[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: 00 01 02 03 04 05 06 draft-ietf-alto-cost-calendar

Network Working Group                                     S. Randriamasy
Internet-Draft                                           Nokia Bell Labs
Intended status: Standards Track                                 R. Yang
Expires: January 9, 2017                                 Yale University
                                                                   Q. Wu
                                                                  Huawei
                                                                 L. Deng
                                                            China Mobile
                                                               N. Schwan
                                                      Thales Deutschland
                                                           July 08, 2016


                           ALTO Cost Calendar
                draft-randriamasy-alto-cost-calendar-06

Abstract

   The goal of Application-Layer Traffic Optimization (ALTO) is to
   bridge the gap between network and applications by provisioning
   network related information in order to allow applications to make
   network informed decisions.  The present draft extends the ALTO cost
   information so as to broaden the decision possibilities of
   applications to not only decide 'where' to connect to, but also
   'when'.  This is useful to applications that need to schedule their
   data transfers and connections and have a degree of freedom to do so.
   ALTO guidance to schedule application traffic can also efficiently
   help for load balancing and resources efficiency.  Besides, the ALTO
   Cost Calendar allows to schedule the ALTO requests themselves and
   thus to save a number of ALTO transactions.

   This draft proposes new capabilities and attributes on filtered cost
   maps and endpoint costs enabling an ALTO Server to provide "Cost
   Calendars".  These capabilities are applicable to time-sensitive ALTO
   metrics.  With ALTO Cost Calendars, an ALTO Server exposes ALTO Cost
   Values in JSON arrays where each value corresponds to a given time
   interval.  The time intervals as well as other Calendar attributes
   are specified in the IRD and ALTO Server responses.

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].







Randriamasy, et al.      Expires January 9, 2017                [Page 1]


Internet-Draft             ALTO Cost Calendar                  July 2016


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 January 9, 2017.

Copyright Notice

   Copyright (c) 2016 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.  Overview of ALTO Cost Calendars . . . . . . . . . . . . . . .   5
     2.1.  ALTO Cost Calendar information features . . . . . . . . .   5
     2.2.  ALTO Calendar design characteristics  . . . . . . . . . .   6
       2.2.1.  ALTO Cost Calendar for all cost modes . . . . . . . .   7
       2.2.2.  Compatibility with legacy ALTO Clients  . . . . . . .   7
   3.  ALTO Calendar specification: IRD extensions . . . . . . . . .   7
     3.1.  Calendar attributes in the IRD resources capabilities . .   8
     3.2.  Calendars in a delegate IRD . . . . . . . . . . . . . . .   9
     3.3.  Example IRD with  ALTO Cost Calendars . . . . . . . . . .   9
   4.  ALTO Calendar specification: Service Information Resources  .  12
     4.1.  Calendar extensions for Filtered Cost Maps  . . . . . . .  13
       4.1.1.  Calendar extensions in Filtered cost map requests . .  13
       4.1.2.  Calendar extensions in Filtered Cost map responses  .  14



Randriamasy, et al.      Expires January 9, 2017                [Page 2]


Internet-Draft             ALTO Cost Calendar                  July 2016


       4.1.3.  Example transaction for a FCM with a bandwidth
               Calendar  . . . . . . . . . . . . . . . . . . . . . .  15
     4.2.  Calendar extensions in the Endpoint Cost Map Service  . .  17
       4.2.1.  Calendar specific input in  Endpoint cost  map
               requests  . . . . . . . . . . . . . . . . . . . . . .  17
       4.2.2.  Calendar attributes in the Endpoint Cost Map response  17
       4.2.3.  Example transaction for the ECS with a routingcost
               Calendar  . . . . . . . . . . . . . . . . . . . . . .  18
       4.2.4.  Example transaction for the ECS with a calendar for
               both routingcost and latency  . . . . . . . . . . . .  21
     4.3.  Recap of rules related to ALTO Cost Calendars . . . . . .  23
   5.  Use cases for ALTO Cost Schedule  . . . . . . . . . . . . . .  23
     5.1.  Bulk Data Transfer scheduling upon bandwidth calendars  .  23
       5.1.1.  Applicable example transaction  . . . . . . . . . . .  24
     5.2.  Applications with limited connectivity or access to
           datacenters . . . . . . . . . . . . . . . . . . . . . . .  25
       5.2.1.  Applicable example transaction  . . . . . . . . . . .  26
     5.3.  SDN Controller guided traffic scheduling with Calendars .  26
       5.3.1.  Applicable example transaction  . . . . . . . . . . .  27
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  27
     6.1.  Information for IANA on proposed Cost Types . . . . . . .  27
     6.2.  Information for IANA on proposed Endpoint Propeeries  . .  27
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  27
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  27
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  27
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  28
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  28

1.  Introduction

   IETF is currently standardizing the ALTO protocol which aims at
   providing guidance to overlay applications needing to select one or
   several hosts from a set of candidates able to provide a desired
   resource.  This guidance is based on parameters that affect
   performance and efficiency of the data transmission between the hosts
   such as the topological distance.  The goal of ALTO is to improve the
   Quality of Experience (QoE) in the application while optimizing
   resource usage in the underlying network infrastructure.

   The ALTO protocol in [RFC7285] specifies a Network Map which defines
   groupings of endpoints in provider-defined network regions (called
   PIDs).  The Cost Map Service, Endpoint Cost Service (ECS) and
   Endpoint Ranking Service then provide ISP-defined costs and rankings
   for connections among the specified endpoints and PIDs and thus
   incentives for application clients to connect to ISP preferred
   locations, e.g. to reduce their costs.  ALTO intentionally avoids
   provisioning realtime information as explained in the ALTO Problem
   Statement [RFC5693] and ALTO Requirements [RFC5693].Thus the current



Randriamasy, et al.      Expires January 9, 2017                [Page 3]


Internet-Draft             ALTO Cost Calendar                  July 2016


   Cost Map and Endpoint Cost Service are providing, for a given Cost
   Type, exactly one path cost value.  Applications have to query one of
   these two services to retrieve the currently valid cost values.  They
   therefore need to plan their ALTO information requests according to
   their own estimation of the frequency of cost value change.

   With [RFC7285], an ALTO client should interpret the returned costs as
   those at the query moment.  However, Network costs can fluctuate,
   e.g. due to diurnal patterns of traffic demand or planned events such
   as network maintenance, holidays or highly publicized events.
   Providing network costs for only the current time thus may not be
   sufficient, in particular for applications that can schedule their
   traffic in a span of time, for example by deferring backup to night
   during traffic trough.

   In case the ALTO Cost value changes are predicable over a certain
   period of time and the application does not require immediate data
   transfer, it can save time to get the whole set of cost values over
   this period in one ALTO response.  Using them to schedule data
   transfers would allow to optimise the network resources usage and
   QoE.  ALTO Clients and Servers can also minimize their workload by an
   appropriate scheduling of their data exchanges.

   This document extends RFC7285 to allow an ALTO server to provide
   network costs for a given duration of time.  A sequence of network
   costs across a time span for a given pair of network locations is
   named an "ALTO Cost Calendar".  The Filtered Cost Map Service and
   Endpoint Cost Service are extended to provide Cost Calendars.  In
   addition to this functional ALTO enhancement, we expect to further
   gain on storage and on the wire data exchange by gathering multiple
   Cost Values for one Cost Type into one single ALTO Server response.

   In this draft an "ALTO Cost Calendar" is specified by information
   resources capabilities that are applicable to time-sensitive ALTO
   metrics.  An ALTO Cost Calendar exposes ALTO Cost Values in JSON
   arrays where each value corresponds to a given time interval.  The
   time intervals as well as other Calendar attributes are specified in
   the IRD and in the Server response to allow the ALTO Client to
   interpret the received ALTO values.  Last, the proposed extensions
   for ALTO Calendars are applicable to any Cost Mode and they ensure
   backwards compatibility with legacy ALTO clients.

   In the rest of this document, Section 2 provides the design
   characteristics.  Sections 3 and 4 define the formal specification
   for the IRD and the information resources.  Section 5 provides non-
   normative use cases to illustrate the usage of cost calendars.  IANA
   considerations and security considerations will be completed in
   further versions.



Randriamasy, et al.      Expires January 9, 2017                [Page 4]


Internet-Draft             ALTO Cost Calendar                  July 2016


2.  Overview of ALTO Cost Calendars

   An ALTO Cost calendar provided by the ALTO Server provides 2
   information items:

   o  an array of values for a given metric, where each value
      corresponds to a time interval, wher the value array can sometimes
      be a cyclic pattern that repeats a certain number of times.

   o  attributes describing the time scope of the calendar, allowing an
      ALTO Client to properly interpret the values, such as the size and
      number of the intervals and the date of the starting point of the
      calendar.

   An ALTO Cost Calendar can be used like a "time table" to figure out
   the best time to schedule data transfers and also to proactively
   manage appllication traffic given predictable events such as flash
   crowds, traffic intensive holidays and network maintenance.  An ALTO
   Cost Calendar may be viewed as a synthetic abstraction of real
   measurements that can be historic or be a prediction for upcoming
   time periods.

   Most likely, the ALTO Cost Calendar would be used for the Endpoint
   Cost Service, assuming that a limited set of feasible Endpoints for a
   non-real time application is already identified, that they do not
   need to be accessed immediately and that their access can be
   scheduled within a given time period.  The Filtered Cost Map service
   is also applicable as long as the size of the Map allows it.

2.1.  ALTO Cost Calendar information features

   The Calendar attributes are provided in the IRD and in ALTO Server
   responses.  The IRD announces attributes with dateless values in its
   information resources capabilities, where as attributes with time
   dependent values are provided in the "meta" of Server responses.  The
   ALTO Cost Calendar attributes provide the following information:

   o  attributes to interpret the time scope of the Calendar value
      array:

      *  generic time zone,

      *  applicable time interval for each calendar value: combining
         numbers and time units to reflect for example: 1 hour, 2
         minutes, 10 seconds, 1 week, 1 month,

      *  duration of the Calendar: e.g. the number of intervals provided
         in the calendar.



Randriamasy, et al.      Expires January 9, 2017                [Page 5]


Internet-Draft             ALTO Cost Calendar                  July 2016


   o  "calendar-start-date": specifying when the calendar starts, that
      is to which date the first value of the cost calendar is
      applicable.

   o  "repeated": an optional attribute indicating how many iterations
      the provided calendar will have the same values, that the server
      may use to allow the client to schedule its next request and thus
      save its own workload by avoiding to process useless requests.

2.2.  ALTO Calendar design characteristics

   This draft introduces new capabilities and attributes that specify an
   ALTO Cost Calendar.  The protocol extension placeholders are: the
   IRD, the ALTO requests and responses for Cost calendars.

   Extensions are designed to be light and ensure backwards
   compatibility with base protocol ALTO Clients and with other
   extensions.  It uses section 8.3.7 "Parsing of Unknown Fields" of
   RFC7285 that writes: "Extensions may include additional fields within
   JSON objects defined in this document.  ALTO implementations MUST
   ignore unknown fields when processing ALTO messages."

   The calendar specific capabilities are integrated in the information
   resources of the IRD and in the "meta" member of ALTO responses to
   Cost Calendars requests.  A calendar and its capabilities are
   associated to a given information resource and within this
   information resource to a given cost type.  This design has several
   advantages:

   o  it does not introduce a new mode,

   o  it does not introduce new media types,

   o  it allows an ALTO Server to offer calendar capabilities on a cost
      type, with attributes values adapted to each information resource.

   The Applicable Calendared information resources are:

   o  the Filtered Cost Map,

   o  the Endpoint Cost Map.

   The ALTO Server can choose in which frequency it provides cost
   Calendars to ALTO Clients.  It may either provide calendar updates
   starting at the request date, or carefully schedule its updates so as
   to take profit from a potential repetition/periodicity of calendar
   values.




Randriamasy, et al.      Expires January 9, 2017                [Page 6]


Internet-Draft             ALTO Cost Calendar                  July 2016


2.2.1.  ALTO Cost Calendar for all cost modes

   Calendars are well-suited for values encoded in the 'numerical' mode.
   However, Calendars can also represent any metric considered as time-
   sensitive by an ALTO Server.  For example, types of Cost values such
   as JSONBool can also be expressed as calendars, as states may be
   "true" or "false" depending on given time periods or likewise, values
   represented by strings, such as "medium", "high", "low", "blue",
   "open" .

   Note also that a Calendar is applicable as well to time-sensitive
   metrics provided in the 'ordinal' mode, if these values are time-
   sentitive and their update is carefully managed by the ALTO Server.

2.2.2.  Compatibility with legacy ALTO Clients

   The ALTO protocol extensions for Cost Calendars have been defined so
   as to ensure that Calendar capable ALTO Servers can provide legacy
   ALTO Clients with legacy information resources as well.  That is a
   legacy ALTO Client can request resources and receive responses as
   specified in RFC7285.

   For compatibility with legacy ALTO Clients specified in RFC7285,
   calendared information resources are not applicable for Cost Maps for
   the following reason: a legacy ALTO client would receive a Calendared
   Cost Map via an HTTP 'GET' command.  As specified in section 8.3.7 of
   RFC7285, it will ignore the Calendar Attributes indicated in the
   "meta" of the responses.  Therefore, lacking information on calendar
   attributes, it will not be able to correctly interpret and process
   the values of the received array of calendar cost values.

3.  ALTO Calendar specification: IRD extensions

   The Calendar attributes in the IRD information resources capabilities
   carry constant dateless values.  A calendars is associated to an
   information resource rather than a cost type.  For example, a Server
   can provide a "routingcost" values calendar for the Filtered Cost Map
   Service at a granularity of one day and a "routingcost" values
   calendar for the Endpoint Cost service at a finer granularity but for
   a limited number of endpoints.

   NOTE : to cope with existing representation fomats and proposed
   unified ALTO naming schemes proposed in the WG, the names given in
   the current proposal may be revised in further versions.







Randriamasy, et al.      Expires January 9, 2017                [Page 7]


Internet-Draft             ALTO Cost Calendar                  July 2016


3.1.  Calendar attributes in the IRD resources capabilities

   When for an applicable resource , an ALTO Server provides a Cost
   Calendar for a given Cost Type, it MUST indicate this in the IRD
   capabilities of this resource, by an object of type
   'CalendarAttributes', associated to this Cost Type and specified
   below.

   The capabilities of a Calendar aware information resource entry have
   a member named "calendar-attributes" which is an array of objects of
   type CalendarAttributes.  The array has as many values as cost-type-
   names announced for the resource.  It is necessary to use an array
   because of resources such as Filtered Cost Map and Endpoint Cost Map,
   for which the member "cost-type-names" is an array of 1 or more
   values.  If for a given cost-type-name of this ressource no Calendar
   attributes are defined, the ALTO Server MUST replace that value in
   the array by the symbol 'null'.

   RULE: a member "calendar-attributes" MUST appear only once for each
   applicable cost type name of a resource entry.  If "calendar-
   attributes" are specified several times for a same "cost-type-name"
   in the capabilities of a resource entry, the ALTO client SHOULD
   ignore any calendar capabilities on this "cost-type-name" for this
   entry.

   CalendarAttributes calendar-attributes <1..*>;

   object{
     [JSONString   cost-type-name;]
     JSONString    time-interval-size;
     JSONNumber    number-of-intervals;
   } CalendarAttributes;

   o  "cost-type-name":

      *  an optional member indicating the cost-type-name in the IRD
         entry to which the capabilities apply.  If this not present, it
         MUST be assumed to correspond to its index in the "cost-type-
         names" list of the IRD resource entry.

   o  "time-interval-size":

      *  is the duration of an ALTO calendar time interval, expressed as
         a time unit appended to the number of these units.  The time
         unit, ranges from "second" to "year".  The number is encoded
         with an integer.  Example values are: "5 minute" , "2 hour",
         meaning that each calendar value applies on a time interval
         that lasts respectively 5 minutes and 2 hours.



Randriamasy, et al.      Expires January 9, 2017                [Page 8]


Internet-Draft             ALTO Cost Calendar                  July 2016


   o  "number-of-intervals":

      *  the integer number of values of the cost calendar array, at
         least equal to 1.

   - Attribute "cost-type-name" , if used, provides a better readability
   to the calendar attributes specified in the IRD and avoids confusion
   with calendar attributes of other cost-types.

   - Multiplying Attributes 'time-interval-size' and 'number-of-
   intervals' provides the duration of the provided calendar.  For
   example an ALTO Server may provide a calendar for ALTO values
   changing every 'time-interval-size' equal to 5 minutes.  If 'number-
   of-intervals' has the value 12, then the duration of the provided
   calendar is "1 hour".

3.2.  Calendars in a delegate IRD

   One option to clarify IRD resources is that a "root" ALTO Server
   implementing base protocol resources delegates "specialized"
   information resources such as the ones providing Cost Calendars to
   another ALTO Server running in a subdomain specified with its URI in
   the "root" ALTO Server.  This option is described in Section 9.2.4
   "Delegation using IRDs" of RFC7285.

   This document provides an example, where a "root" ALTO Server runs in
   a domain called "alto.example.com".  It delegates the announcement of
   Calendars capabilities to an ALTO Server running in a subdomain
   called "custom.alto.example.com".  The location of the "delegate
   Calendar IRD" is assumed to be indicated in the "root" IRD by the
   resource entry: "custom-calendared-resources".

   Another advantage is that some Cost Types for some resources may be
   more advantageous as Cost Calendars and it makes few sense to get
   them as a single value.  For example, Cost Types with predictable and
   frequently changing values, calendared in short time intervals such
   as a minute.

3.3.  Example IRD with ALTO Cost Calendars

   The cost types in this example are either specified in the base ALTO
   protocol or may be proposed in other drafts see
   [draft-wu-alto-te-metrics].  In this example the available cost
   metrics are indicated in the "meta" field by cost type names "num-
   routingcost", "num-latency", "num-pathbandwidth" and "string-quality-
   status".  Metrics "routingcost" , 'latency' and 'Availbandwidth' are
   available in the "numerical" Cost Mode.  Metric "quality-status" is
   available in the "string" Cost Mode.



Randriamasy, et al.      Expires January 9, 2017                [Page 9]


Internet-Draft             ALTO Cost Calendar                  July 2016


   This ALTO server does not provide a calendar for cost type name num-
   AShopcount.

   The example IRD includes 2 particular URIs providing calendars:

   o  "http://custom.alto.example.com/calendar/costmap/filtered": a
      filtered cost map in which calendar capabilities are indicated for
      cost type names: "num-routingcost", "num-pathbandwidth" and
      "string-service-status",

   o  "http://custom.alto.example.com/endpointcost/calendar/lookup": an
      endpoint cost map in which in which calendar capabilities are
      indicated for cost type names: "num-routingcost", "num-TEpktloss",
      "num-pathbandwidth", "string-service-status".

   The design of the Calendar capabilities allows that some calendars on
   a cost type name are available in several information resources with
   different Calendar Attributes.  This is the case for calendars on
   "num-routingcost", "num-pathbandwidth" and "string-service-status" ,
   available in both the Filtered Cost map and Endpoint Cost map
   service, but with different time interval sizes for "num-
   pathbandwidth" and "string-service-status".

GET /calendars-directory HTTP/1.1
Host: custom.alto.example.com
Accept: application/alto-directory+json,application/alto-error+json
---------------

HTTP/1.1 200 OK
Content-Length: [TODO]
Content-Type: application/alto-directory+json

   {
     "meta" : {
        "cost-types": {
           "num-routingcost": {
              "cost-mode" : "numerical",
              "cost-metric" : "routingcost"
           },
           "num-latency": {
              "cost-mode"  : "numerical",
              "cost-metric": "latency"
           },
           "num-pathbandwidth": {
              "cost-mode"  : "numerical",
              "cost-metric": "Availbandwidth",
           },
           "string-qual-status": {



Randriamasy, et al.      Expires January 9, 2017               [Page 10]


Internet-Draft             ALTO Cost Calendar                  July 2016


              "cost-mode"  : "string",
              "cost-metric": "quality-status",
           }
         ... other meta ...
       },

    "resources" : {
       "filtered-cost-map-calendar" : {
           "uri" : "http://custom.alto.example.com/calendar/costmap/filtered",
           "media-type" : "application/alto-costmap+json",
           "accepts" : "application/alto-costmapfilter+json",
           "capabilities" : {
              "cost-constraints" : true,
              "cost-type-names"  : [ "num-routingcost", "num-pathbandwidth",
                                     "string-service-status" ],
              "calendar-attributes" : [
                 {"cost-type-names" : [ "num-routingcost", "num-pathbandwidth" ],
                  "time-interval-size" : "1 hour",
                  "number-of-intervals" : 24
                 },
                 {"cost-type-names" : "string-service-status",
                  "time-interval-size" : "30 minute",
                  "number-of-intervals" : 48
                 }
               ] // end calendar-attributes
              "uses": [ "my-default-network-map" ]
              }
           },

       "endpoint-cost-calendar-map" : {
         "uri" : "http://custom.alto.example.com/calendar/endpointcost/calendar/lookup",
         "media-types" : [ "application/alto-endpointcost+json" ],
         "accepts" : [ "application/alto-endpointcostparams+json" ],
         "capabilities" : {
           "cost-constraints" : true,
           "cost-type-names" : [ "num-routingcost", "num-latency",
                                 "num-pathbandwidth", "string-service-status" ],
           "calendar-attributes" : [
              {"cost-type-names" : "num-routingcost",
               "time-interval-size" : "1 hour",
               "number-of-intervals" : 24
              },
              {"cost-type-names" : "latency",
               "time-interval-size" : "5 minute",
               "number-of-intervals" : 12
              },
              {"cost-type-names" : "num-pathbandwidth",
               "time-interval-size" : "1 minute",



Randriamasy, et al.      Expires January 9, 2017               [Page 11]


Internet-Draft             ALTO Cost Calendar                  July 2016


               "number-of-intervals" : 60
              },
              {"cost-type-names" : "string-service-status",
               "time-interval-size" : "2 minute",
               "number-of-intervals" : 30
              },
             ]
           "uses": [ "my-default-network-map" ]
         } // ECM capab
      } //info resource N
   } // ressources


   In this example IRD, for the filtered cost map service, all calendars
   have a duration of 1 day and start in the "request-date" mode, that
   is the "date" of first value of the array belongs to the time
   interval "containing" the date of the request.

   o  the Calendar for 'num-routingcost': is an array of 24 values each
      provided on a time interval lasting 1 hour.

   o  the Calendar for 'num-pathbandwidth': is an array of 24 values
      each provided on a time interval lasting 1 hour.

   o  the Calendar for "string-service-status": "is an array of 48
      values each provided on a time interval lasting 30 minutes.

   For the endpoint cost map service, the cost calendars have a duration
   of 1 day for "num-routingcost" and 1 hour for the 3 other cost type
   names.

   o  the Calendar for 'num-routingcost': is an array of 24 values each
      provided on a time interval lasting 1 hour.

   o  the Calendar for 'latency'': is an array of 12 values each
      provided on a time interval lasting 5 minutes.

   o  the Calendar for 'num-pathbandwidth': is an array of 60 values
      each provided on a time interval lasting 1 minute.

   o  the Calendar for "string-service-status": "is an array of 30
      values each provided on a time interval lasting 2 minutes.

4.  ALTO Calendar specification: Service Information Resources

   This section documents the individual information resources defined
   to provide the Calendared information services defined in this
   document.



Randriamasy, et al.      Expires January 9, 2017               [Page 12]


Internet-Draft             ALTO Cost Calendar                  July 2016


   The reference time zone for the provided time values is GMT because
   the option chosen to express the time format is the HTTP header
   fields format:

                    Date: Tue, 15 Nov 1994 08:12:31 GMT


4.1.  Calendar extensions for Filtered Cost Maps

   A legacy ALTO client requests and gets filtered cost map responses as
   specified in RFC7285.

4.1.1.  Calendar extensions in Filtered cost map requests

   The input parameters of a "legacy" request for a filtered cost map,
   defined by object ReqFilteredCostMap in section 11.3.2 of RFC7285,
   are augmented with one additional member.

   A Calendar-aware ALTO client requesting a Calendar on a given Cost
   Type for a Filtered Cost Map resource having Calendar capabilities
   MUST add the following field to its input parameters:

   JSONBoolean    calendared<1..*>;

   This field is an array of 1 to N boolean values, where N is the
   number of requested metrics.  Each boolean value indicates whether or
   not the ALTO Server should provide the values for this Cost Type as a
   calendar.

   This field MUST NOT be specified if member "calendar-attributes" is
   not present or has the value 'false' for this information resource.

   A Calendar-aware ALTO client supporting single cost type values, as
   specified in RFC7285, MUST provide an array of 1 element:
   "calendared" : [true],

   A Calendar-aware ALTO client that is also Multi-Cost aware MUST
   provide an array of N values set to "true" or "false", depending
   whether it wants the applicable Cost Type values as a single or
   calendared value.

   If this field is not present, it MUST be assumed to have only values
   equal to "false".








Randriamasy, et al.      Expires January 9, 2017               [Page 13]


Internet-Draft             ALTO Cost Calendar                  July 2016


4.1.2.  Calendar extensions in Filtered Cost map responses

   The calendared costs are JSONArrays instead of JSONNumbers for the
   legacy ALTO implementation.  All arrays have a number of values equal
   to 'number-of-intervals'.

   The "meta" field of a Calendared Filtered Cost map response MUST
   include at least:

   o  if the ALTO Client supports cost values for one Cost Type at a
      time only: the "meta" fields specified specified in RFC 7285 for
      these information service responses:

      *  "dependent-vtags ",

      *  "cost-type" field.

   o  if the ALTO Client supports cost values for several Cost Types at
      a time, as specified in [draft-ietf-alto-multi-cost] : the "meta"
      fields specified in [draft-ietf-alto-multi-cost] for these
      information service responses:

      *  "dependent-vtags ",

      *  "multi-cost-types" field.

   In addition, the "meta" field of a Calendared Filtered Cost map
   response MUST include the member "calendar-response-attributes" for
   the requested information resource, together with the values provided
   by the ALTO Server for these attributes.  This member is an array of
   objects of type "CalendarResponseAttributes", defined as follows:

   CalendarResponseAttributes calendar-response-attributes <1..*>;

   object{
     JSONString    calendar-start-time;
     JSONString    time-interval-size;
     JSONNumber    number-of-intervals;
     [JSONNumber   repeated;]            [OPTIONAL]
   } CalendarResponseAttributes;

   o  "calendar-start-time": indicates the date at which the first value
      of the calendar applies.  By default, the value provided for the
      "calendar-start-time" attribute SHOULD be no later than the
      request date.

   o  "time-interval-size": as specified in section "Calendar attributes
      in the IRD resources capabilities",



Randriamasy, et al.      Expires January 9, 2017               [Page 14]


Internet-Draft             ALTO Cost Calendar                  July 2016


   o  "number-of-intervals": as specified in section "Calendar
      attributes in the IRD resources capabilities",

   o  "repeated": is an optional field provided for Calendars.  It is an
      integer N greater or equal to '1' that indicates how many
      iterations of the calendar value array starting at the date
      indicated by "calendar-start-time" have the same values.  The
      number N includes the provided iteration.

   Using the member "repeated" helps minimizing on the wire data
   exchange: by providing it, an ALTO Server will avoid unecessary
   processing of requests for Calendars with unchanged values while it
   allows ALTO Clients to save their resources as well.

   For example: if the "calendar-start-time" member has value "Mon, 30
   Jun 2014 at 00:00:00 GMT" and if the value of member "repeated" is
   equal to 4, it means that the calendar values are the same values on
   Monday, Tuesday, Wednesday and Thursday.  The ALTO Client thus may
   use the same calendar for the next 4 duration periods following
   "calendar-start-time".

4.1.3.  Example transaction for a FCM with a bandwidth Calendar

   An example of non-real time information that can be provisioned in a
   'calendar' is the expected path bandwidth.  While the transmission
   rate can be measured in real time by end systems, the operator of a
   data center is in the position of formulating preferences for given
   paths, at given time periods for example to avoid traffic peaks due
   to diurnal usage patterns.  In this example, we assume that an ALTO
   Client requests a bandwidth calendar as specified in the IRD to
   shedule its bulk data transfers as described in the use cases.

   In the example IRD, calendars for cost type name "num-pathbandwidth"
   are available for the information resources: "filtered-cost-calendar-
   map" and "endpoint-cost-calendar-map".  The ALTO Client requests a
   calendar for "num-pathbandwidth" via a POST request for a filtered
   cost map.

   We suppose in this example that the ALTO Client sends its request on
   Tuesday July 1st 2014 at 13:15











Randriamasy, et al.      Expires January 9, 2017               [Page 15]


Internet-Draft             ALTO Cost Calendar                  July 2016


  POST /calendar/costmap/filtered HTTP/1.1
  Host: alto.example.com
  Content-Length: [TODO]
  Content-Type: application/alto-costmapfilter+json
  Accept: application/alto-costmap+json,application/alto-error+json

  {
    "cost-type" : {"cost-mode" : "numerical", "cost-metric" : "Availbandwidth"},
    "calendared" : [true],

    "pids" : {
       "srcs" : [ "PID1", "PID2" ],
       "dsts" : [ "PID1", "PID2", "PID3" ]
    }
  }


  HTTP/1.1 200 OK
  Content-Length: [TODO]
  Content-Type: application/alto-costmap+json

  {
    "meta" : {
      "dependent-vtags" : [...],
      "cost-type" : {"cost-mode" : "numerical", "cost-metric" : "Availbandwidth"},
      "calendar-response-attributes" : [
         "calendar-start-time" : Tue, 1 Jul 2014 13:00:00 GMT,
         "time-interval-size" : "2 hour",
         "numb-intervals" : 12
       ]
     },

    "cost-map" : {
       "PID1": { "PID1": [v1,v2, ... v12],
                 "PID2": [v1,v2, ... v12],
                 "PID3": [v1,v2, ... v12] },
       "PID2": { "PID1": [v1,v2, ... v12],
                 "PID2": [v1,v2, ... v12],
                 "PID3": [v1,v2, ... v12] }
    }
  }










Randriamasy, et al.      Expires January 9, 2017               [Page 16]


Internet-Draft             ALTO Cost Calendar                  July 2016


4.2.  Calendar extensions in the Endpoint Cost Map Service

   This document extends the Endpoint Cost Service, as defined in
   {11.5.1} of [RFC7285], by adding new input parameters and
   capabilities, and by returning JSONArrays instead of JSONNumbers as
   the cost values.  The media type (11.5.1.1} and HTTP method
   (11.5.1.2} are unchanged.

4.2.1.  Calendar specific input in Endpoint cost map requests

   The extensions to the requests for calendared Endpoint Cost Maps are
   the same as for the Filtered Cost Map Service, specified in section
   XXXX of this draft.

   The ReqEndpointCostMap object for a Calendared ECM request will have
   the following format:

   object {
     CostType       cost-type;
     [JSONBoolean    calendared<1..*>;]
     EndpointFilter endpoints;
   } ReqEndpointCostMap;

   object {
     [TypedEndpointAddr srcs<0..*>;]
     [TypedEndpointAddr dsts<0..*>;]
   } EndpointFilter;


4.2.2.  Calendar attributes in the Endpoint Cost Map response

   The "meta" field of a Calendared Endpoint Cost map response MUST
   include at least:

   o  if the ALTO Client supports cost values for one Cost Type at a
      time only: the "meta" fields specified in {11.5.1.6} of RFC 7285
      for the Endpoint Cost response:

      *  "cost-type" field.

   o  if the ALTO Client supports cost values for several Cost Types at
      a time, as specified in [draft-ietf-alto-multi-cost] : the "meta"
      fields specified in [draft-ietf-alto-multi-cost] for the the
      Endpoint Cost response:

      *  "multi-cost-types" field.





Randriamasy, et al.      Expires January 9, 2017               [Page 17]


Internet-Draft             ALTO Cost Calendar                  July 2016


   If the client request does not provide member "calendared" or if it
   provides it with a value equal to 'false', then the ALTO Server
   response is exactly as specified in the above cited references.

   If the ALTO client provides member "calendared" with a value equal to
   'true' in the input parameters, the "meta" member of a Calendared
   Endpoint Cost Map response MUST include the same addifional member
   "calendar-response-attributes" as specified for the Filtered Cost Map
   Service.  The Server response is thus changed as follows:

   o  the "meta" member has one additional field
      "CalendarResponseAttributes", as specified for the Filtered Cost
      Map Service,

   o  the calendared costs are JSONArrays instead of JSONNumbers for the
      legacy ALTO implementation.  All arrays have a number of values
      equal to 'number-of-intervals'.

4.2.3.  Example transaction for the ECS with a routingcost Calendar

   Let us assume an Application Client is located in an end sytem with
   limited resources and having an access to the network that is either
   intermittent or provides an acceptable quality in limited but
   predictable time periods.  Therefore, it needs to both schedule its
   resources greedy networking activities and its ALTO transactions.

   The Application Client has the choice to trade content or resources
   with a set of Endpoints and needs to decide with which one it will
   connect and at what time.  For instance, the Endpoints are spread in
   different time-zones, or have intermittent access.  In this example,
   the 'routingcost' is assumed to be time sentitive with values
   provided as ALTO Calendars.

   The ALTO Client associated to the Application Client queries an ALTO
   Calendar on 'routingcost' and will get the Calendar covering the 24
   hours time period "containing" the date and time of the ALTO client
   request.

   For Cost Type 'num-routingcost', the sollicited ALTO Server has
   defined 3 different daily patterns each represented by a Calendar, to
   cover the week of Monday June 30th at 00:00 to Sunday July 6th 23:59:

   - C1 for Monday, Tuesday, Wednesday, Thursday, (week days)

   - C2 for Saturday, Sunday, (week end)

   - C3 for Friday (maintenance outage on July 4, 2014 from 02:00:00 GMT
   to 04:00:00 GMT, or big holiday such as New Year evening).



Randriamasy, et al.      Expires January 9, 2017               [Page 18]


Internet-Draft             ALTO Cost Calendar                  July 2016


   In the following example, the ALTO Client sends its request on
   Tuesday July 1st 2014 at 13:15.

















































Randriamasy, et al.      Expires January 9, 2017               [Page 19]


Internet-Draft             ALTO Cost Calendar                  July 2016


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

  {
    "cost-type" : {"cost-mode" : "numerical", "cost-metric" : "routingcost"},
    "calendared" : [true],
    "endpoints" : {
      "srcs": [ "ipv4:192.0.2.2" ],
      "dsts": [
        "ipv4:192.0.2.89",
        "ipv4:198.51.100.34",
        "ipv4:203.0.113.45",
        "ipv6:2000::1:2345:6789:abcd"
      ]
    }
  }


  HTTP/1.1 200 OK
  Content-Length: [TODO]
  Content-Type: application/alto-endpointcost+json

  {
    "meta" : {
      "cost-type" : {"cost-mode" : "numerical", "cost-metric" : "routingcost"},
      "calendar-response-attributes" : [
         { "calendar-start-time" : Mon, 30 Jun 2014 00:00:00 GMT,
           "time-interval-size" : "1 hour",
           "numb-intervals" : 24,
           "repeated": 4 }
        ],
      } // end meta

      "endpoint-cost-map" : {
        "ipv4:192.0.2.2": {
          "ipv4:192.0.2.89"    : [v1, v2, ... v24],
          "ipv4:198.51.100.34" : [v1, v2, ... v24],
          "ipv4:203.0.113.45"  : [v1, v2, ... v24],
          "ipv6:2000::1:2345:6789:abcd" : [v1, v2, ... v24]
        }
      }
  }






Randriamasy, et al.      Expires January 9, 2017               [Page 20]


Internet-Draft             ALTO Cost Calendar                  July 2016


   When the Client gets the Calendar for "routingcost", it sees that the
   "calendar-start-time" is Monday at 00h00 GMT and member "repeated" is
   equal to '4'.  It understands that the provides values are valid
   until Thursday included and will only need to get a Calendar update
   on Friday.

4.2.4.  Example transaction for the ECS with a calendar for both
        routingcost and latency

   In this example, it is assumed that the ALTO Server implements multi-
   cost capabilities, as specified in [draft-ietf-alto-multi-cost] .
   That is, an ALTO client can request and receive values for several
   cost types in one single transaction.  An illustrating use case is a
   path selection done on the basis of 2 metrics: routing cost and
   latency.

   As in the previous example, the IRD indicates that the ALTO Server
   provides "routingcost" Calendars in terms of 24 time intervals of 1
   hour each.

   For metric "latency", the IRD indicates that the ALTO Server provides
   Calendars in terms of 12 time intervals values lasting each 5
   minutes.

   In the following example transaction, the ALTO Client sends its
   request on Tuesday July 1st 2014 at 13:15.

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

  {
    "multi-cost-types" : [
        {"cost-mode" : "numerical", "cost-metric" : "routingcost"},
        {"cost-mode" : "numerical", "cost-metric" : "latency"}
    ],
    "calendared" : [true, true],
    "endpoints" : {
      "srcs": [ "ipv4:192.0.2.2" ],
      "dsts": [
        "ipv4:192.0.2.89",
        "ipv4:198.51.100.34",
        "ipv4:203.0.113.45",
        "ipv6:2000::1:2345:6789:abcd"
      ]
    }



Randriamasy, et al.      Expires January 9, 2017               [Page 21]


Internet-Draft             ALTO Cost Calendar                  July 2016


  }


  HTTP/1.1 200 OK
  Content-Length: [TODO]
  Content-Type: application/alto-endpointcost+json

  {
    "meta" : {
      "multi-cost-types" : [
        {"cost-mode" : "numerical", "cost-metric" : "routingcost"},
        {"cost-mode" : "numerical", "cost-metric" : "latency"}
       ],
      "calendar-response-attributes" : [
         { "cost-type-name : num-routingcost"
           "calendar-start-time" : Mon, 30 Jun 2014 00:00:00 GMT,
           "time-interval-size" : "1 hour",
           "numb-intervals" : 24,
           "repeated": 4 },
         { "cost-type-name : num-latency"
           "calendar-start-time" : Tue, 1 Jul 2014 13:00:00 GMT,
           "time-interval-size" : "5 minute",
           "numb-intervals" : 12}
       ],
      } // end meta

      "endpoint-cost-map" : {
        "ipv4:192.0.2.2": {
          "ipv4:192.0.2.89"    : [[r1, r2, ... r24], [l1, l2, ... l12]],
          "ipv4:198.51.100.34" : [[r1, r2, ... r24], [l1, l2, ... l12]],
          "ipv4:203.0.113.45"  : [[r1, r2, ... r24], [l1, l2, ... l12]],
          "ipv6:2000::1:2345:6789:abcd" : [[r1, r2, ... r24], [l1, l2, ... l12]]
        }
      }
  }


   When receiving the response, the client sees that the calendar values
   for 'routing cost' are repeated for 4 iterations.  Therefore, in its
   next requests until the routing cost calendar is expected to change,
   the client will only need to request a calendar for "latency".

   Without the ALTO Calendar extensions, the ALTO client would have no
   clue on the dynamicity of the metric value change and would spend
   needless time requesting values at an inappropriate pace.  In
   addition, without the Multi-Cost ALTO capabilities, the ALTO client
   would duplicate this waste of time as it would need to send one
   request per cost metric.



Randriamasy, et al.      Expires January 9, 2017               [Page 22]


Internet-Draft             ALTO Cost Calendar                  July 2016


4.3.  Recap of rules related to ALTO Cost Calendars

   XXXXX TO BE COMPLETED + MOVED AT THE END OF THE SPECS

   A Calendar-aware ALTO Server MUST implement the base protocol
   specified in RFC7285.

   If no Calendar attributes are defined for a given Cost Type, in a
   given resource entry, the ALTO Server MUST set the value in the
   'calendar-attributes' array to the symbol 'null' .

   When a metric is available as a calendar, it MUST be available as a
   single value.  An ALTO Server aquiring cost values in limited time
   intervals only can construct a single value from the value array.

   Calendared information resources MUST be requested via a POST method.

   If this member "repeat-indication" is not present in the calendar
   attributes indicated in the IRD, it MUST be assumed to have a value
   equal to "false".

5.  Use cases for ALTO Cost Schedule

   [THIS SECTION NEEDS TO BE SHORTENED ]

   This section presents use cases showing the benefits of ALTO Cost
   calendars for applications needing to decide both "where" to connect
   and "when".

5.1.  Bulk Data Transfer scheduling upon bandwidth calendars

   Large Internet Content Providers (ICPs) like Facebook or YouTube, as
   well as CDNs rely on data replication across multiple sites and time
   zones to offload the core site and increase user experience through
   shorter latency from a local site.  Typically the usage pattern of
   these data centers or caches follows a location dependent diurnal
   demand pattern.  In these examples, data replication across the
   various locations of an ICP, leads to bulk data transfers between
   datacenters on a diurnal pattern.

   In the meantime, there is a degree of freedom on when the content is
   transmitted from the origin server to the caching node, or from the
   core site to a local site.  However, scheduling these data transfers
   is a non-trivial task as they should not infer with the user peak
   demand to avoid degradation of user experience and to decrease
   billing costs for the datacenter operator by leveraging off-peak
   hours for the transfer.




Randriamasy, et al.      Expires January 9, 2017               [Page 23]


Internet-Draft             ALTO Cost Calendar                  July 2016


   As a result, these ICPs need to have a good knowledge on the link
   utilization patterns between the different datacenters before making
   an efficient scheduling decision.  While usage data today is already
   gathered and used to schedule data transfers, provisioning these data
   gets increasingly complex with the number of CDN nodes and datacenter
   operators that are involved.  In particular, privacy concerns prevent
   that this kind of data is shared across administrative domains.  The
   ALTO Cost Calendar avoids these problems by presenting an abstracted
   view of time sensitive utilization maps through a dedicated ALTO
   service to allow ICPs a coherent scheduling of data transfers across
   administrative domains and time zones.

   Likewise, bandwidth Calendaring allows network operators to reserve
   resources in advance according to agreements with their customers,
   enabling them to transmit data with specified starting time and
   duration, for example, for a scheduled bulk data replication between
   data centers.  Traditionally, this can be supported by a Network
   Management System operation such as path pre-establishment and
   activation on the agreed starting time.  However, this does not
   provide efficient network usage since the established paths exclude
   the possibility of being used by other services even when they are
   not used for undertaking any service.

   An ALTO Cost calendar for TE metrics on transfer paths can support
   the scheduled bulk data replication with better efficiency since it
   can alleviate the processing burden on network elements.

   Cost calendars for these time-sensitive ALTO TE metrics need to
   consider the network topology and the dynamicity of the traffic.  For
   example, a small topology with low density and low capacity that
   carries inpredictable, heavy and bursty traffic has few chances to
   exhibit stationary TE metric value patterns over large periods and
   would benefit to use the ALTO Calendar over smaller time slots.  Some
   ALTO TE metric values, even aggregated over time may need to be
   updated at a frequency that would require doing ALTO requests at a
   pace that would be overload both the ALTO Client and the Server.
   Large high capacity topologies would benefit from Cost Calendars with
   a coarse time granularity for the filtered cost map service where as
   Calendars of finer time granularity for the Endpoint Cost Service
   would be better suited for small low density and capacity topologies.

5.1.1.  Applicable example transaction

   Assuming a Large high capacity topology, an applicable example
   transaction for this us case is provided by section 4.1.3.  "Example
   transaction for a FCM with a "request-date" bandwidth Calendar".





Randriamasy, et al.      Expires January 9, 2017               [Page 24]


Internet-Draft             ALTO Cost Calendar                  July 2016


5.2.  Applications with limited connectivity or access to datacenters

   Some applications are limited in their connectivity either in time or
   resources or both.  For example applications running on devices in
   remote locations or in developing countries that need to synchronize
   their state with a data center periodically, in particular if
   sometimes there is no connection at all.  Example applications are
   enterprise database update, remote learning, remote computation
   distributed on several data center endpoints.

   Wireless connections have a variable quality and may even be
   intermittent.  On the other hand, the wireless network conditions
   have a rapid impact on applications while they can sometimes be
   predicted over a span of time.  Non real time applications and time-
   insensitive data transfers such as client patching, archive syncing,
   etc. can benefit from careful scheduling.  It is thus desirable to
   provide ALTO clients with routing costs to connection nodes (i.e.
   Application Endpoints) over different time periods.  This would allow
   end systems using ALTO aware application clients to schedule their
   connections to application endpoints.

   Another challenge arises with applications using data and physical
   resources scattered around the world.  For non-real time
   applications, the interaction with Endpoints can be orchestratrated
   and scheduled at the time slots corresponding to the best possible
   network conditions.  For instance, resource Ra downloaded from
   Endpoint EPa at time t1, Resource Rb uploaded to EPb at time t2, some
   batch computation involving Ra and Rb done on EPc at time t3 and
   results R(A,B) downloaded to EPd and EPe at time t4.

     +-----+                                           +-----+
     | EPa |                                           | EPb | <----- Rb
     +-----+                                           +-----+   (t2=50)
        |                   +-------+                     |
        Ra -------------->  | EPc   |                     |
        (time t1=10)        |       |                     |
                            |t3=100 |  <----------------- Rb
                            +-------+
                                | \
                                |  \
                              R(Ra,Rb)
                             (t4=200)
                                |     \
                                |      -------------------.
                                V                         V
                             +-----+                   +-----+
                             | EPd |                   | EPe |
                             +-----+                   +-----+



Randriamasy, et al.      Expires January 9, 2017               [Page 25]


Internet-Draft             ALTO Cost Calendar                  July 2016


5.2.1.  Applicable example transaction

   An applicable example transaction for this use case is provided by
   section 4.2.3.  "Example transaction for the ECS with a "periodic"
   routingcost Calendar".

5.3.  SDN Controller guided traffic scheduling with Calendars

   An ALTO Server can assist an SDN Controller by hosting abstracted
   network information that can be provided to SDN aware applications
   via an ALTO Client.

   Via the Northbound interface (NBI), applications may get QoE
   impacting information such as network provider preferences w.r.t.
   delay and bandwidth on the network paths.  Such information may be
   provided via the ALTO Service.

   One key objective of an SDN controller is the ability to balance the
   application traffic whenever possible.  Resources availability may
   often be predicted and strong incentives for applications to time
   shift their traffic may be given by network operators appropriately
   setting routing cost values at different time values, according to
   their policy on network utilization over time.

   To achieve this objective, the SDN controller can:

   1.  get the network state information from its controlled network
       elements through its southbound API and derive an estimation of
       these values over given time frames

   2.  abstract the network topology and end to end path costs and store
       them in an ALTO Server as Network Maps and Cost Calendars

   3.  deliver these values to ALTO Clients linked to SDN applications,
       through the NBI.

   This way:

   o  On one hand, the applications get the best possible QoE, as they
      can pick the best time for them to access one or more Endpoints or
      PIDs,

   o  One the other hand, the SDN controller achieves load balancing and
      optimizes application traffic as it may guide the application
      traffic so as to better distribute the traffic over time.






Randriamasy, et al.      Expires January 9, 2017               [Page 26]


Internet-Draft             ALTO Cost Calendar                  July 2016


5.3.1.  Applicable example transaction

   An applicable example transaction for this use case is provided by
   section 4.2.4.  "Example transaction for the ECS with a calendar on
   both routingcost and latency".

6.  IANA Considerations

   Information for the ALTO Endpoint property registry maintained by the
   IANA and related to the new Endpoints supported by the acting ALTO
   server.  These definitions will be formulated according to the syntax
   defined in Section on "ALTO Endpoint Property Registry" of [RFC7285]
   ,

   Information for the ALTO Cost Type Registry maintained by the IANA
   and related to the new Cost Types supported by the acting ALTO
   server.  These definitions will be formulated according to the syntax
   defined in Section on "ALTO Cost Type Registry" of [RFC7285],

6.1.  Information for IANA on proposed Cost Types

   When a new ALTO Cost Type is defined, accepted by the ALTO working
   group and requests for IANA registration MUST include the following
   information, detailed in Section 11.2: Identifier, Intended
   Semantics, Security Considerations.

6.2.  Information for IANA on proposed Endpoint Propeeries

   Likewise, an ALTO Endpoint Property Registry could serve the same
   purposes as the ALTO Cost Type registry.  Application to IANA
   registration for Endpoint Properties would follow a similar process.

7.  Acknowledgements

   Thank you to Diego Lopez, He Peng and Haibin Song and the ALTO WG for
   fruitful discussions.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.






Randriamasy, et al.      Expires January 9, 2017               [Page 27]


Internet-Draft             ALTO Cost Calendar                  July 2016


   [RFC5693]  Seedorf, J. and E. Burger, "Application-Layer Traffic
              Optimization (ALTO) Problem Statement", RFC 5693,
              DOI 10.17487/RFC5693, October 2009,
              <http://www.rfc-editor.org/info/rfc5693>.

8.2.  Informative References

   [draft-ietf-alto-multi-cost]
              S. Randriamasy, W. Roome, N. Schwan, , "Multi-Cost ALTO
              (work in progress), draft-ietf-alto-multi-cost", May 2015.

   [draft-wu-alto-te-metrics]
              Q. Wu, Y. Yang, Y. Lee, D. Dhody, S. Randriamasy, , "ALTO
              Traffic Engineering Cost Metrics (work in progress)",
              October 2014.

   [draft-yang-alto-topology]
              Y. Yang, , "ALTO Topology Considerations (work in
              progress)", July 2013.

   [ID-alto-protocol]
              R.Alimi, R. Penno, Y. Yang, Eds., "ALTO Protocol, RFC
              7285", September 2014.

   [RFC7285]  R. Alimi, R. Yang, R. Penno, Eds., "ALTO Protocol",
              September 2014.

   [sdnrg]    "Software Defined Network Research Group,
              http://trac.tools.ietf.org/group/irtf/trac/wiki/sdnrg".

   [slides-88-alto-5-topology]
              G. Bernstein, Y. Lee, Y. Yang, , , "ALTO Topology Service:
              Use Cases, Requirements and Framework (presentation slides
              IETF88 ALTO WG session),
              http://tools.ietf.org/agenda/88/slides/
              slides-88-alto-5.pdf", November 2013.

Authors' Addresses

   Sabine Randriamasy
   Nokia Bell Labs
   Route de Villejust
   NOZAY  91460
   FRANCE

   Email: Sabine.Randriamasy@nokia-bell-labs.com





Randriamasy, et al.      Expires January 9, 2017               [Page 28]


Internet-Draft             ALTO Cost Calendar                  July 2016


   Richard Yang
   Yale University
   51 Prospect st
   New Haven, CT  06520
   USA

   Email: yry@cs.yale.edu


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

   Email: sunseawq@huawei.com


   Lingli Deng
   China Mobile
   China

   Email: denglingli@chinamobile.com


   Nico Schwan
   Thales Deutschland

   Email: nico.schwan@thalesgroup.com






















Randriamasy, et al.      Expires January 9, 2017               [Page 29]


Html markup produced by rfcmarkup 1.126, available from https://tools.ietf.org/tools/rfcmarkup/