loss PDV  . . . . . . . . . . . . . . . . . . . . . .   9
   6.  Cost Metric: Hop Count  . . . . . . . . . . . . . . . . . . .  11
   7.  Cost Metric: Bandwidth  . Packet Loss  . . . . . . . . . . . . . . . . . .  13
   8.  Traffic Engineering Performance Cost Metric: Maximum Bandwidth  . . . . . . . Metrics  . . . . . . . .  14
   9.  15
     8.1.  Cost Metric: Link Maximum Reservable Bandwidth  . . . . . . . . . .  16
   10. Cost Metric: RTT  . . . . . . . . . . . . . . . . . . . . . .  18
   11.
     8.2.  Cost Metric: Link Residue Bandwidth . . . . . . . . . . . . . . .  20
   12.  17
     8.3.  Cost Metric: Link Available Bandwidth . . . . . . . . . . . . . .  22
   13.  19
     8.4.  Cost Metric: Link Utilized Bandwidth  . . . . . . . . . . . . . . .  24
   14.  21
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  26
   15.  23
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  27
   16.  24
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  27
     16.1.  24
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  27
     16.2.  24
     11.2.  Informative References . . . . . . . . . . . . . . . . .  28  26
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  29  26

1.  Introduction

   Cost Metric is a basic concept in Application-Layer Traffic
   Optimization (ALTO).  It is used in both the Cost Map Service and the
   Endpoint Cost Service.  In particular, applications may benefit from
   knowing network performance measured on several Cost Metrics.  For
   example, a more delay sensitive application may focus on latency, and
   a more bandwidth-sensitive application may focus on available
   bandwidth.

   The objective of this

   This document is to introduce 11 introduces a set new performance cost metrics, listed in Table 1,
   to support the aforementioned applications and allow applications them to
   determine "where" to connect based on end to end network performance criteria.
   Hence, this document extends the base ALTO protocol [ALTO], which
   defines only a single cost metric, i.e., the generic "routingcost"
   metric (Sec. 14.2 of ALTO base specification [ALTO]).

      +-----------+--------------+------------------------+
      | Namespace

+----------+--------------+---------------------------------------------+
|Namespace | Property     | Reference                                   |
      +-----------+--------------+------------------------+
+----------+--------------+---------------------------------------------+
|          |  owdelay     | [RFCxxxx], See Section 3 3,[RFC2679] Section 3.6         |
|          |  pdv   rtt        | [RFCxxxx], See Section 4,[RFC2681] Section 4 2.6         |
|          | pktloss   pdv        | [RFCxxxx], See Section 5 5,[RFC3393] Section 2.6         |
|          | hopcount     | [RFCxxxx], See Section 6 6,[RFC7285]                     |
|          | bandwidth pktloss      | [RFCxxxx], See Section 7   |
      |           | maxbw        | [RFCxxxx], 7,[RFC7680] Section 8 2.6         |
|          | maxresbw     | [RFCxxxx], See Section 9   |
      |           |  rtt         | [RFCxxxx], 8.1,[RFC5305] Section 10 3.5       |
|          | residbw      | [RFCxxxx], See Section 11 8.2,[RFC7810] Section 4.5       |
|          | availbw      | [RFCxxxx], See Section 12 8.3,[RFC7810] Section 4.6       |
|          | utilbw       | [RFCxxxx], See Section 13 8.4,[RFC7810 Section 4.7        |
      +-----------+--------------+------------------------+
+----------+--------------+---------------------------------------------+
                       Table 1.

   An ALTO server may provide a subset

   The purpose of the cost this draft is to list the metrics documented likely to be exposed
   to ALTO Clients, including those already specified in other
   standardization groups and as such it does not claim novelty on all
   the specified metrics.  Some metrics may have values produced by
   explicitely specified measurement methods such as those specified in
   IPPM, some may be ISP dependent such as those registered in ISIS or
   OSPF-TE.  In this case, this document will refer to the relevant
   specifications.

   An ALTO server may provide a subset of the cost metrics described in
   this document.  These cost metrics can be retrieved and aggregated
   from routing protocol protocols or other traffic measurement management tool tools
   (See Figure 1).  Note that these cost metrics are optional metrics and Not not
   all these cost metrics them need to be exposed to the application. applications.  If some of these cost metrics have are subject to
   privacy concern, concerns, the alto ALTO server should not provide them to the
   client.

   +--------+   +--------+  +--------+
   | Client |   | Client |  | Client |
   +----^---+   +---^----+  +---^----+
        |           |           |
        +-----------|-----------+
              NBI   |ALTO protocol
                    |
                    |
                 +--+-----+  retrieve       +---------+
                 |  ALTO  |<----------------| Routing |
                 | Server |  and aggregation|         |
                 |        |<-------------+  | Protocol|
                 +--------+              |  +---------+
                                         |
                                         |  +---------+
                                         |  |Management
                                         ---|         |
                                            |  Tool   |
                                            +---------+
                    Figure 1.End to End Path Cost Metrics Exposing

   When an ALTO server supports a cost metric defined in this document,
   the server
   it SHOULD announce the this metric in its IRD.

   The definitions of a set

   Additionally, further versions of cost metrics can allow us this document may define network
   metric values that stem from both measurements and provider policy as
   for example, many end to extend the end path bandwidth related ALTO base protocol (e.g., allowing output and constraints use
   different cost metrics), but metrics.
   ALTO may convey such extensions are information, not in available via 3rd party
   measurement tools.  Besides, IPPM informational RFC 5136 points the scope of
   this document.

   One challenge
   difficulty to have a unified nomenclature for network capacity
   related measurements.

   As for the reliability and trust in describing the metrics is that exposed metric values,
   applications will rapidly give up using ALTO-based guidance if they
   feel the exposed information does not preserve their performance metrics
   often depend on configuration parameters.  For example,
   level or even degrades it.

   Following the ALTO base protocol, this document uses JSON to specify
   the value type of
   packet loss rate depends each defined metric.  See [RFC4627] for JSON data
   type specification.

2.  Challenges on the measurement interval data sources and varies over
   time.  To handle this issue, computation of ALTO performance
    metrics

2.1.  Data sources

   An ALTO server may collect needs data on time
   periods covering sources to compute the past, present or only collect data on present
   time.  The ALTO may further aggregate these data to provide an
   abstract and unified view that can be more useful to applications.
   To make the ALTO client understand whether the performance data is
   past data or present data, the ALTO server needs to expose to the
   client the validity period of each performance metric.

   Following the ALTO base protocol, this document uses JSON to specify
   the value type of each defined metric.  See [RFC4627] for JSON data
   type specification.

2.  Data sources, computation of defined cost metrics

   The cost metrics described in this document are similar, in that they
   may use similar data sources and have similar issues in their
   calculation.  Hence, instead of specifying such issues for each
   metric individually, we specify the common issue in this section.

2.1.  Data sources

   An ALTO server needs data sources to compute the cost metrics
   described in this document.  This document does not define the exact cost metrics
   described in this document.  This document does not define the exact
   data sources.  For example, the ALTO server may use log servers or
   the OAM system as its data source [ALTO-DEPLOYMENT].  In particular,
   the cost metrics defined in this document can be computed using
   routing systems as the data sources.  Mechanisms defined in
   [RFC3630], [RFC3784], [OSPF-TE], [ISIS-TE], [BGP-LS] and [BGP-PM]
   that allow an ALTO Server to retrieve and derive the necessary
   information to compute the metrics that we described describe in this document.

   One challenge lies in the data sources originating the ALTO metric
   values.  The very purpose of ALTO is to guide application traffic
   with provider network centric information that may be exposed to ALTO
   Clients in the form of network performance metric values.  Not all of
   them metrics have values produced by standardized measurement methods
   or routing protocols.  Some of them involve provider-centric policy
   considerations.  Some of them may describe wireless or cellular
   networks.  To reliably guide users and applications while preserving
   provider privacy, ALTO performance metric values may also add
   abstraction to measurements or provide unitless performance scores.

2.2.  Computation of ALTO performance metrics

   An

   The metric values exposed by an ALTO server processes may result from
   additional processing on measurements from data sources to compute
   exposed metrics.  It  This may need performance invlove data processing tasks such as
   aggregating the results across multiple systems, removing outliers,
   and creating additional statistics.

   One specific challenge in deriving describing the metrics in this document is that these performance metrics
   often depend on some configuration parameters.  For example, the value of
   packet loss rate depends on the measurement interval and varies over
   time.  If the  To handle this issue, an ALTO server
   uses aforementioned routing protocol based mechanisms as data
   sources, then the measurement interval may be preconfigured by the
   routing protocol.  For example, Section 5 of [ISIS-TE] defines a
   default measurement interval of 30 seconds.  This document uses the
   term Measurement Interval to refer to the measurement interval used
   by the collect data sources.  In on time
   periods covering the [ISIS-TE] case, it is a measurement
   interval set by routing protocol. past and present or only collect data on present
   time.  The Measurement Interval(s) of the ALTO server may further aggregate these data sources to provide an
   abstract and unified view that can be different from the interval that this document
   derives the metric, e.g., the interval used by this document is
   multiple of measurement interval of more useful to applications.
   To make the data sources.  Hence, an ALTO
   server needs client better understand how to resolve use these
   performance data, the mismatch, when it happens.

   Another issue of converting from data source measurements to ALTO
   exposed metric values is that server may provide the measurement results that client with the ALTO
   Server retrieves may be defined for only links, and hence,
   validity period of the server
   will need exposed metric values.

   Another challenge relates to compose the link metrics availability of end to obtain end path metrics used in
   services such
   values for certain metrics.  Applications value information relating
   to bandwidth availability where as the Cost Map Service.  In this definition, we define
   the bandwidth related metrics to can
   often be independent of only measured at the link or path, considering level.  This document specifies a
   set of link-level bandwidth related values that
   future may be exposed as
   such by an ALTO extensions server.  The server may define link-based services, also expose other metrics
   derived from their aggregation and hence having different levels of
   endpoint granularity, e.g. link endpoints or session endpoints.  The
   metric specifications may also expose the
   defined metrics should still be usable. utilised aggregation laws.

3.  Cost Metric: OWDelay POWDelay

   Metric name:

      Periodic One Way Delay

   Metric Description:

      To specify spatial and temporal aggregated delay of a stream of
      packets exchanged between the specified source and destination or
      the time that the packet spends to travel from source to
      destination.  The spatial aggregation unit level is specified in the
      query context (e.g., PID to PID, or endpoint to endpoint); and the
      temporal unit is specified as the measurement interval in the
      query context. endpoint).

   Method of Measurement or Calculation:

      See section 8.3 of [I-D.ietf-ippm-initial-registry] for
      Measurement Method.

   Units of Measurement:

      See section 7.4.4 of [I-D.ietf-ippm-initial-registry] for
      Measurement Unit.  The unit is expressed in seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 8.3.5 of [I-D.ietf-ippm-initial-registry] for
      Measurement Timing.

   Use and Applications:

      This is intended to be a constraint attribute value.  A Cost Mode
      is encoded as a US-ASCII string.  The Metric value Type is a
      single 'JSONNumber' type value containing a non-negative integer
      component that may be followed by an exponent part.

      This metric could be used as a cost metric constraint attribute
      used either together with cost metric attribute 'routingcost' or
      on its own or as a returned cost metric in the response.

 Example 1: Delay value on source-destination endpoint pairs
  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

 {
   "cost-type": {"cost-mode" : "numerical",
                 "cost-metric" : "delay"},
   "endpoints" : {
     "srcs": [ "ipv4:192.0.2.2" ],
     "dsts": [
       "ipv4:192.0.2.89",
       "ipv4:198.51.100.34",
       "ipv6:2000::1:2345:6789:abcd"
     ]
   }
 }

 HTTP/1.1 200 OK
 Content-Length: TBA
 Content-Type: application/alto-endpointcost+json
 {
   "meta" :{
     "cost-type": {"cost-mode" : "numerical",
                   "cost-metric" : "delay"
      }
    },
     "endpoint-cost-map" : {
       "ipv4:192.0.2.2": {
         "ipv4:192.0.2.89"    : 10,
         "ipv4:198.51.100.34" : 20,
         "ipv6:2000::1:2345:6789:abcd"  : 30,
     }
   }
 }

4.  Cost Metric: PDV

   Metric name:

      Pakcet Delay Variation

   Metric Description:

      To specify spatial and temporal aggregated jitter (packet delay
      variation) with respect to the minimum delay observed on the
      stream over the specified source and destination.  The spatial
      aggregation unit is specified in the query context (e.g., PID to
      PID, or endpoint to endpoint); and the temporal unit is specified
      as the measurement interval in the query context.

   Method of Measurement or Calculation:

      See section 5.3 of [I-D.ietf-ippm-initial-registry] for
      Measurement Method.

   Units of Measurement:

      See section 5.4.4 of [I-D.ietf-ippm-initial-registry] for
      Measurement Unit.  The unit is expressed in seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 5.3.5 of [I-D.ietf-ippm-initial-registry] for
      Measurement Timing.

   Measurement Timing:Use and Applications:

      See section 3 for use and application.

  Example 2: Delayjitter value on source-destination endpoint pairs
  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

  {
    "cost-type": {"cost-mode" : "numerical",
     "cost-metric" : "delayjitter"},
    "endpoints" : {
      "srcs": [ "ipv4:192.0.2.2" ],
      "dsts": [
        "ipv4:192.0.2.89",
        "ipv4:198.51.100.34",
        "ipv6:2000::1:2345:6789:abcd"
      ]
    }
  }
  HTTP/1.1 200 OK
   Content-Length: TBA
   Content-Type: application/alto-endpointcost+json
  {
    "meta": {
             "cost type": {
             "cost-mode": "numerical",
             "cost-metric":"delayjitter"
      }
     },
    "endpoint-cost-map": {
             "ipv4:192.0.2.2": {
             "ipv4:192.0.2.89"    : 0
             "ipv4:198.51.100.34" : 1
             "ipv6:2000::1:2345:6789:abcd"  : 5
           }
        }
     }

5.  Cost Metric: Packet Loss

   Metric name:

      Packet loss

   Metric Description:

      To specify spatial and temporal aggregated packet loss over the
      specified source and destination.  The spatial aggregation unit is
      specified in the query context (e.g., PID to PID, or endpoint to
      endpoint); and the temporal unit is specified as the measurement
      interval in the query context.

   Method of Measurement or Calculation:

      See section 2.2, Computation of metrics.

   Units of Measurement:

      See section 8.4.3 of [I-D.ietf-ippm-initial-registry] for
      Measurement Unit.  The unit is percentile. expressed in seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 8.3.5 of [I-D.ietf-ippm-initial-registry] for
      Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

      The Metric value Type is a single 'JSONNumber' type value
      containing a non-negative integer component that may be followed
      by an exponent part.  The Cost Mode is encoded as a US-ASCII
      string.

      This metric could be used as a cost metric constraint attribute
      used either together with cost metric attribute 'routingcost' or
      on its own or as a returned cost metric in the response.

 Example 3: pktloss 1: Delay value on source-destination endpoint pairs

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

 {
   "cost-type": {"cost-mode" : "numerical",
                 "cost-metric" : "pktloss"}, "powdelay"},
   "endpoints" : {
     "srcs": [ "ipv4:192.0.2.2" ],
     "dsts": [
       "ipv4:192.0.2.89",
       "ipv4:198.51.100.34",
       "ipv6:2000::1:2345:6789:abcd"
     ]
   }
 }

 HTTP/1.1 200 OK
 Content-Length: TBA
 Content-Type: application/alto-endpointcost+json
 {
      "meta": {
                 "cost type": {
               "cost-mode":
   "meta" :{
     "cost-type": {"cost-mode" : "numerical",
               "cost-metric":"pktloss"}
                   "cost-metric" : "powdelay"
      }
    },
     "endpoint-cost-map":
     "endpoint-cost-map" : {
       "ipv4:192.0.2.2": {
         "ipv4:192.0.2.89"    : 0,
             "ipv4:198.51.100.34": 1, 10,
         "ipv4:198.51.100.34" : 20,
         "ipv6:2000::1:2345:6789:abcd"  : 2, 30,
     }
   }
 }

6.

4.  Cost Metric: Hop Count

   The metric hopcount is mentioned in [ALTO] as an example.  This
   section further clarifies its properties. RTT

   Metric name:

      Hop count

      Round Trip Delay

   Metric Description:

      To specify the number of hops in the path spatial and temporal aggregated round trip delay
      between the specified source
      endpoint and destination or the time that the
      packet spends to travel from source to destination endpoint. and then from
      destination to source.  The hop count spatial aggregation level is a basic
      measurement of distance specified
      in a network and can be exposed as Router
      Hops, IP hops the query context (e.g., PID to PID, or other hops in direct relation endpoint to the routing
      prtocols originating this information. it might also result from
      the aggregation of such information. endpoint).

   Method of Measurement or Calculation:

      See section 2.2, Computation 4.3 of metrics. [I-D.ietf-ippm-initial-registry] for
      Measurement Method.

   Units of Measurement:

      See section 4.4.3 of [I-D.ietf-ippm-initial-registry] for
      Measurement Unit.  The unit is integer number. expressed in seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 4.3.5 of [I-D.ietf-ippm-initial-registry] for
      Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 4: hopcount

 Example 7: Round Trip Delay value on source-destination endpoint pairs

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

 {
   "cost-type": {"cost-mode" : "numerical",
                 "cost-metric" : "hopcount"}, "rtt"},
   "endpoints" : {
     "srcs": [ "ipv4:192.0.2.2" ],
     "dsts": [
       "ipv4:192.0.2.89",
       "ipv4:198.51.100.34",
       "ipv6:2000::1:2345:6789:abcd"
     ]
   }
 }

 HTTP/1.1 200 OK
 Content-Length: TBA
 Content-Type: application/alto-endpointcost+json
 {
      "meta": {
                 "cost type": {
               "cost-mode":
   "meta" :{
     "cost-type": {"cost-mode" : "numerical",
               "cost-metric":"hopcount"}
                   "cost-metric" : "rtt"
      }
    },
     "endpoint-cost-map":
     "endpoint-cost-map" : {
       "ipv4:192.0.2.2": {
         "ipv4:192.0.2.89"    : 5,
             "ipv4:198.51.100.34": 4,
         "ipv4:198.51.100.34" : 3,
         "ipv6:2000::1:2345:6789:abcd"  : 2,
     }
   }
 }

7.

5.  Cost Metric: Bandwidth PDV

   Metric name:

      Bandwidth

      Packet Delay Variation

   Metric Description:

      To specify spatial and temporal aggregated bandwidth jitter (packet delay
      variation) with respect to the minimum delay observed on the
      stream over the specified source and destination.  The spatial
      aggregation unit level is specified in the query context (e.g., PID to
      PID, or endhost endpoint to
      endhost); and the temporal unit is specified as the measurement
      interval in the query context.

      This is just a definition of a class of cost metric 'bandwidth'.
      The use of this cost metric is always in conjunction with what it
      represents, which could be Max Bandwidth (maxbw), Residual
      Bandwidth (residuebw) etc. endpoint).

   Method of Measurement or Calculation:

      See section 2.2, Computation 5.3 of metrics. [I-D.ietf-ippm-initial-registry] for
      Measurement Method.

   Units of Measurement:

      See section 5.4.4 of [I-D.ietf-ippm-initial-registry] for
      Measurement Unit.  The units are bytes per second. unit is expressed in seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 5.3.5 of [I-D.ietf-ippm-initial-registry] for
      Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

8.

  Example 2: Delay jitter value on source-destination endpoint pairs

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

  {
    "cost-type": {"cost-mode" : "numerical",
     "cost-metric" : "delayjitter"},
    "endpoints" : {
      "srcs": [ "ipv4:192.0.2.2" ],
      "dsts": [
        "ipv4:192.0.2.89",
        "ipv4:198.51.100.34",
        "ipv6:2000::1:2345:6789:abcd"
      ]
    }
  }
  HTTP/1.1 200 OK
   Content-Length: TBA
   Content-Type: application/alto-endpointcost+json
  {
    "meta": {
             "cost type": {
             "cost-mode": "numerical",
             "cost-metric":"delayjitter"
      }
     },
    "endpoint-cost-map": {
             "ipv4:192.0.2.2": {
             "ipv4:192.0.2.89"    : 0
             "ipv4:198.51.100.34" : 1
             "ipv6:2000::1:2345:6789:abcd"  : 5
           }
        }
     }

6.  Cost Metric: Maximum Bandwidth

   Metric name:

      Maximum Bandwidth

   Metric Description:

      To specify spatial and temporal maximum bandwidth over the
      specified source and destination.  The values correspond to the
      maximum bandwidth that can be used (motivated from RFC 3630 Sec.
      2.5.6.). Hop Count

   The spatial aggregation unit metric hopcount is specified mentioned in [ALTO] as an example.  This
   section further clarifies its properties.

   Metric name:

      Hop count

   Metric Description:

      To specify the number of hops in the query
      context (e.g., PID to PID, or endhost to endhost); path between the source
      endpoint and the
      temporal unit destination endpoint.  The hop count is specified as the a basic
      measurement interval of distance in a network and can be exposed as Router
      Hops, IP hops or other hops in direct relation to the
      query context. routing
      protocols originating this information.  It might also result from
      the aggregation of such information.

   Method of Measurement or Calculation:

      See section 2.2, Computation of metrics.

   Units of Measurement:

      See definition for the Bandwidth Cost Metric.

      The unit is integer number.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph for Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 5: maxbw 4: hopcount value on source-destination endpoint pairs

  POST/ endpointcost/lookup

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

    {
      "cost-type": { "cost-mode": {"cost-mode" : "numerical",
     "cost-metric":  "maxbw"},
     "endpoints":
       "cost-metric" : "hopcount"},
      "endpoints" : {
        "srcs": [ "ipv4 : 192.0.2.2" "ipv4:192.0.2.2" ],
        "dsts": [
          "ipv4:192.0.2.89",
          "ipv4:198.51.100.34",
          "ipv6:2000::1:2345:6789:abcd"
        ]
      }
    }
  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
  {
      "meta": {
             "cost-type":
                 "cost type": {
               "cost-mode": "numerical",
             "cost-metric": "maxbw"
               "cost-metric":"hopcount"}
         }
      },
     "endpoint-cost-map": {
             "ipv4:192.0.2.2": {
            "ipv4:192.0.2.89":    0,
            "ipv4:198.51.100.34"
             "ipv4:192.0.2.89"   : 2000,
            "ipv6:2000::1:2345:6789:abcd":  5000, 5,
             "ipv4:198.51.100.34": 3,
             "ipv6:2000::1:2345:6789:abcd" : 2,
                               }
               }
   }

9.

7.  Cost Metric: Maximum Reservable Bandwidth Packet Loss

   Metric name:

      Maximum Reservable Bandwidth

      Packet loss

   Metric Description:

      To specify spatial and temporal maximum reservable bandwidth aggregated packet loss over the
      specified source and destination.  The value is corresponding
      to the maximum bandwidth that can be reserved (motivated from RFC
      3630 Sec.  2.5.7.).  The spatial aggregation unit level
      is specified in the query context (e.g., PID to PID, or endpoint
      to endpoint); and
      the temporal unit is specified as the measurement interval in the
      query context. endpoint).

   Method of Measurement or Calculation:

      See section 2.2, Computation 2.6 of metrics. [RFC7680] for Measurement Method.

   Units of Measurement:

      See definition of the Bandwidth Cost Metric.

      The unit is percentile.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 2 and section3 of [RFC7680] for Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 6: maxresbw 3: pktloss value on source-destination endpoint pairs

  POST/ endpointcost/lookup

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

    {
      "cost-type" { "cost-mode":
      "cost-type": {"cost-mode" : "numerical",
      "cost-metric":  "maxresbw"},
      "endpoints":
       "cost-metric" : "pktloss"},
      "endpoints" : {
        "srcs": [ "ipv4 : 192.0.2.2" "ipv4:192.0.2.2" ],
        "dsts": [
          "ipv4:192.0.2.89",
          "ipv4:198.51.100.34",
          "ipv6:2000::1:2345:6789:abcd"
        ]
      }
    }
  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
  {
      "meta": {
             "cost-type":
                 "cost type": {
               "cost-mode": "numerical",
             "cost-metric": "maxresbw"
               "cost-metric":"pktloss"}
         }
      },
    " endpoint-cost-map":
     "endpoint-cost-map": {
            "ipv4:192.0.2.2"
             "ipv4:192.0.2.2": {
             "ipv4:192.0.2.89"   : 0,
             "ipv4:198.51.100.34": 2000,
            "ipv6:2000::1:2345:6789:abcd":  5000, 1,
             "ipv6:2000::1:2345:6789:abcd" : 2,
                               }
               }
   }

10.

8.  Traffic Engineering Performance Cost Metrics

   This section introduces ALTO network performance metrics that may be
   aggregated from network metrics measured on links and specified in
   other documents.  In particular, the bandwidth related metrics
   specified in this section are only available through link level
   measurements.  For some of these metrics, the ALTO Server may further
   expose aggregated values while specifying the aggregation laws.

8.1.  Cost Metric: RTT Link Maximum Reservable Bandwidth

   Metric name:

      Round Trip Delay

      Maximum Reservable Bandwidth

   Metric Description:

      To specify spatial and temporal aggregated round trip delay
      between maximum reservable bandwidth over
      the specified source and destination or destination.  The value is corresponding
      to the time maximum bandwidth that the
      packet spends to travel from source to destination and then can be reserved (motivated from
      destination to source. RFC
      3630 Sec. 2.5.7.).  The spatial aggregation unit is specified in
      the query context (e.g., PID to PID, or endpoint to endpoint);
      and the temporal unit is specified as the measurement interval in
      the query context. endpoint).

   Method of Measurement or Calculation:

      Maximum Reserveable Bandwidth is the bandwidth measured between
      two directly connected IS-IS neighbors or OSPF neighbor, See
      section 2.2, Computation 3.5 of metrics. [RFC5305] for Measurement Method.

   Units of Measurement:

      See definition for the bandwidth Cost Metric.

      The unit of measurement is byte per seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 3.5 of [RFC5305] and section 5 of [RFC7810] for
      Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 7: Round Trip Delay 6: maxresbw value on source-destination endpoint pairs
  POST /endpointcost/lookup

  POST/ endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

    {
   "cost-type": {"cost-mode" :
      "cost-type" { "cost-mode":  "numerical",
                 "cost-metric" : "rtt"},
   "endpoints" :
      "cost-metric":  "maxresbw"},
      "endpoints":  {
        "srcs": [ "ipv4:192.0.2.2" "ipv4 : 192.0.2.2" ],
        "dsts": [
          "ipv4:192.0.2.89",
          "ipv4:198.51.100.34",
          "ipv6:2000::1:2345:6789:abcd"
        ]
      }
    }
  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
  {
   "meta" :{
      "meta": {
             "cost-type": {"cost-mode" : {
             "cost-mode": "numerical",
                   "cost-metric" : "rtt"
             "cost-metric": "maxresbw"
             }
      },
     "endpoint-cost-map" :
    " endpoint-cost-map": {
       "ipv4:192.0.2.2":
            "ipv4:192.0.2.2" {
            "ipv4:192.0.2.89" : 4,
         "ipv4:198.51.100.34" : 3,
         "ipv6:2000::1:2345:6789:abcd"  : 2,    0,
            "ipv4:198.51.100.34": 2000,
            "ipv6:2000::1:2345:6789:abcd":  5000,
                              }
             }
  }

11.

8.2.  Cost Metric: Link Residue Bandwidth

   Metric name:

      Residue Bandwidth

   Metric Description:

      To specify spatial and temporal residual bandwidth over the
      specified source and destination.  The value is calculated by
      subtracting tunnel reservations from Maximum Bandwidth (motivated
      from [RFC7810], Sec.4.5.).  The spatial aggregation unit is
      specified in the query context (e.g., PID to PID, or endpoint to
      endpoint); and the temporal unit is specified as the measurement
      interval in the query context.
      endpoint).

   Method of Measurement or Calculation:

      Residue Bandwidth is the Unidirectional Residue bandwidth measured
      between two directly connected IS-IS neighbors or OSPF neighbor,
      See section 2.2, Computation 4.5 of metrics. [RFC7810] for Measurement Method.

   Units of Measurement:

      See definition

      The unit of the general Bandwidth. measurement is byte per seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 5 of [RFC7810] for Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 8: residuebw value on source-destination endpoint pairs

  POST/ endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

    {
     "cost-type": { "cost-mode":  "numerical",
     "cost-metric":  "residubw"},
     "endpoints":  {
       "srcs": [ "ipv4 : 192.0.2.2" ],
       "dsts": [
         "ipv4:192.0.2.89",
         "ipv4:198.51.100.34",
         "ipv6:2000::1:2345:6789:abcd"
       ]
     }
  }

  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
  {
     "meta": {
            "cost-type" {
            "cost-mode": "numerical",
            "cost-metric": "residubw"
          }
      },
  "endpoint-cost-map" {
           "ipv4:192.0.2.2" {
           "ipv4:192.0.2.89" :    0,
           "ipv4:198.51.100.34": 2000,
           "ipv6:2000::1:2345:6789:abcd":  5000,
                         }
          }
  }

12.

8.3.  Cost Metric: Link Available Bandwidth

   Metric name:

      Available Bandwidth

   Metric Description:

      To specify spatial and temporal availaible bandwidth over the
      specified source and destination.  The value is calculated by
      subtracting the measured bandwidth used for the actual forwarding
      of best effort traffic from Residue Bandwidth (motivated from
      [RFC7810], Sec.4.6.).  The spatial aggregation unit is specified
      in the query context (e.g., PID to PID, or endpoint to endpoint);
      and the temporal unit level is specified as the measurement interval
      in the query context. context (e.g., PID to PID, or endpoint to endpoint).

   Method of Measurement or Calculation:

      Available bandwidth is the Unidirectional Available bandwidth
      measured between two directly connected IS-IS neighbors or OSPF
      neighbor, See section 2.2, Computation 4.6 of metrics. [RFC7810] for Measurement Method.

   Units of Measurement:

      See definition

      The unit of the general Bandwidth. measurement is byte per seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      See section 2.1, second paragraph 5 of [RFC7810] for Measurement Timing.

   Use and Applications:

      See section 3 for use and application.  Besides, knowledge about
      available bandwidth is essential for applications to distribute or
      schedule their transmissions.  The example below illustrates how
      this metric is provided in the form of an ALTO calendar, as
      specified in [XXXX] to help deciding "where" and "when" to
      transmit.

  Example 9: availbw value on source-destination endpoint pairs

  This example assumes that the ALTO Server provides the values for
  metric "availbw" in the form of an ALTO calendar and declares it
  in its IRD.

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

    {
     "cost-type": { "cost-mode":  "numeric",  "numerical",
                    "cost-metric":  "availbw"},
     "calendared" : [true],
     "endpoints":  {
        "srcs": [ "ipv4 : 192.0.2.2" ],
        "dsts": [
          "ipv4:192.0.2.89",
          "ipv4:198.51.100.34",
          "ipv6:2000::1:2345:6789:abcd"
        ]
     }
       }

  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
  {
     "meta": {
           "cost-type": {
               "cost-mode": "numeric", "numerical", "cost-metric": "availbw"
           }
           "calendar-response-attributes" : [
              "calendar-start-time" : Tue, 1 Mar 2017 13:00:00 GMT,
              "time-interval-size" : "1 hour",
              "numb-intervals" : 8
         ]
     },

     "endpoint-cost-map": {
             "ipv4:192.0.2.2" {
             "ipv4:192.0.2.89" : [6,5,7,8,4,10,7,6],
             "ipv4:198.51.100.34" : [7,4,6,8,5,9,6,7],
             "ipv6:2000::1:2345:6789:abcd" : [7,6,8,5,7,9,6,8],
             }
           }
  }

13.

8.4.  Cost Metric: Link Utilized Bandwidth

   Metric name:

      Utilized Bandwidth

   Metric Description:

      To specify spatial and temporal utilized bandwidth over the
      specified source and destination.  The value is corresponding to
      the actual measured bandwidth used for all traffic (motivated from
      [RFC7810], Sec.4.7.).  The spatial aggregation unit level is specified
      in the query context (e.g., PID to PID, or endpoint to endpoint);
      and the temporal unit is specified as the measurement interval in
      the query context. endpoint).

   Method of Measurement or Calculation:

      Link Utilizated bandwidth is Unidirectional utilization bandwidth
      measured between two directly connected IS-IS neighbors or OSPF
      neighbor, See section 2.2, Computation 4.7 of metrics. [RFC7810] for Measurement Method.

   Units of Measurement:

      See definition

      The unit of the general Bandwidth. measurement is byte per seconds.

   Measurement Point(s) with Potential Measurement Domain:

      See section 2.1, Data sources.

   Measurement Timing:

      Link Utilized bandwidth is Unidirectional utilization bandwidth
      measured between two directly connected IS-IS neighbors or OSPF
      neighbor, See section 2.1, second paragraph 5 of [RFC7810] for Measurement Timing.

   Use and Applications:

      See section 3 for use and application.

  Example 10: utilbw value on source-destination endpoint pairs

  POST /endpointcost/lookup HTTP/1.1
  Host: alto.example.com
  Content-Length: TBA
  Content-Type: application/alto-endpointcostparams+json
  Accept: application/alto-endpointcost+json,application/alto-error+json

   {
    "cost-type": {"cost-mode" : "numerical",
    "cost-metric" :  "utilbw"},
    "endpoints":  {
         "srcs" : [ "ipv4 : 192.0.2.2" ],
         "dsts" : [
           "ipv4:192.0.2.89",
           "ipv4:198.51.100.34",
           "ipv6:2000::1:2345:6789:abcd"
        ]
      }
   }

  HTTP/1.1 200 OK
  Content-Length: TBA
  Content-Type: application/alto-endpointcost+json
   {
    "meta": {
           "cost type": {
           "cost-mode": "numerical",
           "cost-metric": "utilbw"
          }
    },
  "endpoint-cost-map": {
             "ipv4:192.0.2.2" {
             "ipv4:192.0.2.89" :   0,
             "ipv4:198.51.100.34" : 2000,
             "ipv6:2000::1:2345:6789:abcd" :  5000,
                            }
           }
  }

14.

9.  Security Considerations

   The properties defined in this document present no security
   considerations beyond those in Section 15 of the base ALTO
   specification [ALTO].

   However concerns addressed in Sections "15.1 Authenticity and
   Integrity of ALTO Information", "15.2 Potential Undesirable Guidance
   from Authenticated ALTO Information" and "15.3 Confidentiality of
   ALTO Information" remain of utmost importance.  Indeed, TE
   performance is a highly sensitive ISP information and sharing TE
   metric values in numerical mode requires full mutual confidence
   between the entities managing the ALTO Server and Client.  Numerical
   TE performance information will most likely be distributed by ALTO
   Servers to Clients under strict and formal mutual trust agreements.
   One
   On the other hand, ALTO Clients must be cognizant on the risks
   attached to such information that they would have acquired outside
   formal conditions of mutual trust.

15.

10.  IANA Considerations

   IANA has added the following entries to created and now maintains the ALTO cost map Properties
   registry, defined "ALTO Cost Metric Registry",
   listed in Section 14.2, Table 3 of [RFCXXX].

      +-----------+--------------+------------------------+
      | Namespace [RFC7285].  This registry is
   located at <http://www.iana.org/assignments/alto-protocol/alto-
   protocol.xhtml#cost-metrics>.  This document requests to add the
   following entries to "ALTO Cost Meric Registry".

+----------+--------------+---------------------------------------------+
|Namespace | Property     | Reference                                   |
      +-----------+--------------+------------------------+
+----------+--------------+---------------------------------------------+
|          |  owdelay     | [RFCxxxx], [thisdraft] Section 3   |
      |           |   pdv        | [RFCxxxx], 3,[RFC2679] Section 4 3.6  |
|          | pktloss   rtt        | [RFCxxxx], [thisdraft] Section 5 4,[RFC2681],Section 2.6  |
|          | hopcount   pdv        | [RFCxxxx], [thisdraft] Section 6 5,[RFC3393],Section 2.6  |
|          | bandwidth hopcount     | [RFCxxxx], [thisdraft] Section 7 6,[RFC7285]              |
|          | maxbw pktloss      | [RFCxxxx], [thisdraft] Section 8 7,[RFC7680],Section 2.6  |
|          | maxresbw     | [RFCxxxx]  Section 9   |
      |           |  rtt         | [RFCxxxx], [thisdraft] Section 10  | 8.1,[RFC5305],Section 3.5|
|          | residbw      | [RFCxxxx], [thisdraft] Section 11  | 8.2,[RFC7810],Section 4.5|
|          | availbw      | [RFCxxxx], [thisdraft] Section 12  | 8.3,[RFC7810],Section 4.6|
|          | utilbw       | [RFCxxxx], [thisdraft] Section 13 8.4,[RFC7810,Section4.7] |
      +-----------+--------------+------------------------+

16.
+----------+--------------+---------------------------------------------+

11.  References

16.1.

11.1.  Normative References

   [I-D.ietf-idr-te-pm-bgp]
              Previdi, S., Wu, Q., Gredler, H., Ray, S.,
              jefftant@gmail.com, j., Filsfils, C., and L. Ginsberg,
              "BGP-LS Advertisement of IGP Traffic Engineering
              Performance Metric Extensions", draft-ietf-idr-te-pm-
              bgp-03
              bgp-04 (work in progress), May October 2016.

   [I-D.ietf-ippm-initial-registry]
              Morton, A., Bagnulo, M., Eardley, P., and K. D'Souza,
              "Initial Performance Metric Registry Entries", draft-ietf-
              ippm-initial-registry-01
              ippm-initial-registry-02 (work in progress), July October 2016.

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

   [RFC2679]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Delay Metric for IPPM", RFC 2679, DOI 10.17487/RFC2679,
              September 1999, <http://www.rfc-editor.org/info/rfc2679>.

   [RFC2681]  Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip
              Delay Metric for IPPM", RFC 2681, DOI 10.17487/RFC2681,
              September 1999, <http://www.rfc-editor.org/info/rfc2681>.

   [RFC3393]  Demichelis, C. and P. Chimento, "IP Packet Delay Variation
              Metric for IP Performance Metrics (IPPM)", RFC 3393,
              DOI 10.17487/RFC3393, November 2002,
              <http://www.rfc-editor.org/info/rfc3393>.

   [RFC4627]  Crockford, D., "The application/json Media Type for
              JavaScript Object Notation (JSON)", RFC 4627,
              DOI 10.17487/RFC4627, July 2006,
              <http://www.rfc-editor.org/info/rfc4627>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <http://www.rfc-editor.org/info/rfc5234>.

   [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
              Engineering", RFC 5305, DOI 10.17487/RFC5305, October
              2008, <http://www.rfc-editor.org/info/rfc5305>.

   [RFC7285]  Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
              Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
              "Application-Layer Traffic Optimization (ALTO) Protocol",
              RFC 7285, DOI 10.17487/RFC7285, September 2014,
              <http://www.rfc-editor.org/info/rfc7285>.

   [RFC7471]  Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
              Previdi, "OSPF Traffic Engineering (TE) Metric
              Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
              <http://www.rfc-editor.org/info/rfc7471>.

   [RFC7680]  Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton,
              Ed., "A One-Way Loss Metric for IP Performance Metrics
              (IPPM)", STD 82, RFC 7680, DOI 10.17487/RFC7680, January
              2016, <http://www.rfc-editor.org/info/rfc7680>.

   [RFC7752]  Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
              S. Ray, "North-Bound Distribution of Link-State and
              Traffic Engineering (TE) Information Using BGP", RFC 7752,
              DOI 10.17487/RFC7752, March 2016,
              <http://www.rfc-editor.org/info/rfc7752>.

   [RFC7810]  Previdi, S., Ed., Giacalone, S., Ward, D., Drake, J., and
              Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions",
              RFC 7810, DOI 10.17487/RFC7810, May 2016,
              <http://www.rfc-editor.org/info/rfc7810>.

16.2.

11.2.  Informative References

   [I-D.ietf-alto-deployments]
              Stiemerling, M., Kiesel, S., Scharf, M., Seidel, H., and
              S. Previdi, "ALTO Deployment Considerations", draft-ietf-
              alto-deployments-16 (work in progress), July 2016.

   [RFC6390]  Clark, A. and B. Claise, "Framework for Performance Metric
              Development", RFC 6390, July 2011.

Authors' Addresses

   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: bill.wu@huawei.com

   Y. Richard Yang
   Yale University
   51 Prospect St
   New Haven, CT  06520
   USA

   Email: yry@cs.yale.edu

   Young Lee
   Huawei
   1700 Alma Drive, Suite 500
   Plano, TX  75075
   USA

   Email: leeyoung@huawei.com
   Dhruv Dhody
   Huawei
   Leela Palace
   Bangalore, Karnataka  560008
   INDIA

   Email: dhruv.ietf@gmail.com

   Sabine Randriamasy
   Nokia Bell Labs
   Route de Villejust
   Nozay  91460
   FRANCE

   Email: sabine.randriamasy@nokia-bell-labs.com