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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.
Expires: April 26, 2007                                      F. Dressler
                                        University of Erlangen-Nuremberg
                                                                G. Carle
                                                 University of Tuebingen
                                                               B. Claise
                                                               P. Aitken
                                                           Cisco Systems
                                                        October 23, 2006


             Information Model for Packet Sampling Exports
                     <draft-ietf-psamp-info-05.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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   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on April 26, 2007.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This memo defines an information model for the Packet Sampling
   (PSAMP) protocol.  It is used by the PSAMP protocol for encoding



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   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.

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 . . . . . . . . . . . . . . . . . . . . . . . .   4

   2.   PSAMP Documents Overview . . . . . . . . . . . . . . . . . .   4

   3.   Relationship between PSAMP and IPFIX . . . . . . . . . . . .   5

   4.   Terminology  . . . . . . . . . . . . . . . . . . . . . . . .   5
     4.1  General Terminology  . . . . . . . . . . . . . . . . . . .   5
     4.2  PSAMP Terminology  . . . . . . . . . . . . . . . . . . . .   6
     4.3  IPFIX Terminology  . . . . . . . . . . . . . . . . . . . .   7

   5.   Properties of a PSAMP Information Element  . . . . . . . . .   8

   6.   Type Space . . . . . . . . . . . . . . . . . . . . . . . . .   9

   7.   Overloading Information Elements . . . . . . . . . . . . . .   9

   8.   The PSAMP Information Elements . . . . . . . . . . . . . . .   9
     8.1  PSAMP Usage of IPFIX Attributes  . . . . . . . . . . . . .   9
     8.2  Additional PSAMP Information Elements  . . . . . . . . . .  10
       8.2.1  observationPointId . . . . . . . . . . . . . . . . . .  10
       8.2.2  selectionSequenceId  . . . . . . . . . . . . . . . . .  11
       8.2.3  selectorId . . . . . . . . . . . . . . . . . . . . . .  11
       8.2.4  informationElementId . . . . . . . . . . . . . . . . .  11
       8.2.5  selectorAlgorithm  . . . . . . . . . . . . . . . . . .  11
       8.2.6  samplingPacketInterval . . . . . . . . . . . . . . . .  12
       8.2.7  samplingPacketSpace  . . . . . . . . . . . . . . . . .  12
       8.2.8  samplingTimeInterval . . . . . . . . . . . . . . . . .  13
       8.2.9  samplingTimeSpace  . . . . . . . . . . . . . . . . . .  13
       8.2.10   samplingSize . . . . . . . . . . . . . . . . . . . .  13
       8.2.11   samplingPopulation . . . . . . . . . . . . . . . . .  13
       8.2.12   samplingProbability  . . . . . . . . . . . . . . . .  14
       8.2.13   dataLinkFrameSize  . . . . . . . . . . . . . . . . .  14
       8.2.14   ipHeaderPacketSection  . . . . . . . . . . . . . . .  14
       8.2.15   ipPayloadPacketSection . . . . . . . . . . . . . . .  15
       8.2.16   dataLinkFrameSection . . . . . . . . . . . . . . . .  15



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       8.2.17   mplsLabelStackSection  . . . . . . . . . . . . . . .  16
       8.2.18   mplsPayloadPacketSection . . . . . . . . . . . . . .  16
       8.2.19   packetsObserved  . . . . . . . . . . . . . . . . . .  17
       8.2.20   packetsSelected  . . . . . . . . . . . . . . . . . .  17
       8.2.21   fixedError . . . . . . . . . . . . . . . . . . . . .  17
       8.2.22   relativeError  . . . . . . . . . . . . . . . . . . .  17
       8.2.23   observationTimeSeconds . . . . . . . . . . . . . . .  17
       8.2.24   observationTimeMilliseconds  . . . . . . . . . . . .  18
       8.2.25   observationTimeMicroseconds  . . . . . . . . . . . .  18
       8.2.26   observationTimeNanoseconds . . . . . . . . . . . . .  18
       8.2.27   digestHashValue  . . . . . . . . . . . . . . . . . .  18
       8.2.28   hashIPPayloadOffset  . . . . . . . . . . . . . . . .  18
       8.2.29   hashIPPayloadSize  . . . . . . . . . . . . . . . . .  19
       8.2.30   hashOutputRangeMin . . . . . . . . . . . . . . . . .  19
       8.2.31   hashOutputRangeMax . . . . . . . . . . . . . . . . .  19
       8.2.32   hashSelectedRangeMin . . . . . . . . . . . . . . . .  19
       8.2.33   hashSelectedRangeMax . . . . . . . . . . . . . . . .  19
       8.2.34   hashDigestOutput . . . . . . . . . . . . . . . . . .  20
       8.2.35   hashInitialiserValue . . . . . . . . . . . . . . . .  20

   9.   Security Considerations  . . . . . . . . . . . . . . . . . .  20

   10.  IANA Considerations  . . . . . . . . . . . . . . . . . . . .  20

   11.  References . . . . . . . . . . . . . . . . . . . . . . . . .  21
     11.1   Normative References . . . . . . . . . . . . . . . . . .  21
     11.2   Informative References . . . . . . . . . . . . . . . . .  22

        Authors' Addresses . . . . . . . . . . . . . . . . . . . . .  23

   A.   Formal Specification of PSAMP Information Elements . . . . .  24

        Intellectual Property and Copyright Statements . . . . . . .  38


















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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 of such
   sampled packet data 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] describes 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.

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.




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   [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.

   [I-D.ietf-psamp-info]: "Information Model for Packet Sampling
   Exports" (this document), defines an information and data model for
   PSAMP.

3.  Relationship between PSAMP and IPFIX

   As described in the PSAMP protocol draft [I-D.ietf-psamp-protocol] a
   PSAMP data record 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 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 data 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].

4.  Terminology

4.1  General Terminology

   o  IETF:  The Internet Engineering Task Force

      http://www.ietf.org

   o  IPFIX: The IETF IP Flow Information eXport working group

      http://www.ietf.org/html.charters/ipfix-charter.html

   o  PSAMP: The IETF Packet SAMPling working group

      http://www.ietf.org/html.charters/psamp-charter.html






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   o  IANA:  Internet Assigned Numbers Authority

      http://www.iana.org

   o  RFC:   Requests for Comments

      http://www.rfc-editor.org

   o  ISO:   International Organisation for Stadardisation

      http://www.iso.org

   o  IEC:   International Electrotechnical Commission

      http://www.iec.ch

4.2  PSAMP Terminology

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

   o  Observed Packet Stream

      The Observed Packet Stream is the set of all packets observed at
      the Observation Point.

   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  Packet Stream

      A packet stream denotes a subset of the Observed Packet Stream
      that flows past some specified point within the Selection Process.

   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.

   o  Selector

      A Selector defines the action of a Selection Process on a single
      packet of its input.





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   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.

4.3  IPFIX 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.

   o  Observation Point

      An Observation Point is a location in the network where packets
      can be observed.

   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  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  Flow Record

      A Flow Record contains information about a specific Flow that was
      observed at an Observation Point.





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   o  Metering Process

      The Metering Process generates Flow Records.

   o  Exporting Process

      The Exporting Process sends Flow Records to one or more Collecting
      Processes.  The Flow Records are generated by one or more Metering
      Processes.

   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.

   o  Collecting Process

      A Collecting Process receives Flow Records from one or more
      Exporting Processes.

   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.

   o  Information Element

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

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 to define
   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.

7.  Overloading Information Elements

   Information Elements won't be overloaded with multiple meanings or
   re-used for multiple purposes.  Different Information Elements will
   be allocated for each requirement.

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

   Although the prescence 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.

8.  The PSAMP Information Elements

   This section describes the Information Elements used by the PSAMP
   exporting functions.

   Each Information Element defined in section 8.2 below is allocated a
   unique identifier in accordance with section 4 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 described by the IPFIX information model
   [I-D.ietf-ipfix-info] are used by the PSAMP export functions 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

   Some Information Elements defined by the IPFIX information model are
   not needed by the PSAMP protocol.

   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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   o  300 - observationPointId
   o  301 - selectionSequenceId
   o  302 - selectorId
   o  303 - informationElementId
   o  304 - selectorAlgorithm
   o  305 - samplingPacketInterval
   o  306 - samplingPacketSpace
   o  307 - samplingTimeInterval
   o  308 - samplingTimeSpace
   o  309 - samplingSize
   o  310 - samplingPopulation
   o  311 - samplingProbability
   o  312 - dataLinkFrameSize
   o  313 - ipHeaderPacketSection
   o  314 - ipPayloadPacketSection
   o  315 - dataLinkFrameSection
   o  316 - mplsLabelStackSection
   o  317 - mplsPayloadPacketSection
   o  318 - packetsObserved
   o  319 - packetsSelected
   o  320 - fixedError
   o  321 - relativeError
   o  322 - observationTimeSeconds
   o  323 - observationTimeMilliseconds
   o  324 - observationTimeMicroseconds
   o  325 - observationTimeNanoseconds
   o  326 - digestHashValue
   o  327 - hashIPPayloadOffset
   o  328 - hashIPPayloadSize
   o  329 - hashOutputRangeMin
   o  330 - hashOutputRangeMax
   o  331 - hashSelectedRangeMin
   o  332 - hashSelectedRangeMax
   o  333 - hashDigestOutput
   o  334 - hashInitialiserValue

8.2  Additional PSAMP Information Elements

8.2.1  observationPointId

   Description:
      ID of the Observation Point.  Unique in the Observation Domain.
   Abstract Data Type: unsigned64
   ElementId: 300







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   Status: current

8.2.2  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,
      describing the Observation Point and the sequence of Selectors
      through which the packets are selected.
   Abstract Data Type: unsigned64
   ElementId: 301
   Status: current

8.2.3  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

8.2.4  informationElementId

   Description:
      Contains the ID of another Information Element.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 303
   Status: current

8.2.5  selectorAlgorithm

   Description:
      Specifies the Selector algorithm (e.g., filter, sampler, hash)
      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





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      *  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.

      In future, 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

8.2.6  samplingPacketInterval

   Description:
      Number of packets that are consecutively sampled.  For example a
      value of 100 means that 100 contiguous packets are sampled.

      This information element is used to describe the configuration of
      a systematic count-based sampling Selector.
   Abstract Data Type: unsigned32
   ElementId: 305
   Status: current
   Units: packets

8.2.7  samplingPacketSpace

   Description:
      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.

      This information element is used to describe the configuration of
      a systematic count-based sampling Selector.
   Abstract Data Type: unsigned32
   ElementId: 306
   Status: current







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   Units: packets

8.2.8  samplingTimeInterval

   Description:
      Time interval in microseconds in which all arriving packets are
      sampled.

      This information element is used to describe the configuration of
      a systematic time-based sampling Selector.
   Abstract Data Type: dateTimeMicroseconds
   ElementId: 307
   Status: current
   Units: microseconds

8.2.9  samplingTimeSpace

   Description:
      The time interval in microseconds between two
      "samplingTimeInterval"s.  A value of 100 means that the next
      interval starts after 100 microseconds (in which no packets are
      sampled) when the current "samplingTimeInterval" is over.

      This information element is used to describe the configuration of
      a systematic time-based sampling Selector.
   Abstract Data Type: dateTimeMicroseconds
   ElementId: 308
   Status: current
   Units: microseconds

8.2.10  samplingSize

   Description:
      The number of elements taken from the parent Population for random
      sampling algorithms.

      This information element is used to describe the configuration of
      a random n-out-of-N sampling Selector.
   Abstract Data Type: unsigned32
   ElementId: 309
   Status: current
   Units: packets

8.2.11  samplingPopulation







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   Description:
      The number of elements in the parent Population for random
      sampling algorithms.

      This information element is used to describe the configuration of
      a random n-out-of-N sampling Selector.
   Abstract Data Type: unsigned32
   ElementId: 310
   Status: current
   Units: packets

8.2.12  samplingProbability

   Description:
      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.

      This information element is used to describe the configuration of
      a uniform probabilistic sampling Selector.
   Abstract Data Type: float64
   ElementId: 311
   Status: current

8.2.13  dataLinkFrameSize

   Description:
      The size of the data link frame.

      The data link layer is defined in [ISO/IEC.7498-1:1994].
   Abstract Data Type: unsigned32
   ElementId: 312
   Status: current

8.2.14  ipHeaderPacketSection

   Description:
      This information element 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] and the PSAMP WG charter.  See
      the Security Considerations section.








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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.
   Abstract Data Type: variable length octetArray
   ElementId: 313
   Status: current

8.2.15  ipPayloadPacketSection

   Description:
      This information element 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.
   Abstract Data Type: variable length octetArray
   ElementId: 314
   Status: current

8.2.16  dataLinkFrameSection

   Description:
      This information element 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.








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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: variable length octetArray
   ElementId: 315
   Status: current

8.2.17  mplsLabelStackSection

   Description:
      This information element 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] and the PSAMP WG charter.  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.
   Abstract Data Type: variable length octetArray
   ElementId: 316
   Status: current

8.2.18  mplsPayloadPacketSection

   Description:
      This information element 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: variable length octetArray







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   ElementId: 317
   Status: current

8.2.19  packetsObserved

   Description:
      Number of packets observed by a Selector.
   Abstract Data Type: unsigned64
   ElementId: 318
   Status: current
   Units: packets

8.2.20  packetsSelected

   Description:
      Number of packets selected by a Selector.
   Abstract Data Type: unsigned64
   ElementId: 319
   Status: current
   Units: packets

8.2.21  fixedError

   Description:
      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.

8.2.22  relativeError

   Description:
      Specifies the maximum possible positive or negative error ratio
      for a given Information Element.
   Abstract Data Type: float64
   ElementId: 321
   Status: current

8.2.23  observationTimeSeconds

   Description:







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      The absolute time of an observation.
   Abstract Data Type: dateTimeSeconds
   ElementId: 322
   Status: current
   Units: seconds

8.2.24  observationTimeMilliseconds

   Description:
      The absolute time of an observation.
   Abstract Data Type: dateTimeMilliseconds
   ElementId: 323
   Status: current
   Units: milliseconds

8.2.25  observationTimeMicroseconds

   Description:
      The absolute time of an observation.
   Abstract Data Type: dateTimeMicroseconds
   ElementId: 324
   Status: current
   Units: microseconds

8.2.26  observationTimeNanoseconds

   Description:
      The absolute time of an observation.
   Abstract Data Type: dateTimeNanoseconds
   ElementId: 325
   Status: current
   Units: nanoseconds

8.2.27  digestHashValue

   Description:
      The value from the digest hash function.
   Abstract Data Type: unsigned64
   ElementId: 326
   Status: current

8.2.28  hashIPPayloadOffset

   Description:







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      The IP payload offset used by a hash based Selector.
   Abstract Data Type: unsigned64
   ElementId: 327
   Status: current

8.2.29  hashIPPayloadSize

   Description:
      The IP payload size used by a hash based Selector.
   Abstract Data Type: unsigned64
   ElementId: 328
   Status: current

8.2.30  hashOutputRangeMin

   Description:
      A value for the beginning of a hash function's potential output
      range.
   Abstract Data Type: unsigned64
   ElementId: 329
   Status: current

8.2.31  hashOutputRangeMax

   Description:
      A value for the end of a hash function's potential output range.
   Abstract Data Type: unsigned64
   ElementId: 330
   Status: current

8.2.32  hashSelectedRangeMin

   Description:
      A value for the beginning of a hash function's selected range.
   Abstract Data Type: unsigned64
   ElementId: 331
   Status: current

8.2.33  hashSelectedRangeMax

   Description:
      A value for the end of a hash function's selected range.
   Abstract Data Type: unsigned64
   ElementId: 332







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   Status: current

8.2.34  hashDigestOutput

   Description:
      A boolean value, 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

8.2.35  hashInitialiserValue

   Description:
      The initialiser value to the hash function.
   Abstract Data Type: unsigned64
   ElementId: 334
   Status: current

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] and the PSAMP WG charter.

   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 IPFIX
   protocol document [I-D.ietf-ipfix-protocol].

10.  IANA Considerations

   This document defines 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



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   the value 300, 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].

   In future the selectorAlgorithm registry 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.

11.  References

11.1  Normative References

   [I-D.ietf-psamp-sample-tech]
              Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F.
              Raspall, "Sampling and Filtering Techniques for IP Packet
              Selection", draft-ietf-psamp-sample-tech-07 (work in
              progress), July 2005.

   [I-D.ietf-psamp-protocol]
              Claise, B., Quittek, J., and A. Johnson, "Packet Sampling
              (PSAMP) Protocol Specifications",
              draft-ietf-psamp-protocol-03 (work in progress),
              December 2005.

   [I-D.ietf-ipfix-info]
              Quittek, J., Bryant, S., Claise, B., and J. Meyer,
              "Information Model for IP Flow Information Export",
              draft-ietf-ipfix-info-11 (work in progress),
              September 2005.

   [I-D.ietf-ipfix-protocol]
              Claise, B., "Specification of the IPFIX Protocol for the
              Exchange of IP Traffic Flow Information",
              draft-ietf-ipfix-protocol-23 (work in progress),
              October 2006.

   [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.



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   [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", RFC 3917,
              October 2004.

   [I-D.ietf-ipfix-architecture]
              Sadasivan, G., Brownlee, N., Claise, B., and J. Quittek,
              "Architecture for IP Flow Information Export",
              draft-ietf-ipfix-architecture-09 (work in progress),
              August 2005.

   [I-D.ietf-psamp-framework]
              Duffield, N., Chiou, D., Claise, B., Greenberg, A.,
              Grossglauser, M., Marimuthu, P., Rexford, J., and G.
              Sadasivan, "A Framework for Packet Selection and
              Reporting", draft-ietf-psamp-framework-10 (work in
              progress), January 2005.

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

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

   [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
              Information Models and Data Models", RFC 3444,
              January 2003.

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

   [RFC3470]  Hollenbeck, S., Rose, M., and L. Masinter, "Guidelines for
              the Use of Extensible Markup Language (XML) within IETF
              Protocols", BCP 70, RFC 3470, January 2003.



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


Authors' Addresses

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

   Phone: +49 6221 90511-28
   Email: dietz@netlab.nec.de
   URI:   http://www.netlab.nec.de/


   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/











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

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


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

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

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



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   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="http://www.ietf.org/ipfix"-->
     <field name="observationPointId" dataType="unsigned64"
            fieldId="300" status="current" group="common">
       <description>
         <paragraph>
           ID of the Observation Point.
           Unique in the Observation Domain.
         </paragraph>
       </description>
     </field>

     <field name="selectionSequenceId" dataType="unsigned64"
            fieldId="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, describing the Observation Point and the
           sequence of Selectors through which the packets are selected.
         </paragraph>
       </description>
     </field>

     <field name="selectorId" dataType="unsigned16"
            dataTypeSemantics="identifier"
            fieldId="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"
            fieldId="303" status="current" group="common">



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       <description>
         <paragraph>
           Contains the ID of another Information Element.
         </paragraph>
       </description>
     </field>

     <field name="selectorAlgorithm" dataType="unsigned16"
            dataTypeSemantics="identifier"
            fieldId="304" status="current" group="common">
       <description>
         <paragraph>
           Specifies the Selector algorithm (e.g., filter, sampler,
           hash) that was used on a packet.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           The following Selector algorithms are currently defined:
         </paragraph>

         <vspace blankLines="1" />

         <itemlist>
           <item>1 Systematic count-based sampling</item>
           <item>2 Systematic time-based sampling</item>
           <item>3 Random n-out-of-N sampling</item>
           <item>4 Uniform probabilistic sampling</item>
           <item>5 Property match filtering</item>
           <item>6 Hash based filtering using BOB</item>
           <item>7 Hash based filtering using IPSX</item>
           <item>8 Hash based filtering using CRC</item>
         </itemlist>

         <vspace blankLines="1" />

         <paragraph>
           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.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           In future, this list will be maintained by IANA.



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           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"
            fieldId="305" status="current" group="common">
       <description>
         <paragraph>
           Number of packets that are consecutively sampled.
           For example a value of 100 means that 100 contiguous
           packets are sampled.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           This information element is used to describe the
           configuration of a systematic count-based sampling Selector.
         </paragraph>
       </description>
       <units>packets</units>
     </field>

     <field name="samplingPacketSpace" dataType="unsigned32"
            fieldId="306" status="current" group="common">
       <description>
         <paragraph>
           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.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           This information element is used to describe the
           configuration of a systematic count-based sampling Selector.
         </paragraph>
       </description>
       <units>packets</units>
     </field>

     <field name="samplingTimeInterval" dataType="dateTimeMicroseconds"
            fieldId="307" status="current" group="common">



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       <description>
         <paragraph>
           Time interval in microseconds in which all arriving
           packets are sampled.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           This information element is used to describe the
           configuration of a systematic time-based sampling Selector.
         </paragraph>
       </description>
       <units>microseconds</units>
     </field>

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

         <vspace blankLines="1" />

         <paragraph>
           This information element is used to describe the
           configuration of a systematic time-based sampling Selector.
         </paragraph>
       </description>
       <units>microseconds</units>
     </field>

     <field name="samplingSize" dataType="unsigned32"
            fieldId="309" status="current" group="common">
       <description>
         <paragraph>
           The number of elements taken from the parent
           Population for random sampling algorithms.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>



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           This information element is 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"
            fieldId="310" status="current" group="common">
       <description>
         <paragraph>
           The number of elements in the parent Population
           for random sampling algorithms.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           This information element is 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"
            fieldId="311" status="current" group="common">
       <description>
         <paragraph>
           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.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           This information element is used to describe the
           configuration of a uniform probabilistic sampling Selector.
         </paragraph>
       </description>
     </field>

     <field name="dataLinkFrameSize"
            dataType="unsigned32"
            fieldId="312" status="current" group="common">



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       <description>
         <paragraph>
           The size of the data link frame.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           The data link layer is defined in
           <xref target="ISO/IEC.7498-1:1994"/>.
         </paragraph>
       </description>
     </field>

     <field name="ipHeaderPacketSection"
            dataType="variable length octetArray"
            fieldId="313" status="current" group="common">
       <description>
         <paragraph>
           This information element carries a series of octets
           from the start of the IP header of a sampled packet.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           With sufficient length, this element also reports
           octets from the IP payload, subject to [RFC2804] and
           the PSAMP WG charter. See the Security Considerations
           section.
         </paragraph>

         <vspace blankLines="1" />

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

         <vspace blankLines="1" />

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




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     <field name="ipPayloadPacketSection"
            dataType="variable length octetArray"
            fieldId="314" status="current" group="common">
       <description>
         <paragraph>
           This information element carries a series of octets
           from the start of the IP payload of a sampled packet.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           The IPv4 payload is that part of the packet which follows the
           IPv4 header and any options, which <xref target="RFC0791"/>
           refers to as "data" or "data octets".
           e.g., see the examples in <xref target="RFC0791"/>
           APPENDIX A.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           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 <xref target="RFC2460"/> for the IPv6 specification.
         </paragraph>

         <vspace blankLines="1" />

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

         <vspace blankLines="1" />

         <paragraph>
           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="variable length octetArray"
            fieldId="315" status="current" group="common">
       <description>



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         <paragraph>
           This information element carries the first n octets
           from the data link frame of a sampled packet.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           The data link layer is defined in
           <xref target="ISO/IEC.7498-1:1994"/>.
         </paragraph>

         <vspace blankLines="1" />

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

         <vspace blankLines="1" />

         <paragraph>
           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="variable length octetArray"
            fieldId="316" status="current" group="common">
       <description>
         <paragraph>
           This information element carries the first n octets
           from the MPLS label stack of a sampled packet.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           With sufficient length, this element also reports
           octets from the MPLS payload, subject to [RFC2804] and
           the PSAMP WG charter. See the Security Considerations
           section.
         </paragraph>

         <vspace blankLines="1" />




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         <paragraph>
           See <xref target="RFC3031"/>
           for the specification of MPLS packets.
           <vspace blankLines="0" />
           See <xref target="RFC3032"/>
           for the specification of the MPLS label stack.
         </paragraph>

         <vspace blankLines="1" />

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

         <vspace blankLines="1" />

         <paragraph>
           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="variable length octetArray"
            fieldId="317" status="current" group="common">
       <description>
         <paragraph>
           This information element carries the first n octets
           from the MPLS payload of a sampled packet, being data
           that follows immediately after the MPLS label stack.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           See <xref target="RFC3031"/>
           for the specification of MPLS packets.
           <vspace blankLines="0" />
           See <xref target="RFC3032"/>
           for the specification of the MPLS label stack.
         </paragraph>

         <vspace blankLines="1" />

         <paragraph>
           The size of the exported section may be constrained



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           due to limitations in the IPFIX protocol.
         </paragraph>

         <vspace blankLines="1" />

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

     <field name="packetsObserved" dataType="unsigned64"
            fieldId="318" status="current" group="common">
       <description>
         <paragraph>
           Number of packets observed by a Selector.
         </paragraph>
       </description>
       <units>packets</units>
     </field>

     <field name="packetsSelected" dataType="unsigned64"
            fieldId="319" status="current" group="common">
       <description>
         <paragraph>
           Number of packets selected by a Selector.
         </paragraph>
       </description>
       <units>packets</units>
     </field>

     <field name="fixedError" dataType="float64"
            fieldId="320" status="current" group="common">
       <description>
         <paragraph>
            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"



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            fieldId="321" status="current" group="common">
       <description>
         <paragraph>
           Specifies the maximum possible positive or negative
           error ratio for a given Information Element.
         </paragraph>
       </description>
     </field>

     <field name="observationTimeSeconds"
            dataType="dateTimeSeconds"
            fieldId="322" status="current" group="common">
       <description>
         <paragraph>
           The absolute time of an observation.
         </paragraph>
       </description>
       <units>seconds</units>
     </field>

     <field name="observationTimeMilliseconds"
            dataType="dateTimeMilliseconds"
            fieldId="323" status="current" group="common">
       <description>
         <paragraph>
           The absolute time of an observation.
         </paragraph>
       </description>
       <units>milliseconds</units>
     </field>

     <field name="observationTimeMicroseconds"
            dataType="dateTimeMicroseconds"
            fieldId="324" status="current" group="common">
       <description>
         <paragraph>
           The absolute time of an observation.
         </paragraph>
       </description>
       <units>microseconds</units>
     </field>

     <field name="observationTimeNanoseconds"
            dataType="dateTimeNanoseconds"
            fieldId="325" status="current" group="common">
       <description>
         <paragraph>
           The absolute time of an observation.



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         </paragraph>
       </description>
       <units>nanoseconds</units>
     </field>

     <field name="digestHashValue" dataType="unsigned64"
            fieldId="326" status="current" group="common">
       <description>
         <paragraph>
           The value from the digest hash function.
         </paragraph>
       </description>
     </field>

     <field name="hashIPPayloadOffset" dataType="unsigned64"
            fieldId="327" status="current" group="common">
       <description>
         <paragraph>
           The IP payload offset used by a hash based Selector.
         </paragraph>
       </description>
     </field>

     <field name="hashIPPayloadSize" dataType="unsigned64"
            fieldId="328" status="current" group="common">
       <description>
         <paragraph>
           The IP payload size used by a hash based Selector.
         </paragraph>
       </description>
     </field>

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

     <field name="hashOutputRangeMax" dataType="unsigned64"
            fieldId="330" status="current" group="common">
       <description>
         <paragraph>
           A value for the end of a hash function's
           potential output range.



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

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

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

     <field name="hashDigestOutput" dataType="boolean"
            fieldId="333" status="current" group="common">
       <description>
         <paragraph>
           A boolean value, 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"
            fieldId="334" status="current" group="common">
       <description>
         <paragraph>
           The initialiser value to the hash function.
         </paragraph>
       </description>
     </field>

   </fieldDefinitions>






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