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Versions: 00 01 02 03 04 05 06 07 08 09 10 11 RFC 5477

Network Working Group                                           T. Dietz
Internet-Draft                                           NEC Europe Ltd.
Intended status: Standards Track                             F. Dressler
Expires: April 14, 2008                 University of Erlangen-Nuremberg
                                                                G. Carle
                                                 University of Tuebingen
                                                               B. Claise
                                                               P. Aitken
                                                     Cisco Systems, Inc.
                                                        October 12, 2007


             Information Model for Packet Sampling Exports
                     <draft-ietf-psamp-info-07.txt>

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   Drafts.

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   The list of current Internet-Drafts can be accessed at
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   This Internet-Draft will expire on April 14, 2008.

Copyright Notice

   Copyright (C) The IETF Trust (2007).








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Abstract

   This memo defines an information model for the Packet Sampling
   (PSAMP) protocol.  It is used by the PSAMP protocol for encoding
   sampled packet data and information related to the sampling process.
   As the PSAMP protocol is based on the IPFIX protocol, this
   information model is an extension to the IPFIX information model.












































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Conventions used in this document

   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].


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  5

   2.  PSAMP Documents Overview . . . . . . . . . . . . . . . . . . .  6

   3.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  7
     3.1.  IPFIX Terminology  . . . . . . . . . . . . . . . . . . . .  7
     3.2.  PSAMP Terminology  . . . . . . . . . . . . . . . . . . . . 10

   4.  Relationship between PSAMP and IPFIX . . . . . . . . . . . . . 13

   5.  Properties of a PSAMP Information Element  . . . . . . . . . . 14

   6.  Type Space . . . . . . . . . . . . . . . . . . . . . . . . . . 15

   7.  Overloading Information Elements . . . . . . . . . . . . . . . 16

   8.  The PSAMP Information Elements . . . . . . . . . . . . . . . . 17
     8.1.  PSAMP Usage of IPFIX Attributes  . . . . . . . . . . . . . 17
     8.2.  Additional PSAMP Information Elements  . . . . . . . . . . 18
       8.2.1.  selectionSequenceId  . . . . . . . . . . . . . . . . . 18
       8.2.2.  selectorId . . . . . . . . . . . . . . . . . . . . . . 19
       8.2.3.  informationElementId . . . . . . . . . . . . . . . . . 19
       8.2.4.  selectorAlgorithm  . . . . . . . . . . . . . . . . . . 19
       8.2.5.  samplingPacketInterval . . . . . . . . . . . . . . . . 20
       8.2.6.  samplingPacketSpace  . . . . . . . . . . . . . . . . . 21
       8.2.7.  samplingTimeInterval . . . . . . . . . . . . . . . . . 21
       8.2.8.  samplingTimeSpace  . . . . . . . . . . . . . . . . . . 21
       8.2.9.  samplingSize . . . . . . . . . . . . . . . . . . . . . 22
       8.2.10. samplingPopulation . . . . . . . . . . . . . . . . . . 22
       8.2.11. samplingProbability  . . . . . . . . . . . . . . . . . 23
       8.2.12. dataLinkFrameSize  . . . . . . . . . . . . . . . . . . 23
       8.2.13. ipHeaderPacketSection  . . . . . . . . . . . . . . . . 23
       8.2.14. ipPayloadPacketSection . . . . . . . . . . . . . . . . 24
       8.2.15. dataLinkFrameSection . . . . . . . . . . . . . . . . . 25
       8.2.16. mplsLabelStackSection  . . . . . . . . . . . . . . . . 25
       8.2.17. mplsPayloadPacketSection . . . . . . . . . . . . . . . 26
       8.2.18. SelectorIdTotalPacketsObserved . . . . . . . . . . . . 26
       8.2.19. SelectorIdTotalPacketsSelected . . . . . . . . . . . . 27
       8.2.20. fixedError . . . . . . . . . . . . . . . . . . . . . . 27



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       8.2.21. relativeError  . . . . . . . . . . . . . . . . . . . . 27
       8.2.22. observationTimeSeconds . . . . . . . . . . . . . . . . 28
       8.2.23. observationTimeMilliseconds  . . . . . . . . . . . . . 28
       8.2.24. observationTimeMicroseconds  . . . . . . . . . . . . . 28
       8.2.25. observationTimeNanoseconds . . . . . . . . . . . . . . 29
       8.2.26. digestHashValue  . . . . . . . . . . . . . . . . . . . 29
       8.2.27. hashIPPayloadOffset  . . . . . . . . . . . . . . . . . 29
       8.2.28. hashIPPayloadSize  . . . . . . . . . . . . . . . . . . 30
       8.2.29. hashOutputRangeMin . . . . . . . . . . . . . . . . . . 30
       8.2.30. hashOutputRangeMax . . . . . . . . . . . . . . . . . . 30
       8.2.31. hashSelectedRangeMin . . . . . . . . . . . . . . . . . 30
       8.2.32. hashSelectedRangeMax . . . . . . . . . . . . . . . . . 31
       8.2.33. hashDigestOutput . . . . . . . . . . . . . . . . . . . 31
       8.2.34. hashInitialiserValue . . . . . . . . . . . . . . . . . 31

   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 33

   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 34

   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 35
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 35
     11.2. Informative References . . . . . . . . . . . . . . . . . . 35

   Appendix A.  Formal Specification of PSAMP Information Elements  . 37

   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 49
   Intellectual Property and Copyright Statements . . . . . . . . . . 51
























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1.  Introduction

   Packet sampling techniques are required for various measurement
   scenarios.  The packet sampling (PSAMP) protocol provides mechanisms
   for packet selection using different filtering and sampling
   techniques.  A standard way for the export and storage is required.
   The definition of the PSAMP information and data model is based on
   the IP Flow Information eXport (IPFIX) protocol
   [I-D.ietf-ipfix-protocol].  The PSAMP protocol document
   [I-D.ietf-psamp-protocol] specifies how to use the IPFIX protocol in
   the PSAMP context.

   This document examines the IPFIX information model
   [I-D.ietf-ipfix-info] and extends it to meet the PSAMP requirements.
   Therefore, the structure of this document is strongly based on the
   IPFIX document.  It complements the PSAMP protocol specification by
   providing an appropriate PSAMP information model.  The main part of
   this document, section 8, defines the list of Information Elements to
   be transmitted by the PSAMP protocol.  Sections 6 and 5 describe the
   data types and Information Element properties used within this
   document and their relationship to the IPFIX information model.

   The main body of section 8 was generated from a XML document.  The
   XML-based specification of the PSAMP Information Elements can be used
   for automatically checking syntactical correctness of the
   specification.  Furthermore it can be used - in combination with the
   IPFIX information model - for automated code generation.  The
   resulting code can be used in PSAMP protocol implementations to deal
   with processing PSAMP information elements.

   For that reason, the XML document that served as source for section 8
   is attached to this document in Appendix A.

   Note that although partially generated from the attached XML
   documents, the main body of this document is normative while the
   appendices are informational.















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2.  PSAMP Documents Overview

   [I-D.ietf-psamp-framework]: "A Framework for Packet Selection and
   Reporting", describes the PSAMP framework for network elements to
   select subsets of packets by statistical and other methods, and to
   export a stream of reports on the selected packets to a collector.

   [I-D.ietf-psamp-sample-tech]: "Sampling and Filtering Techniques for
   IP Packet Selection", describes the set of packet selection
   techniques supported by PSAMP.

   [I-D.ietf-psamp-protocol]: "Packet Sampling (PSAMP) Protocol
   Specifications" specifies the export of packet information from a
   PSAMP Exporting Process to a PSAMP Collecting Process.

   This Document: "Information Model for Packet Sampling Exports" (this
   document), defines an information and data model for PSAMP.


































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3.  Terminology

   As the IPFIX export protocol is used to export the PSAMP information,
   the relevant IPFIX terminology from [I-D.ietf-ipfix-protocol] is
   copied over in this document.  The PSAMP terminology defined here is
   fully consistent with all terms listed in [I-D.ietf-psamp-protocol]
   but only definitions that are relevant to the PSAMP information model
   appear here.

3.1.  IPFIX Terminology

   The IPFIX terminology section has been entirely copied over from
   [I-D.ietf-ipfix-protocol], except for the IPFIX Exporting Process
   term, which is defined more precisely in the PSAMP terminology
   section.

   o  Observation Point

      An Observation Point is a location in the network where IP packets
      can be observed.  Examples include: a line to which a probe is
      attached, a shared medium, such as an Ethernet-based LAN, a single
      port of a router, or a set of interfaces (physical or logical) of
      a router.

      Note that every Observation Point is associated with an
      Observation Domain (defined below), and that one Observation Point
      may be a superset of several other Observation Points.  For
      example one Observation Point can be an entire line card.  That
      would be the superset of the individual Observation Points at the
      line card's interfaces.

   o  Observation Domain

      An Observation Domain is the largest set of Observation Points for
      which Flow information can be aggregated by a Metering Process.

   o  IP Traffic Flow or Flow

      There are several definitions of the term 'flow' being used by the
      Internet community.  Within the context of IPFIX we use the
      following definition:

      A Flow is defined as a set of IP packets passing an Observation
      Point in the network during a certain time interval.  All packets
      belonging to a particular Flow have a set of common properties.
      Each property is defined as the result of applying a function to
      the values of:




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      1.  one or more packet header field (e.g. destination IP address),
          transport header field (e.g. destination port number), or
          application header field (e.g.  RTP header fields [RFC3550])

      2.  one or more characteristics of the packet itself (e.g. number
          of MPLS labels, etc...)

      3.  one or more of fields derived from packet treatment (e.g. next
          hop IP address, the output interface, etc...)

      A packet is defined to belong to a Flow if it completely satisfies
      all the defined properties of the Flow.

      This definition covers the range from a Flow containing all
      packets observed at a network interface to a Flow consisting of
      just a single packet between two applications.  It includes
      packets selected by a sampling mechanism.

   o  Flow Record

      A Flow Record contains information about a specific Flow that was
      observed at an Observation Point.  A Flow Record contains measured
      properties of the Flow (e.g. the total number of bytes for all the
      Flow's packets) and usually characteristic properties of the Flow
      (e.g. source IP address).

   o  Metering Process

      The Metering Process generates Flow Records.  Inputs to the
      process are packet headers and characteristics observed at an
      Observation Point, and packet treatment at the Observation Point
      (for example the selected output interface).

      The Metering Process consists of a set of functions that includes
      packet header capturing, timestamping, sampling, classifying, and
      maintaining Flow Records.

      The maintenance of Flow Records may include creating new records,
      updating existing ones, computing Flow statistics, deriving
      further Flow properties, detecting Flow expiration, passing Flow
      Records to the Exporting Process, and deleting Flow Records.

   o  IPFIX Device

      An IPFIX Device hosts at least one Exporting Process.  It may host
      further Exporting processes and arbitrary numbers of Observation
      Points and Metering Process.




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   o  Exporting Process

      An Exporting Process sends, in the form of Export Packets, the
      output of one or more Metering Processes to one or more
      Collectors.

   o  Collecting Process

      A Collecting Process receives Flow Records from one or more
      Exporting Processes.  The Collecting Process might process or
      store received Flow Records, but such actions are out of scope for
      this document.

   o  Collector

      A device which hosts one or more Collecting Processes is termed a
      Collector.

   o  Template

      A Template is an ordered sequence of <type, length> pairs, used to
      completely specify the structure and semantics of a particular set
      of information that needs to be communicated from an IPFIX Device
      to a Collector.  Each Template is uniquely identifiable by means
      of a Template ID.

   o  Template Record

      A Template Record defines the structure and interpretation of
      fields in a Data Record.

   o  Data Record

      A Data Record is a record that contains values of the parameters
      corresponding to a Template Record.

   o  Options Template Record

      An Options Template Record is a Template Record that defines the
      structure and interpretation of fields in a Data Record, including
      defining how to scope the applicability of the Data Record.

   o  Information Element

      An Information Element is a protocol and encoding independent
      description of an attribute which may appear in an IPFIX Record.





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3.2.  PSAMP Terminology

   The relevant PSAMP terminology has been copied from
   [I-D.ietf-psamp-protocol] into this document.

   o  Observed Packet Stream

      An Observed Packet Stream denotes the packets that flow past the
      Observation Point.

   o  Packet Stream

      A Packet Stream denotes a subset of the Observed Packet Stream
      that flows past some specified point within the Selection Process.
      An example of a Packet Stream is the output of the Selection
      Process.  Note that packets selected from a stream, e.g. by
      Sampling, do not necessarily possess a property by which they can
      be distinguished from packets that have not been selected.  For
      this reason the term "stream" is favored over "flow", which is
      defined as a set of packets with common properties [RFC3917].

   o  Selection Process

      A Selection Process takes the Observed Packet Stream as its input
      and selects a subset of that stream as its output.

   o  Population

      A Population is a Packet Stream, or a subset of a Packet Stream.
      A Population can be considered as a base set from which packets
      are selected.  An example is all packets in the Observed Packet
      Stream that are observed within some specified time interval.

   o  Selector

      A Selector defines the action of a Selection Process on a single
      packet of its input.  If selected, the packet becomes an element
      of the output Packet Stream.

      The Selector can make use of the following information in
      determining whether a packet is selected:

      1.  the Packet Content;

      2.  information derived from the packet's treatment at the
          Observation Point;





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      3.  any selection state that may be maintained by the Selection
          Process.

   o  Composite Selector

      A Composite Selector is an ordered composition of Selectors, in
      which the output Packet Stream issuing from one Selector forms the
      input Packet Stream to the succeeding Selector.

   o  Primitive Selector

      A Selector is primitive if it is not a Composite Selector.

   o  Selector ID

      The Selector ID is the unique ID identifying a Primitive Selector.
      The ID is unique within the Observation Domain.

   o  Selection Sequence

      From all the packets observed at an Observation Point, only a few
      packets are selected by one or more Selectors.  The Selection
      Sequence is a unique value per Observation Domain describing the
      Observation Point and the Selector IDs through which the packets
      are selected.

   o  Packet Reports

      Packet Reports comprise a configurable subset of a packet's input
      to the Selection Process, including the Packet Content,
      information relating to its treatment (for example, the output
      interface), and its associated selection state (for example, a
      hash of the Packet Content).

   o  Report Interpretation

      Report Interpretation comprises subsidiary information, relating
      to one or more packets, that are used for interpretation of their
      Packet Reports.  Examples include configuration parameters of the
      Selection Process.

   o  PSAMP Device

      A PSAMP Device is a device hosting at least an Observation Point,
      a Selection Process and an Exporting Process.  Typically,
      corresponding Observation Point(s), Selection Process(es) and
      Exporting Process(es) are co-located at this device, for example
      at a router.



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   o  Filtering

      A filter is a Selector that selects a packet deterministically
      based on the Packet Content, or its treatment, or functions of
      these occurring in the Selection State.  Examples include property
      match Filtering, and Hash-based Selection.

   o  Sampling

      A Selector that is not a filter is called a Sampling operation.
      This reflects the intuitive notion that if the selection of a
      packet cannot be determined from its content alone, there must be
      some type of Sampling taking place.






































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4.  Relationship between PSAMP and IPFIX

   As described in the PSAMP protocol draft [I-D.ietf-psamp-protocol] a
   PSAMP Report can be seen as a very special IPFIX Data Record.  It
   represents an IPFIX Flow containing only a single packet.  Therefore,
   the IPFIX information model can be used as a basis for PSAMP Reports.

   Nevertheless, there are properties required in PSAMP Reports which
   cannot be modelled using the current IPFIX information model.  This
   document describes extensions to the IPFIX information model which
   allow the modelling of information and data required by PSAMP.

   Some of these extensions allow the export of what may be considered
   sensitive information.  Refer to the Security Considerations section
   for a fuller discussion.

   Note that the export of sampled or filtered PSAMP Reports may not
   need all the Information Elements defined by the IPFIX information
   model [I-D.ietf-ipfix-info], as discussed in sections 6.2 and 6.3 of
   the PSAMP Framework [I-D.ietf-psamp-framework].































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5.  Properties of a PSAMP Information Element

   The PSAMP Information Elements are in accordance with the definitions
   of IPFIX.  Therefore we do not repeat the properties in this draft.
   Refer to sections 2.1 through 2.3 of the IPFIX Information Model
   [I-D.ietf-ipfix-info].  Nevertheless, we strongly recommend defining
   the optional "units" property for every information element (if
   applicable).











































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6.  Type Space

   The PSAMP Information Elements MUST be constructed from the basic
   data types described in section 3 of the IPFIX Information Model
   [I-D.ietf-ipfix-info].  To avoid duplicated work and to keep
   consistency between IPFIX and PSAMP, the data types are not repeated
   in this document.












































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7.  Overloading Information Elements

   Information Elements SHOULD NOT be overloaded with multiple meanings
   or re-used for multiple purposes.  Different Information Elements
   SHOULD be allocated for each requirement.

   In particular, special information SHALL be encoded in new
   Information Elements as necessary, and SHALL NOT be encoded in the
   selection method.

   Although the presence of certain other Information Elements allows
   the selection method to be inferred, a separate Information Element
   is provided for the selectorAlgorithm, e.g. for including in scope
   info and depicting the contents of composites.

   Even if the Information Elements are specified with a specific
   selection method (i.e. a specific value of selectorAlgorithm) in
   mind, these Information Elements are not restricted to the selection
   method and MAY be used for different selection methods in the future.
































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8.  The PSAMP Information Elements

   This section describes the Information Elements used by the PSAMP
   protocol.

   Each Information Element specified in section 8.2 below is allocated
   a unique identifier in accordance with section 5 of the IPFIX
   information model [I-D.ietf-ipfix-info].  The assignments are
   controlled by IANA as an extension of the IPFIX Information Model.

   The Information Elements specified by the IPFIX information model
   [I-D.ietf-ipfix-info] are used by the PSAMP protocol where
   applicable.  To avoid inconsistencies between the IPFIX and the PSAMP
   information and data models, only those Information Elements that are
   not already described by the IPFIX information model are defined
   here.

8.1.  PSAMP Usage of IPFIX Attributes

   This section lists additional Information Elements that are needed in
   the PSAMP context and introduces their usage.

   List of additional PSAMP Information Elements:




























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   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   | 301 | selectionSequenceId       | 318 | SelectorIdTotalPacketsObs |
   |     |                           |     | erved                     |
   | 302 | selectorId                | 319 | SelectorIdTotalPacketsSel |
   |     |                           |     | ected                     |
   | 303 | informationElementId      | 320 | fixedError                |
   | 304 | selectorAlgorithm         | 321 | relativeError             |
   | 305 | samplingPacketInterval    | 322 | observationTimeSeconds    |
   |     |                           |     |                           |
   | 306 | samplingPacketSpace       | 323 | observationTimeMillisecon |
   |     |                           |     | ds                        |
   | 307 | samplingTimeInterval      | 324 | observationTimeMicrosecon |
   |     |                           |     | ds                        |
   | 308 | samplingTimeSpace         | 325 | observationTimeNanosecond |
   |     |                           |     | s                         |
   | 309 | samplingSize              | 326 | digestHashValue           |
   | 310 | samplingPopulation        | 327 | hashIPPayloadOffset       |
   | 311 | samplingProbability       | 328 | hashIPPayloadSize         |
   | 312 | dataLinkFrameSize         | 329 | hashOutputRangeMin        |
   | 313 | ipHeaderPacketSection     | 330 | hashOutputRangeMax        |
   |     |                           |     |                           |
   | 314 | ipPayloadPacketSection    | 331 | hashSelectedRangeMin      |
   |     |                           |     |                           |
   | 315 | dataLinkFrameSection      | 332 | hashSelectedRangeMax      |
   | 316 | mplsLabelStackSection     | 333 | hashDigestOutput          |
   |     |                           |     |                           |
   | 317 | mplsPayloadPacketSection  | 334 | hashInitialiserValue      |
   |     |                           |     |                           |
   +-----+---------------------------+-----+---------------------------+

8.2.  Additional PSAMP Information Elements

8.2.1.  selectionSequenceId

   Description:

      From all the packets observed at an Observation Point, a subset of
      packets is selected by a sequence of one or more Selectors.  The
      selectionSequenceId is a unique value per Observation Domain,
      specifying the Observation Point and the sequence of Selectors
      through which the packets are selected.

   Abstract Data Type:  unsigned64






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   ElementId:  301

   Status:  current

8.2.2.  selectorId

   Description:

      The Selector ID is the unique ID identifying a Primitive Selector.
      Each Primitive Selector must have a unique ID in the Observation
      Domain.

   Abstract Data Type:  unsigned16

   Data Type Semantics:  identifier

   ElementId:  302

   Status:  current

8.2.3.  informationElementId

   Description:

      This Information Element contains the ID of another Information
      Element.

   Abstract Data Type:  unsigned16

   Data Type Semantics:  identifier

   ElementId:  303

   Status:  current

8.2.4.  selectorAlgorithm

   Description:

      This Information Element specifies the Selector algorithm (e.g.,
      Filtering, Sampling) that was used on a packet.

      The following Selector algorithms are currently defined:

      1 Systematic count-based Sampling






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      2 Systematic time-based Sampling

      3 Random n-out-of-N Sampling

      4 Uniform probabilistic Sampling

      5 Property match Filtering

      6 Hash based Filtering using BOB

      7 Hash based Filtering using IPSX

      8 Hash based Filtering using CRC

      The parameters for most of these algorithms are defined in this
      information model.  Some parameters for these algorithms are not
      covered by this information model since they very much depend on
      the underlying hardware.

      This list will be maintained by IANA.  IANA can update this
      Information Element as long as there's a new RFC specifying the
      algorithm and any new Information Elements which are required.

   Abstract Data Type:  unsigned16

   Data Type Semantics:  identifier

   ElementId:  304

   Status:  current

8.2.5.  samplingPacketInterval

   Description:

      This Information Element specifies the number of packets that are
      consecutively sampled.  For example a value of 100 means that 100
      contiguous packets are sampled.

      For example, this Information Element may be used to describe the
      configuration of a systematic count-based sampling Selector.

   Abstract Data Type:  unsigned32

   ElementId:  305






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   Status:  current

   Units:  packets

8.2.6.  samplingPacketSpace

   Description:

      This Information Element specifies the number of packets between
      two "samplingPacketInterval"s.  A value of 100 means that the next
      interval starts after 100 packets (which are not sampled) when the
      current "samplingPacketInterval" is over.

      For example, this Information Element may be used to describe the
      configuration of a systematic count-based sampling Selector.

   Abstract Data Type:  unsigned32

   ElementId:  306

   Status:  current

   Units:  packets

8.2.7.  samplingTimeInterval

   Description:

      This Information Element specifies the time interval in
      microseconds during which all arriving packets are sampled.

      For example, this Information Element may be used to describe the
      configuration of a systematic time-based sampling Selector.

   Abstract Data Type:  dateTimeMicroseconds

   ElementId:  307

   Status:  current

   Units:  microseconds

8.2.8.  samplingTimeSpace








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   Description:

      This Information Element specifies the time interval in
      microseconds between two "samplingTimeInterval"s.  A value of 100
      means that the next interval starts after 100 microseconds (during
      which no packets are sampled) when the current
      "samplingTimeInterval" is over.

      For example, this Information Element may used to describe the
      configuration of a systematic time-based sampling Selector.

   Abstract Data Type:  dateTimeMicroseconds

   ElementId:  308

   Status:  current

   Units:  microseconds

8.2.9.  samplingSize

   Description:

      This Information Element specifies the number of elements taken
      from the parent Population for random sampling algorithms.

      For example, this Information Element may be used to describe the
      configuration of a random n-out-of-N sampling Selector.

   Abstract Data Type:  unsigned32

   ElementId:  309

   Status:  current

   Units:  packets

8.2.10.  samplingPopulation

   Description:

      This Information Element specifies the number of elements in the
      parent Population for random sampling algorithms.

      For example, this Information Element may be used to describe the
      configuration of a random n-out-of-N sampling Selector.





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   Abstract Data Type:  unsigned32

   ElementId:  310

   Status:  current

   Units:  packets

8.2.11.  samplingProbability

   Description:

      This Information Element specifies the probability that a packet
      is sampled, expressed as a value between 0 and 1.  The probability
      is equal for every packet.  A value of 0 means no packet was
      sampled since the probability is 0.

      For example, this Information Element may be used to describe the
      configuration of a uniform probabilistic sampling Selector.

   Abstract Data Type:  float64

   ElementId:  311

   Status:  current

8.2.12.  dataLinkFrameSize

   Description:

      This Information Element specifies the size of the sampled data
      link frame, and SHOULD be checked before analysing higher layer
      protocols.

      The data link layer is defined in [ISO_IEC.7498-1_1994].

   Abstract Data Type:  unsigned32

   ElementId:  312

   Status:  current

8.2.13.  ipHeaderPacketSection








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   Description:

      This Information Element, which may have a variable length,
      carries a series of octets from the start of the IP header of a
      sampled packet.

      With sufficient length, this element also reports octets from the
      IP payload, subject to [RFC2804].  See the Security Considerations
      section.

      The size of the exported section may be constrained due to
      limitations in the IPFIX protocol.

      If insufficient octets are available for the length specified in
      the Template, the Information Element MUST NOT be padded.

   Abstract Data Type:  octetArray

   ElementId:  313

   Status:  current

8.2.14.  ipPayloadPacketSection

   Description:

      This Information Element, which may have a variable length,
      carries a series of octets from the start of the IP payload of a
      sampled packet.

      The IPv4 payload is that part of the packet which follows the IPv4
      header and any options, which [RFC0791] refers to as "data" or
      "data octets". e.g., see the examples in [RFC0791] APPENDIX A.

      The IPv6 payload is the rest of the packet following the 40 octet
      IPv6 header.  Note that any extension headers present are
      considered part of the payload.  See [RFC2460] for the IPv6
      specification.

      The size of the exported section may be constrained due to
      limitations in the IPFIX protocol.

      If insufficient octets are available for the length specified in
      the Template, the Information Element MUST NOT be padded.







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   Abstract Data Type:  octetArray

   ElementId:  314

   Status:  current

8.2.15.  dataLinkFrameSection

   Description:

      This Information Element, which may have a variable length,
      carries the first n octets from the data link frame of a sampled
      packet.

      The data link layer is defined in [ISO_IEC.7498-1_1994].

      The size of the exported section may be constrained due to
      limitations in the IPFIX protocol.

      If insufficient octets are available for the length specified in
      the Template, the Information Element MUST NOT be padded.

   Abstract Data Type:  octetArray

   ElementId:  315

   Status:  current

8.2.16.  mplsLabelStackSection

   Description:

      This Information Element, which may have a variable length,
      carries the first n octets from the MPLS label stack of a sampled
      packet.

      With sufficient length, this element also reports octets from the
      MPLS payload, subject to [RFC2804].  See the Security
      Considerations section.

      See [RFC3031] for the specification of MPLS packets.

      See [RFC3032] for the specification of the MPLS label stack.

      The size of the exported section may be constrained due to
      limitations in the IPFIX protocol.





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      If insufficient octets are available for the length specified in
      the Template, the Information Element MUST NOT be padded.

   Abstract Data Type:  octetArray

   ElementId:  316

   Status:  current

8.2.17.  mplsPayloadPacketSection

   Description:

      This Information Element, which may have a variable length,
      carries the first n octets from the MPLS payload of a sampled
      packet, being data that follows immediately after the MPLS label
      stack.

      See [RFC3031] for the specification of MPLS packets.

      See [RFC3032] for the specification of the MPLS label stack.

      The size of the exported section may be constrained due to
      limitations in the IPFIX protocol.

      If insufficient octets are available for the length specified in
      the Template, the Information Element MUST NOT be padded.

   Abstract Data Type:  octetArray

   ElementId:  317

   Status:  current

8.2.18.  SelectorIdTotalPacketsObserved

   Description:

      This Information Element specifies the total number of packets
      observed by a Selector, for a specific value of SelectorId.

   Abstract Data Type:  unsigned64

   Data Type Semantics:  totalCounter







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   ElementId:  318

   Status:  current

   Units:  packets

8.2.19.  SelectorIdTotalPacketsSelected

   Description:

      This Information Element specifies the total number of packets
      selected by a Selector, for a specific value of SelectorId.

   Abstract Data Type:  unsigned64

   Data Type Semantics:  totalCounter

   ElementId:  319

   Status:  current

   Units:  packets

8.2.20.  fixedError

   Description:

      This Information Element specifies the maximum possible positive
      or negative error interval of the reported value for a given
      Information Element.

   Abstract Data Type:  float64

   ElementId:  320

   Status:  current

   Units:  The units of the Information Element for which the error is
      specified.

8.2.21.  relativeError

   Description:

      This Information Element specifies the maximum possible positive
      or negative error ratio for a given Information Element.





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   Abstract Data Type:  float64

   ElementId:  321

   Status:  current

8.2.22.  observationTimeSeconds

   Description:

      This Information Element specifies the absolute time in seconds of
      an observation.

   Abstract Data Type:  dateTimeSeconds

   ElementId:  322

   Status:  current

   Units:  seconds

8.2.23.  observationTimeMilliseconds

   Description:

      This Information Element specifies the absolute time in
      milliseconds of an observation.

   Abstract Data Type:  dateTimeMilliseconds

   ElementId:  323

   Status:  current

   Units:  milliseconds

8.2.24.  observationTimeMicroseconds

   Description:

      This Information Element specifies the absolute time in
      microseconds of an observation.

   Abstract Data Type:  dateTimeMicroseconds







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   ElementId:  324

   Status:  current

   Units:  microseconds

8.2.25.  observationTimeNanoseconds

   Description:

      This Information Element specifies the absolute time in
      nanoseconds of an observation.

   Abstract Data Type:  dateTimeNanoseconds

   ElementId:  325

   Status:  current

   Units:  nanoseconds

8.2.26.  digestHashValue

   Description:

      This Information Element specifies the value from the digest hash
      function.

   Abstract Data Type:  unsigned64

   ElementId:  326

   Status:  current

8.2.27.  hashIPPayloadOffset

   Description:

      This Information Element specifies the IP payload offset used by a
      hash based Selector.

   Abstract Data Type:  unsigned64

   ElementId:  327







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   Status:  current

8.2.28.  hashIPPayloadSize

   Description:

      This Information Element specifies the IP payload size used by a
      hash based Selector.

   Abstract Data Type:  unsigned64

   ElementId:  328

   Status:  current

8.2.29.  hashOutputRangeMin

   Description:

      This Information Element specifies the value for the beginning of
      a hash function's potential output range.

   Abstract Data Type:  unsigned64

   ElementId:  329

   Status:  current

8.2.30.  hashOutputRangeMax

   Description:

      This Information Element specifies the value for the end of a hash
      function's potential output range.

   Abstract Data Type:  unsigned64

   ElementId:  330

   Status:  current

8.2.31.  hashSelectedRangeMin

   Description:







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      This Information Element specifies the value for the beginning of
      a hash function's selected range.

   Abstract Data Type:  unsigned64

   ElementId:  331

   Status:  current

8.2.32.  hashSelectedRangeMax

   Description:

      This Information Element specifies the value for the end of a hash
      function's selected range.

   Abstract Data Type:  unsigned64

   ElementId:  332

   Status:  current

8.2.33.  hashDigestOutput

   Description:

      This Information Element contains a boolean value which is TRUE if
      the output from this hash Selector has been configured to be
      included in the packet report as a packet digest, else FALSE.

   Abstract Data Type:  boolean

   ElementId:  333

   Status:  current

8.2.34.  hashInitialiserValue

   Description:

      This Information Element specifies the initialiser value to the
      hash function.

   Abstract Data Type:  unsigned64







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   ElementId:  334

   Status:  current
















































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9.  Security Considerations

   The PSAMP information model itself does not directly introduce
   security issues.  Rather it defines a set of attributes which may for
   privacy or business issues be considered sensitive information.

   Specifically, the Information Elements pertaining to packet sections
   MUST target no more than the packet header, some subsequent bytes of
   the packet, and encapsulating headers if present.  Full packet
   capture of arbitrary packet streams is explicitly out of scope, per
   [RFC2804].

   The underlying protocol used to exchange the information described
   here must therefore apply appropriate procedures to guarantee the
   integrity and confidentiality of the exported information.  Such
   protocols are defined in separate documents, specifically the PSAMP
   protocol document [I-D.ietf-psamp-protocol].


































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10.  IANA Considerations

   This document specifies an initial set of PSAMP Information Elements
   as specified in [I-D.ietf-psamp-sample-tech], as an extension to the
   IPFIX Information Elements [I-D.ietf-ipfix-info].  New assignments
   for PSAMP Information Elements will be administered according to
   rules explained in the "IANA Consideration" section of the IPFIX
   Information Model document [I-D.ietf-ipfix-info].

   Note that the PSAMP Information Element IDs were initially started at
   the value 301, in order to leave a gap for any ongoing IPFIX work
   requiring new Information Elements.  It is expected that this gap in
   the Information Element numbering will be filled in by IANA with new
   IPFIX Information Elements.

   Appendix B defines an XML schema which may be used to create
   consistent machine readable extensions to the IPFIX information
   model.  This schema introduces a new namespace, which will be
   assigned by IANA according to [RFC3688].

   The selectorAlgorithm registry is maintained by IANA and can be
   updated as long as specifications of the new method(s) and any new
   Information Elements are provided.




























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11.  References

11.1.  Normative References

   [I-D.ietf-psamp-sample-tech]
              Zseby, T., "Sampling and Filtering Techniques for IP
              Packet Selection", draft-ietf-psamp-sample-tech-10 (work
              in progress), June 2007.

   [I-D.ietf-psamp-protocol]
              Claise, B., "Packet Sampling (PSAMP) Protocol
              Specifications", draft-ietf-psamp-protocol-08 (work in
              progress), June 2007.

   [I-D.ietf-ipfix-info]
              Quittek, J., "Information Model for IP Flow Information
              Export", draft-ietf-ipfix-info-15 (work in progress),
              February 2007.

   [I-D.ietf-ipfix-protocol]
              Claise, B., "Specification of the IPFIX Protocol for the
              Exchange of IP Traffic Flow  Information",
              draft-ietf-ipfix-protocol-26 (work in progress),
              September 2007.

   [ISO_IEC.7498-1_1994]
              International Organization for Standardization,
              "Information technology -- Open Systems Interconnection --
              Basic Reference Model: The Basic Mode", ISO Standard 7498-
              1:1994, June 1996.

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

11.2.  Informative References

   [RFC3917]  Quittek, J., Zseby, T., Claise, B., and S. Zander,
              "Requirements for IP Flow Information Export (IPFIX)",
              RFC 3917, October 2004.

   [I-D.ietf-psamp-framework]
              Duffield, N., "A Framework for Packet Selection and
              Reporting", draft-ietf-psamp-framework-12 (work in
              progress), June 2007.

   [RFC2804]  IAB and IESG, "IETF Policy on Wiretapping", RFC 2804,
              May 2000.




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   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              September 1981.

   [RFC2460]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", RFC 2460, December 1998.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031, January 2001.

   [RFC3032]  Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
              Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
              Encoding", RFC 3032, January 2001.

   [RFC2629]  Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
              June 1999.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC3550]  Schulzrinne, H., Casner, S., Frederick, R., and V.
              Jacobson, "RTP: A Transport Protocol for Real-Time
              Applications", STD 64, RFC 3550, July 2003.





























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Appendix A.  Formal Specification of PSAMP Information Elements

   This appendix contains a formal description of the PSAMP information
   model XML document.  Note that this appendix is of informational
   nature, while the text in section Section 8 generated from this
   appendix is normative.

   Using a formal and machine readable syntax for the information model
   enables the creation of PSAMP aware tools which can automatically
   adapt to extensions to the information model, by simply reading
   updated information model specifications.

   The wide availability of XML aware tools and libraries for client
   devices is a primary consideration for this choice.  In particular
   libraries for parsing XML documents are readily available.  Also
   mechanisms such as the Extensible Stylesheet Language (XSL) allow for
   transforming a source XML document into other documents.  This draft
   was authored in XML and transformed according to [RFC2629].

   It should be noted that the use of XML in exporters, collectors or
   other tools is not mandatory for the deployment of PSAMP.  In
   particular, exporting processes do not produce or consume XML as part
   of their operation.  It is expected that PSAMP collectors MAY take
   advantage of the machine readability of the information model vs.
   hardcoding their behavior or inventing proprietary means for
   accommodating extensions.

   Using XML-based specifications does not currently address possible
   IANA implications associated with XML Namespace URIs.  The use of
   Namespaces as an extension mechanism implies that an IANA registered
   Namespace URI should be available and that directory names below this
   base URI be assigned for relevant IETF specifications.  The authors
   are not aware of this mechanism today.

<?xml version="1.0" encoding="UTF-8"?>
<fieldDefinitions xmlns="urn:ietf:params:xml:ns:ipfix-info"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="urn:ietf:params:xml:ns:ipfix-info
             ipfix-info.xsd">
  <field name="selectionSequenceId" dataType="unsigned64"
    elementId="301" status="current" group="common">
    <description>
      <paragraph>
        From all the packets observed at an Observation Point, a subset
        of packets is selected by a sequence of one or more Selectors.
        The selectionSequenceId is a unique value per Observation
        Domain, specifying the Observation Point and the sequence of
        Selectors through which the packets are selected.



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      </paragraph>
    </description>
  </field>

  <field name="selectorId" dataType="unsigned16"
    dataTypeSemantics="identifier" elementId="302" status="current"
    group="common">
    <description>
      <paragraph>
        The Selector ID is the unique ID identifying a Primitive
        Selector. Each Primitive Selector must have a unique ID in the
        Observation Domain.
      </paragraph>
    </description>
  </field>

  <field name="informationElementId" dataType="unsigned16"
    dataTypeSemantics="identifier" elementId="303" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element contains the ID of another Information
        Element.
      </paragraph>
    </description>
  </field>

  <field name="selectorAlgorithm" dataType="unsigned16"
    dataTypeSemantics="identifier" elementId="304" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element specifies the Selector algorithm (e.g.,
        Filtering, Sampling) that was used on a packet.

        The following Selector algorithms are currently defined:

        1 Systematic count-based Sampling

        2 Systematic time-based Sampling

        3 Random n-out-of-N Sampling

        4 Uniform probabilistic Sampling

        5 Property match Filtering

        6 Hash based Filtering using BOB



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        7 Hash based Filtering using IPSX

        8 Hash based Filtering using CRC

        The parameters for most of these algorithms are defined in this
        information model. Some parameters for these algorithms are not
        covered by this information model since they very much depend on
        the underlying hardware.


        This list will be maintained by IANA. IANA can update this
        Information Element as long as there's a new RFC specifying the
        algorithm and any new Information Elements which are required.
      </paragraph>
    </description>
  </field>

  <field name="samplingPacketInterval" dataType="unsigned32"
    elementId="305" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the number of packets that
        are consecutively sampled. For example a value of 100 means that
        100 contiguous packets are sampled.

        For example, this Information Element may be used to describe
        the configuration of a systematic count-based sampling Selector.
      </paragraph>
    </description>
    <units>packets</units>
  </field>

  <field name="samplingPacketSpace" dataType="unsigned32"
    elementId="306" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the number of packets between
        two "samplingPacketInterval"s. A value of 100 means that the
        next interval starts after 100 packets (which are not sampled)
        when the current "samplingPacketInterval" is over.

        For example, this Information Element may be used to describe
        the configuration of a systematic count-based sampling Selector.
      </paragraph>
    </description>
    <units>packets</units>
  </field>




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  <field name="samplingTimeInterval" dataType="dateTimeMicroseconds"
    elementId="307" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the time interval in
        microseconds during which all arriving packets are sampled.

        For example, this Information Element may be used to describe
        the configuration of a systematic time-based sampling Selector.
      </paragraph>
    </description>
    <units>microseconds</units>
  </field>

  <field name="samplingTimeSpace" dataType="dateTimeMicroseconds"
    elementId="308" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the time interval in
        microseconds between two "samplingTimeInterval"s. A value of 100
        means that the next interval starts after 100 microseconds
        (during which no packets are sampled) when the current
        "samplingTimeInterval" is over.

        For example, this Information Element may used to describe the
        configuration of a systematic time-based sampling Selector.
      </paragraph>
    </description>
    <units>microseconds</units>
  </field>

  <field name="samplingSize" dataType="unsigned32" elementId="309"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the number of elements taken
        from the parent Population for random sampling algorithms.

        For example, this Information Element may be used to describe
        the configuration of a random n-out-of-N sampling Selector.
      </paragraph>
    </description>
    <units>packets</units>
  </field>

  <field name="samplingPopulation" dataType="unsigned32" elementId="310"
    status="current" group="common">
    <description>



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      <paragraph>
        This Information Element specifies the number of elements in the
        parent Population for random sampling algorithms.

        For example, this Information Element may be used to describe
        the configuration of a random n-out-of-N sampling Selector.
      </paragraph>
    </description>
    <units>packets</units>
  </field>

  <field name="samplingProbability" dataType="float64" elementId="311"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the probability that a packet
        is sampled, expressed as a value between 0 and 1. The
        probability is equal for every packet. A value of 0 means no
        packet was sampled since the probability is 0.

        For example, this Information Element may be used to describe
        the configuration of a uniform probabilistic sampling Selector.
      </paragraph>
    </description>
  </field>

  <field name="dataLinkFrameSize" dataType="unsigned32" elementId="312"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the size of the sampled data
        link frame, and SHOULD be checked before analysing higher layer
        protocols.

        The data link layer is defined in [ISO_IEC.7498-1_1994].
      </paragraph>
    </description>
  </field>

  <field name="ipHeaderPacketSection" dataType="octetArray"
    elementId="313" status="current" group="common">
    <description>
      <paragraph>
        This Information Element, which may have a variable length,
        carries a series of octets from the start of the IP header of a
        sampled packet.

        With sufficient length, this element also reports octets from



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        the IP payload, subject to [RFC2804]. See the Security
        Considerations section.

        The size of the exported section may be constrained due to
        limitations in the IPFIX protocol.

        If insufficient octets are available for the length specified in
        the Template, the Information Element MUST NOT be padded.
      </paragraph>
    </description>
  </field>

  <field name="ipPayloadPacketSection" dataType="octetArray"
    elementId="314" status="current" group="common">
    <description>
      <paragraph>
        This Information Element, which may have a variable length,
        carries a series of octets from the start of the IP payload of a
        sampled packet.

        The IPv4 payload is that part of the packet which follows the
        IPv4 header and any options, which [RFC0791] refers to as "data"
        or "data octets". e.g., see the examples in [RFC0791] APPENDIX
        A.

        The IPv6 payload is the rest of the packet following the 40
        octet IPv6 header. Note that any extension headers present are
        considered part of the payload. See [RFC2460] for the IPv6
        specification.

        The size of the exported section may be constrained due to
        limitations in the IPFIX protocol.

        If insufficient octets are available for the length specified in
        the Template, the Information Element MUST NOT be padded.
      </paragraph>
    </description>
  </field>

  <field name="dataLinkFrameSection" dataType="octetArray"
    elementId="315" status="current" group="common">
    <description>
      <paragraph>
        This Information Element, which may have a variable length,
        carries the first n octets from the data link frame of a sampled
        packet.

        The data link layer is defined in [ISO_IEC.7498-1_1994].



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        The size of the exported section may be constrained due to
        limitations in the IPFIX protocol.

        If insufficient octets are available for the length specified in
        the Template, the Information Element MUST NOT be padded.
      </paragraph>
    </description>
  </field>

  <field name="mplsLabelStackSection" dataType="octetArray"
    elementId="316" status="current" group="common">
    <description>
      <paragraph>
        This Information Element, which may have a variable length,
        carries the first n octets from the MPLS label stack of a
        sampled packet.

        With sufficient length, this element also reports octets from
        the MPLS payload, subject to [RFC2804]. See the Security
        Considerations section.

        See [RFC3031] for the specification of MPLS packets.

        See [RFC3032] for the specification of the MPLS label stack.

        The size of the exported section may be constrained due to
        limitations in the IPFIX protocol.

        If insufficient octets are available for the length specified in
        the Template, the Information Element MUST NOT be padded.
      </paragraph>
    </description>
  </field>

  <field name="mplsPayloadPacketSection" dataType="octetArray"
    elementId="317" status="current" group="common">
    <description>
      <paragraph>
        This Information Element, which may have a variable length,
        carries the first n octets from the MPLS payload of a sampled
        packet, being data that follows immediately after the MPLS label
        stack.

        See [RFC3031] for the specification of MPLS packets.

        See [RFC3032] for the specification of the MPLS label stack.

        The size of the exported section may be constrained due to



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        limitations in the IPFIX protocol.

        If insufficient octets are available for the length specified in
        the Template, the Information Element MUST NOT be padded.
      </paragraph>
    </description>
  </field>

  <field name="SelectorIdTotalPacketsObserved" dataType="unsigned64"
    dataTypeSemantics="totalCounter" elementId="318" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element specifies the total number of packets
        observed by a Selector, for a specific value of SelectorId.
      </paragraph>
    </description>
    <units>packets</units>
  </field>

  <field name="SelectorIdTotalPacketsSelected" dataType="unsigned64"
    dataTypeSemantics="totalCounter" elementId="319" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element specifies the total number of packets
        selected by a Selector, for a specific value of SelectorId.
      </paragraph>
    </description>
    <units>packets</units>
  </field>

  <field name="fixedError" dataType="float64" elementId="320"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the maximum possible positive
        or negative error interval of the reported value for a given
        Information Element.
      </paragraph>
    </description>
    <units>
      The units of the Information Element for which the error is
      specified.
    </units>
  </field>

  <field name="relativeError" dataType="float64" elementId="321"



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    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the maximum possible positive
        or negative error ratio for a given Information Element.
      </paragraph>
    </description>
  </field>

  <field name="observationTimeSeconds" dataType="dateTimeSeconds"
    elementId="322" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the absolute time in seconds
        of an observation.
      </paragraph>
    </description>
    <units>seconds</units>
  </field>

  <field name="observationTimeMilliseconds"
    dataType="dateTimeMilliseconds" elementId="323" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element specifies the absolute time in
        milliseconds of an observation.
      </paragraph>
    </description>
    <units>milliseconds</units>
  </field>

  <field name="observationTimeMicroseconds"
    dataType="dateTimeMicroseconds" elementId="324" status="current"
    group="common">
    <description>
      <paragraph>
        This Information Element specifies the absolute time in
        microseconds of an observation.
      </paragraph>
    </description>
    <units>microseconds</units>
  </field>

  <field name="observationTimeNanoseconds"
    dataType="dateTimeNanoseconds" elementId="325" status="current"
    group="common">
    <description>



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      <paragraph>
        This Information Element specifies the absolute time in
        nanoseconds of an observation.
      </paragraph>
    </description>
    <units>nanoseconds</units>
  </field>

  <field name="digestHashValue" dataType="unsigned64" elementId="326"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the value from the digest
        hash function.
      </paragraph>
    </description>
  </field>

  <field name="hashIPPayloadOffset" dataType="unsigned64"
    elementId="327" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the IP payload offset used by
        a hash based Selector.
      </paragraph>
    </description>
  </field>

  <field name="hashIPPayloadSize" dataType="unsigned64" elementId="328"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the IP payload size used by a
        hash based Selector.
      </paragraph>
    </description>
  </field>

  <field name="hashOutputRangeMin" dataType="unsigned64" elementId="329"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the value for the beginning
        of a hash function's potential output range.
      </paragraph>
    </description>
  </field>




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  <field name="hashOutputRangeMax" dataType="unsigned64" elementId="330"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the value for the end of a
        hash function's potential output range.
      </paragraph>
    </description>
  </field>

  <field name="hashSelectedRangeMin" dataType="unsigned64"
    elementId="331" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the value for the beginning
        of a hash function's selected range.
      </paragraph>
    </description>
  </field>

  <field name="hashSelectedRangeMax" dataType="unsigned64"
    elementId="332" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the value for the end of a
        hash function's selected range.
      </paragraph>
    </description>
  </field>

  <field name="hashDigestOutput" dataType="boolean" elementId="333"
    status="current" group="common">
    <description>
      <paragraph>
        This Information Element contains a boolean value which is TRUE
        if the output from this hash Selector has been configured to be
        included in the packet report as a packet digest, else FALSE.
      </paragraph>
    </description>
  </field>

  <field name="hashInitialiserValue" dataType="unsigned64"
    elementId="334" status="current" group="common">
    <description>
      <paragraph>
        This Information Element specifies the initialiser value to the
        hash function.
      </paragraph>



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    </description>
  </field>

</fieldDefinitions>















































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Authors' Addresses

   Thomas Dietz
   NEC Europe Ltd.
   NEC Laboratories Europe
   Network Research Division
   Kurfuersten-Anlage 36
   Heidelberg  69115
   Germany

   Phone: +49 6221 4342-128
   Email: dietz@nw.neclab.eu
   URI:   http://www.nw.neclab.eu/


   Falko Dressler
   University of Erlangen-Nuremberg
   Dept. of Computer Sciences
   Martensstr. 3
   Erlangen  91058
   Germany

   Phone: +49 9131 85-27914
   Email: dressler@informatik.uni-erlangen.de
   URI:   http://www7.informatik.uni-erlangen.de/~dressler


   Georg Carle
   University of Tuebingen
   Wilhelm-Schickard-Institute for Computer Science
   Auf der Morgenstelle 10C
   Tuebingen  71076
   Germany

   Phone: +49 7071 29-70505
   Email: carle@informatik.uni-tuebingen.de
   URI:   http://net.informatik.uni-tuebingen.de/~carle/


   Benoit Claise
   Cisco Systems, Inc.
   De Kleetlaan 6a b1
   Degem  1813
   Belgium

   Phone: +32 2 704 5622
   Email: bclaise@cisco.com




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   Paul Aitken
   Cisco Systems, Inc.
   96 Commercial Quay
   Edinburgh  EH6 6LX
   Scotland

   Phone: +44 131 561 3616
   Email: paitken@cisco.com
   URI:   http://www.cisco.com/










































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Full Copyright Statement

   Copyright (C) The IETF Trust (2007).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
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   ietf-ipr@ietf.org.


Acknowledgment

   Funding for the RFC Editor function is provided by the IETF
   Administrative Support Activity (IASA).





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