[Text version]

Network Working Group Request for Comments: 5102 Category: Standards Track

J. Quittek NEC S. Bryant B. Claise P. Aitken Cisco Systems, Inc. J. Meyer PayPal January 2008

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Abstract

This memo defines an information model for the IP Flow Information eXport (IPFIX) protocol. It is used by the IPFIX protocol for encoding measured traffic information and information related to the traffic Observation Point, the traffic Metering Process, and the Exporting Process. Although developed for the IPFIX protocol, the model is defined in an open way that easily allows using it in other protocols, interfaces, and applications.

Table of Contents

   1. Introduction ....................................................6
   2. Properties of IPFIX Protocol Information Elements ...............7
      2.1. Information Elements Specification Template ................7
      2.2. Scope of Information Elements ..............................9
      2.3. Naming Conventions for Information Elements ................9
   3. Type Space .....................................................10
      3.1. Abstract Data Types .......................................10
           3.1.1. unsigned8 ..........................................10
           3.1.2. unsigned16 .........................................11
           3.1.3. unsigned32 .........................................11
           3.1.4. unsigned64 .........................................11
           3.1.5. signed8 ............................................11
           3.1.6. signed16 ...........................................11
           3.1.7. signed32 ...........................................11
           3.1.8. signed64 ...........................................11

           3.1.9. float32 ............................................11
           3.1.10. float64 ...........................................11
           3.1.11. boolean ...........................................12
           3.1.12. macAddress ........................................12
           3.1.13. octetArray ........................................12
           3.1.14. string ............................................12
           3.1.15. dateTimeSeconds ...................................12
           3.1.16. dateTimeMilliseconds ..............................12
           3.1.17. dateTimeMicroseconds ..............................12
           3.1.18. dateTimeNanoseconds ...............................13
           3.1.19. ipv4Address .......................................13
           3.1.20. ipv6Address .......................................13
      3.2. Data Type Semantics .......................................13
           3.2.1. quantity ...........................................13
           3.2.2. totalCounter .......................................13
           3.2.3. deltaCounter .......................................14
           3.2.4. identifier .........................................14
           3.2.5. flags ..............................................14
   4. Information Element Identifiers ................................14
   5. Information Elements ...........................................18
      5.1. Identifiers ...............................................19
           5.1.1. lineCardId .........................................20
           5.1.2. portId .............................................20
           5.1.3. ingressInterface ...................................20
           5.1.4. egressInterface ....................................21
           5.1.5. meteringProcessId ..................................21
           5.1.6. exportingProcessId .................................21
           5.1.7. flowId .............................................22
           5.1.8. templateId .........................................22
           5.1.9. observationDomainId ................................22
           5.1.10. observationPointId ................................23
           5.1.11. commonPropertiesId ................................23
      5.2. Metering and Exporting Process Configuration ..............23
           5.2.1. exporterIPv4Address ................................24
           5.2.2. exporterIPv6Address ................................24
           5.2.3. exporterTransportPort ..............................24
           5.2.4. collectorIPv4Address ...............................25
           5.2.5. collectorIPv6Address ...............................25
           5.2.6. exportInterface ....................................25
           5.2.7. exportProtocolVersion ..............................26
           5.2.8. exportTransportProtocol ............................26
           5.2.9. collectorTransportPort .............................27
           5.2.10. flowKeyIndicator ..................................27
      5.3. Metering and Exporting Process Statistics .................28
           5.3.1. exportedMessageTotalCount ..........................28
           5.3.2. exportedOctetTotalCount ............................28
           5.3.3. exportedFlowRecordTotalCount .......................29
           5.3.4. observedFlowTotalCount .............................29

           5.3.5. ignoredPacketTotalCount ............................29
           5.3.6. ignoredOctetTotalCount .............................30
           5.3.7. notSentFlowTotalCount ..............................30
           5.3.8. notSentPacketTotalCount ............................30
           5.3.9. notSentOctetTotalCount .............................31
      5.4. IP Header Fields ..........................................31
           5.4.1. ipVersion ..........................................31
           5.4.2. sourceIPv4Address ..................................32
           5.4.3. sourceIPv6Address ..................................32
           5.4.4. sourceIPv4PrefixLength .............................32
           5.4.5. sourceIPv6PrefixLength .............................33
           5.4.6. sourceIPv4Prefix ...................................33
           5.4.7. sourceIPv6Prefix ...................................33
           5.4.8. destinationIPv4Address .............................33
           5.4.9. destinationIPv6Address .............................34
           5.4.10. destinationIPv4PrefixLength .......................34
           5.4.11. destinationIPv6PrefixLength .......................34
           5.4.12. destinationIPv4Prefix .............................34
           5.4.13. destinationIPv6Prefix .............................35
           5.4.14. ipTTL .............................................35
           5.4.15. protocolIdentifier ................................35
           5.4.16. nextHeaderIPv6 ....................................36
           5.4.17. ipDiffServCodePoint ...............................36
           5.4.18. ipPrecedence ......................................36
           5.4.19. ipClassOfService ..................................37
           5.4.20. postIpClassOfService ..............................37
           5.4.21. flowLabelIPv6 .....................................38
           5.4.22. isMulticast .......................................38
           5.4.23. fragmentIdentification ............................39
           5.4.24. fragmentOffset ....................................39
           5.4.25. fragmentFlags .....................................39
           5.4.26. ipHeaderLength ....................................40
           5.4.27. ipv4IHL ...........................................40
           5.4.28. totalLengthIPv4 ...................................41
           5.4.29. ipTotalLength .....................................41
           5.4.30. payloadLengthIPv6 .................................41
      5.5. Transport Header Fields ...................................42
           5.5.1. sourceTransportPort ................................42
           5.5.2. destinationTransportPort ...........................42
           5.5.3. udpSourcePort ......................................43
           5.5.4. udpDestinationPort .................................43
           5.5.5. udpMessageLength ...................................43
           5.5.6. tcpSourcePort ......................................44
           5.5.7. tcpDestinationPort .................................44
           5.5.8. tcpSequenceNumber ..................................44
           5.5.9. tcpAcknowledgementNumber ...........................44
           5.5.10. tcpWindowSize .....................................45
           5.5.11. tcpWindowScale ....................................45

           5.5.12. tcpUrgentPointer ..................................45
           5.5.13. tcpHeaderLength ...................................45
           5.5.14. icmpTypeCodeIPv4 ..................................46
           5.5.15. icmpTypeIPv4 ......................................46
           5.5.16. icmpCodeIPv4 ......................................46
           5.5.17. icmpTypeCodeIPv6 ..................................46
           5.5.18. icmpTypeIPv6 ......................................47
           5.5.19. icmpCodeIPv6 ......................................47
           5.5.20. igmpType ..........................................47
      5.6. Sub-IP Header Fields ......................................48
           5.6.1. sourceMacAddress ...................................48
           5.6.2. postSourceMacAddress ...............................48
           5.6.3. vlanId .............................................49
           5.6.4. postVlanId .........................................49
           5.6.5. destinationMacAddress ..............................49
           5.6.6. postDestinationMacAddress ..........................49
           5.6.7. wlanChannelId ......................................50
           5.6.8. wlanSSID ...........................................50
           5.6.9. mplsTopLabelTTL ....................................50
           5.6.10. mplsTopLabelExp ...................................51
           5.6.11. postMplsTopLabelExp ...............................51
           5.6.12. mplsLabelStackDepth ...............................51
           5.6.13. mplsLabelStackLength ..............................52
           5.6.14. mplsPayloadLength .................................52
           5.6.15. mplsTopLabelStackSection ..........................52
           5.6.16. mplsLabelStackSection2 ............................53
           5.6.17. mplsLabelStackSection3 ............................53
           5.6.18. mplsLabelStackSection4 ............................53
           5.6.19. mplsLabelStackSection5 ............................54
           5.6.20. mplsLabelStackSection6 ............................54
           5.6.21. mplsLabelStackSection7 ............................54
           5.6.22. mplsLabelStackSection8 ............................55
           5.6.23. mplsLabelStackSection9 ............................55
           5.6.24. mplsLabelStackSection10 ...........................55
      5.7. Derived Packet Properties .................................56
           5.7.1. ipPayloadLength ....................................56
           5.7.2. ipNextHopIPv4Address ...............................56
           5.7.3. ipNextHopIPv6Address ...............................57
           5.7.4. bgpSourceAsNumber ..................................57
           5.7.5. bgpDestinationAsNumber .............................57
           5.7.6. bgpNextAdjacentAsNumber ............................57
           5.7.7. bgpPrevAdjacentAsNumber ............................58
           5.7.8. bgpNextHopIPv4Address ..............................58
           5.7.9. bgpNextHopIPv6Address ..............................58
           5.7.10. mplsTopLabelType ..................................59
           5.7.11. mplsTopLabelIPv4Address ...........................59
           5.7.12. mplsTopLabelIPv6Address ...........................60
           5.7.13. mplsVpnRouteDistinguisher .........................60

      5.8. Min/Max Flow Properties ...................................61
           5.8.1. minimumIpTotalLength ...............................61
           5.8.2. maximumIpTotalLength ...............................61
           5.8.3. minimumTTL .........................................61
           5.8.4. maximumTTL .........................................62
           5.8.5. ipv4Options ........................................62
           5.8.6. ipv6ExtensionHeaders ...............................64
           5.8.7. tcpControlBits .....................................65
           5.8.8. tcpOptions .........................................66
      5.9. Flow Timestamps ...........................................67
           5.9.1. flowStartSeconds ...................................67
           5.9.2. flowEndSeconds .....................................68
           5.9.3. flowStartMilliseconds ..............................68
           5.9.4. flowEndMilliseconds ................................68
           5.9.5. flowStartMicroseconds ..............................68
           5.9.6. flowEndMicroseconds ................................68
           5.9.7. flowStartNanoseconds ...............................69
           5.9.8. flowEndNanoseconds .................................69
           5.9.9. flowStartDeltaMicroseconds .........................69
           5.9.10. flowEndDeltaMicroseconds ..........................69
           5.9.11. systemInitTimeMilliseconds ........................70
           5.9.12. flowStartSysUpTime ................................70
           5.9.13. flowEndSysUpTime ..................................70
      5.10. Per-Flow Counters ........................................70
           5.10.1. octetDeltaCount ...................................71
           5.10.2. postOctetDeltaCount ...............................71
           5.10.3. octetDeltaSumOfSquares ............................72
           5.10.4. octetTotalCount ...................................72
           5.10.5. postOctetTotalCount ...............................72
           5.10.6. octetTotalSumOfSquares ............................72
           5.10.7. packetDeltaCount ..................................73
           5.10.8. postPacketDeltaCount ..............................73
           5.10.9. packetTotalCount ..................................73
           5.10.10. postPacketTotalCount .............................74
           5.10.11. droppedOctetDeltaCount ...........................74
           5.10.12. droppedPacketDeltaCount ..........................74
           5.10.13. droppedOctetTotalCount ...........................74
           5.10.14. droppedPacketTotalCount ..........................75
           5.10.15. postMCastPacketDeltaCount ........................75
           5.10.16. postMCastOctetDeltaCount .........................75
           5.10.17. postMCastPacketTotalCount ........................76
           5.10.18. postMCastOctetTotalCount .........................76
           5.10.19. tcpSynTotalCount .................................76
           5.10.20. tcpFinTotalCount .................................77
           5.10.21. tcpRstTotalCount .................................77
           5.10.22. tcpPshTotalCount .................................77
           5.10.23. tcpAckTotalCount .................................78
           5.10.24. tcpUrgTotalCount .................................78

      5.11. Miscellaneous Flow Properties ............................78
           5.11.1. flowActiveTimeout .................................79
           5.11.2. flowIdleTimeout ...................................79
           5.11.3. flowEndReason .....................................79
           5.11.4. flowDurationMilliseconds ..........................80
           5.11.5. flowDurationMicroseconds ..........................80
           5.11.6. flowDirection .....................................80
      5.12. Padding ..................................................80
           5.12.1. paddingOctets .....................................81
   6. Extending the Information Model ................................81
   7. IANA Considerations ............................................82
      7.1. IPFIX Information Elements ................................82
      7.2. MPLS Label Type Identifier ................................82
      7.3. XML Namespace and Schema ..................................83
   8. Security Considerations ........................................83
   9. Acknowledgements ...............................................84
   10. References ....................................................84
      10.1. Normative References .....................................84
      10.2. Informative References ...................................84
   Appendix A. XML Specification of IPFIX Information Elements .......88
   Appendix B. XML Specification of Abstract Data Types .............157

1. Introduction

The IP Flow Information eXport (IPFIX) protocol serves for transmitting information related to measured IP traffic over the Internet. The protocol specification in [RFC5101] defines how Information Elements are transmitted. For Information Elements, it specifies the encoding of a set of basic data types. However, the list of Information Elements that can be transmitted by the protocol, such as Flow attributes (source IP address, number of packets, etc.) and information about the Metering and Exporting Process (packet Observation Point, sampling rate, Flow timeout interval, etc.), is not specified in [RFC5101].

This document complements the IPFIX protocol specification by providing the IPFIX information model. IPFIX-specific terminology used in this document is defined in Section 2 of [RFC5101]. As in [RFC5101], these IPFIX-specific terms have the first letter of a word capitalized when used in this document.

The use of the term 'information model' is not fully in line with the definition of this term in [RFC3444]. The IPFIX information model does not specify relationships between Information Elements, but also it does not specify a concrete encoding of Information Elements. Besides the encoding used by the IPFIX protocol, other encodings of IPFIX Information Elements can be applied, for example, XML-based encodings. The main part of this document is Section 5, which defines the (extensible) list of Information Elements to be transmitted by the IPFIX protocol. Section 2 defines a template for specifying IPFIX Information Elements in Section 5. Section 3 defines the set of abstract data types that are available for IPFIX Information Elements. Section 6 discusses extensibility of the IPFIX information model.

The main bodies of Sections 2, 3, and 5 were generated from XML documents. The XML-based specification of template, abstract data types, and IPFIX Information Elements can be used for automatically checking syntactical correctness of the specification of IPFIX Information Elements. It can further be used for generating IPFIX protocol implementation code that deals with processing IPFIX Information Elements. Also, code for applications that further process traffic information transmitted via the IPFIX protocol can be generated with the XML specification of IPFIX Information Elements.

For that reason, the XML document that served as a source for Section 5 and the XML schema that served as source for Sections 2 and 3 are attached to this document in Appendices A and B.

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

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 [RFC2119].

2. Properties of IPFIX Protocol Information Elements

2.1. Information Elements Specification Template

Information in messages of the IPFIX protocol is modeled in terms of Information Elements of the IPFIX information model. IPFIX Information Elements are specified in Section 5. For specifying these Information Elements, a template is used that is described below.

All Information Elements specified for the IPFIX protocol either in this document or by any future extension MUST have the following properties defined:

name - A unique and meaningful name for the Information Element.

   elementId - A numeric identifier of the Information Element.  If this
      identifier is used without an enterprise identifier (see [RFC5101]
      and enterpriseId below), then it is globally unique and the list
      of allowed values is administered by IANA.  It is used for compact
      identification of an Information Element when encoding Templates
      in the protocol.

   description - The semantics of this Information Element.  Describes
      how this Information Element is derived from the Flow or other
      information available to the observer.

   dataType - One of the types listed in Section 3.1 of this document or
      in a future extension of the information model.  The type space
      for attributes is constrained to facilitate implementation.  The
      existing type space does however encompass most basic types used
      in modern programming languages, as well as some derived types
      (such as ipv4Address) that are common to this domain and useful to
      distinguish.

   status - The status of the specification of this Information Element.
      Allowed values are 'current', 'deprecated', and 'obsolete'.

Enterprise-specific Information Elements MUST have the following property defined:

   enterpriseId - Enterprises may wish to define Information Elements
      without registering them with IANA, for example, for
      enterprise-internal purposes.  For such Information Elements, the
      Information Element identifier described above is not sufficient
      when the Information Element is used outside the enterprise.  If
      specifications of enterprise-specific Information Elements are
      made public and/or if enterprise-specific identifiers are used by
      the IPFIX protocol outside the enterprise, then the
      enterprise-specific identifier MUST be made globally unique by
      combining it with an enterprise identifier.  Valid values for the
      enterpriseId are defined by IANA as Structure of Management
      Information (SMI) network management private enterprise codes.
      They are defined at http://www.iana.org/assignments/enterprise-
      numbers.

All Information Elements specified for the IPFIX protocol either in this document or by any future extension MAY have the following properties defined:

   dataTypeSemantics - The integral types may be qualified by additional
      semantic details.  Valid values for the data type semantics are
      specified in Section 3.2 of this document or in a future extension
      of the information model.

   units - If the Information Element is a measure of some kind, the
      units identify what the measure is.

   range - Some Information Elements may only be able to take on a
      restricted set of values that can be expressed as a range (e.g., 0
      through 511 inclusive).  If this is the case, the valid inclusive
      range should be specified.

   reference - Identifies additional specifications that more precisely
      define this item or provide additional context for its use.

2.2. Scope of Information Elements

By default, most Information Elements have a scope specified in their definitions.

   o  The Information Elements defined in Sections 5.2 and 5.3 have a
      default of "a specific Metering Process" or of "a specific
      Exporting Process", respectively.

   o  The Information Elements defined in Sections 5.4-5.11 have a scope
      of "a specific Flow".

Within Data Records defined by Option Templates, the IPFIX protocol allows further limiting of the Information Element scope. The new scope is specified by one or more scope fields and defined as the combination of all specified scope values; see Section 3.4.2.1 on IPFIX scopes in [RFC5101].

2.3. Naming Conventions for Information Elements

    The following naming conventions were used for naming Information
    Elements in this document.  It is recommended that extensions of the
    model use the same conventions.

o Names of Information Elements should be descriptive.

   o  Names of Information Elements that are not enterprise-specific
      MUST be unique within the IPFIX information model.
      Enterprise-specific Information Elements SHOULD be prefixed with a
      vendor name.

o Names of Information Elements start with non-capitalized letters.

   o  Composed names use capital letters for the first letter of each
      component (except for the first one).  All other letters are
      non-capitalized, even for acronyms.  Exceptions are made for
      acronyms containing non-capitalized letter, such as 'IPv4' and
      'IPv6'.  Examples are sourceMacAddress and destinationIPv4Address.

   o  Middleboxes [RFC3234] may change Flow properties, such as the
      Differentiated Service Code Point (DSCP) value or the source IP
      address.  If an IPFIX Observation Point is located in the path of
      a Flow before one or more middleboxes that potentially modify
      packets of the Flow, then it may be desirable to also report Flow
      properties after the modification performed by the middleboxes.
      An example is an Observation Point before a packet marker changing
      a packet's IPv4 Type of Service (TOS) field that is encoded in
      Information Element classOfServiceIPv4.  Then the value observed
      and reported by Information Element classOfServiceIPv4 is valid at
      the Observation Point, but not after the packet passed the packet
      marker.  For reporting the change value of the TOS field, the
      IPFIX information model uses Information Elements that have a name
      prefix "post", for example, "postClassOfServiceIPv4".  Information
      Elements with prefix "post" report on Flow properties that are not
      necessarily observed at the Observation Point, but which are
      obtained within the Flow's Observation Domain by other means
      considered to be sufficiently reliable, for example, by analyzing
      the packet marker's marking tables.

3. Type Space

This section describes the abstract data types that can be used for the specification of IPFIX Information Elements in Section 4. Section 3.1 describes the set of abstract data types.

Abstract data types unsigned8, unsigned16, unsigned32, unsigned64, signed8, signed16, signed32, and signed64 are integral data types. As described in Section 3.2, their data type semantics can be further specified, for example, by 'totalCounter', 'deltaCounter', 'identifier', or 'flags'.

3.1. Abstract Data Types

This section describes the set of valid abstract data types of the IPFIX information model. Note that further abstract data types may be specified by future extensions of the IPFIX information model.

3.1.1. unsigned8

The type "unsigned8" represents a non-negative integer value in the range of 0 to 255.

3.1.2. unsigned16

The type "unsigned16" represents a non-negative integer value in the range of 0 to 65535.

3.1.3. unsigned32

The type "unsigned32" represents a non-negative integer value in the range of 0 to 4294967295.

3.1.4. unsigned64

The type "unsigned64" represents a non-negative integer value in the range of 0 to 18446744073709551615.

3.1.5. signed8

The type "signed8" represents an integer value in the range of -128 to 127.

3.1.6. signed16

The type "signed16" represents an integer value in the range of -32768 to 32767.

3.1.7. signed32

The type "signed32" represents an integer value in the range of -2147483648 to 2147483647.

3.1.8. signed64

The type "signed64" represents an integer value in the range of -9223372036854775808 to 9223372036854775807.

3.1.9. float32

The type "float32" corresponds to an IEEE single-precision 32-bit floating point type as defined in [IEEE.754.1985].

3.1.10. float64

The type "float64" corresponds to an IEEE double-precision 64-bit floating point type as defined in [IEEE.754.1985].

3.1.11. boolean

The type "boolean" represents a binary value. The only allowed values are "true" and "false".

3.1.12. macAddress

The type "macAddress" represents a string of 6 octets.

3.1.13. octetArray

The type "octetArray" represents a finite-length string of octets.

3.1.14. string

The type "string" represents a finite-length string of valid characters from the Unicode character encoding set [ISO.10646- 1.1993]. Unicode allows for ASCII [ISO.646.1991] and many other international character sets to be used.

3.1.15. dateTimeSeconds

The type "dateTimeSeconds" represents a time value in units of seconds based on coordinated universal time (UTC). The choice of an epoch, for example, 00:00 UTC, January 1, 1970, is left to corresponding encoding specifications for this type, for example, the IPFIX protocol specification. Leap seconds are excluded. Note that transformation of values might be required between different encodings if different epoch values are used.

3.1.16. dateTimeMilliseconds

The type "dateTimeMilliseconds" represents a time value in units of milliseconds based on coordinated universal time (UTC). The choice of an epoch, for example, 00:00 UTC, January 1, 1970, is left to corresponding encoding specifications for this type, for example, the IPFIX protocol specification. Leap seconds are excluded. Note that transformation of values might be required between different encodings if different epoch values are used.

3.1.17. dateTimeMicroseconds

The type "dateTimeMicroseconds" represents a time value in units of microseconds based on coordinated universal time (UTC). The choice of an epoch, for example, 00:00 UTC, January 1, 1970, is left to

corresponding encoding specifications for this type, for example, the IPFIX protocol specification. Leap seconds are excluded. Note that transformation of values might be required between different encodings if different epoch values are used.

3.1.18. dateTimeNanoseconds

The type "dateTimeNanoseconds" represents a time value in units of nanoseconds based on coordinated universal time (UTC). The choice of an epoch, for example, 00:00 UTC, January 1, 1970, is left to corresponding encoding specifications for this type, for example, the IPFIX protocol specification. Leap seconds are excluded. Note that transformation of values might be required between different encodings if different epoch values are used.

3.1.19. ipv4Address

The type "ipv4Address" represents a value of an IPv4 address.

3.1.20. ipv6Address

The type "ipv6Address" represents a value of an IPv6 address.

3.2. Data Type Semantics

This section describes the set of valid data type semantics of the IPFIX information model. Note that further data type semantics may be specified by future extensions of the IPFIX information model.

3.2.1. quantity

A quantity value represents a discrete measured value pertaining to the record. This is distinguished from counters that represent an ongoing measured value whose "odometer" reading is captured as part of a given record. If no semantic qualifier is given, the Information Elements that have an integral data type should behave as a quantity.

3.2.2. totalCounter

An integral value reporting the value of a counter. Counters are unsigned and wrap back to zero after reaching the limit of the type. For example, an unsigned64 with counter semantics will continue to increment until reaching the value of 2**64 - 1. At this point, the next increment will wrap its value to zero and continue counting from zero. The semantics of a total counter is similar to the semantics of counters used in SNMP, such as Counter32 defined in RFC 2578 [RFC2578]. The only difference between total counters and counters

used in SNMP is that the total counters have an initial value of 0. A total counter counts independently of the export of its value.

3.2.3. deltaCounter

An integral value reporting the value of a counter. Counters are unsigned and wrap back to zero after reaching the limit of the type. For example, an unsigned64 with counter semantics will continue to increment until reaching the value of 2**64 - 1. At this point, the next increment will wrap its value to zero and continue counting from zero. The semantics of a delta counter is similar to the semantics of counters used in SNMP, such as Counter32 defined in RFC 2578 [RFC2578]. The only difference between delta counters and counters used in SNMP is that the delta counters have an initial value of 0. A delta counter is reset to 0 each time its value is exported.

3.2.4. identifier

An integral value that serves as an identifier. Specifically, mathematical operations on two identifiers (aside from the equality operation) are meaningless. For example, Autonomous System ID 1 * Autonomous System ID 2 is meaningless.

3.2.5. flags

An integral value that actually represents a set of bit fields. Logical operations are appropriate on such values, but not other mathematical operations. Flags should always be of an unsigned type.

4. Information Element Identifiers

All Information Elements defined in Section 5 of this document or in future extensions of the IPFIX information model have their identifiers assigned by IANA. Their identifiers can be retrieved at http://www.iana.org/assignments/ipfix.

The value of these identifiers is in the range of 1-32767. Within this range, Information Element identifier values in the sub-range of 1-127 are compatible with field types used by NetFlow version 9 [RFC3954].

   +---------------------------------+---------------------------------+
   | Range of IANA-assigned          | Description                     |
   | Information Element identifiers |                                 |
   +---------------------------------+---------------------------------+
   | 0                               | Reserved.                       |
   | 1-127                           | Information Element identifiers |
   |                                 | compatible with NetFlow version |
   |                                 | 9 field types [RFC3954].        |
   | 128-32767                       | Further Information Element     |
   |                                 | identifiers.                    |
   +---------------------------------+---------------------------------+

Enterprise-specific Information Element identifiers have the same range of 1-32767, but they are coupled with an additional enterprise identifier. For enterprise-specific Information Elements, Information Element identifier 0 is also reserved.

Enterprise-specific Information Element identifiers can be chosen by an enterprise arbitrarily within the range of 1-32767. The same identifier may be assigned by other enterprises for different purposes.

Still, Collecting Processes can distinguish these Information Elements because the Information Element identifier is coupled with an enterprise identifier.

Enterprise identifiers MUST be registered as SMI network management private enterprise code numbers with IANA. The registry can be found at http://www.iana.org/assignments/enterprise-numbers.

The following list gives an overview of the Information Element identifiers that are specified in Section 5 and are compatible with field types used by NetFlow version 9 [RFC3954].

   +----+----------------------------+-------+-------------------------+
   | ID | Name                       |    ID | Name                    |
   +----+----------------------------+-------+-------------------------+
   |  1 | octetDeltaCount            |    43 | RESERVED                |
   |  2 | packetDeltaCount           |    44 | sourceIPv4Prefix        |
   |  3 | RESERVED                   |    45 | destinationIPv4Prefix   |
   |  4 | protocolIdentifier         |    46 | mplsTopLabelType        |
   |  5 | ipClassOfService           |    47 | mplsTopLabelIPv4Address |
   |  6 | tcpControlBits             | 48-51 | RESERVED                |
   |  7 | sourceTransportPort        |    52 | minimumTTL              |
   |  8 | sourceIPv4Address          |    53 | maximumTTL              |
   |  9 | sourceIPv4PrefixLength     |    54 | fragmentIdentification  |
   | 10 | ingressInterface           |    55 | postIpClassOfService    |
   | 11 | destinationTransportPort   |    56 | sourceMacAddress        |
   | 12 | destinationIPv4Address     |    57 |postDestinationMacAddress|
   | 13 | destinationIPv4PrefixLength|    58 | vlanId                  |
   | 14 | egressInterface            |    59 | postVlanId              |
   | 15 | ipNextHopIPv4Address       |    60 | ipVersion               |
   | 16 | bgpSourceAsNumber          |    61 | flowDirection           |
   | 17 | bgpDestinationAsNumber     |    62 | ipNextHopIPv6Address    |
   | 18 | bgpNexthopIPv4Address      |    63 | bgpNexthopIPv6Address   |
   | 19 | postMCastPacketDeltaCount  |    64 | ipv6ExtensionHeaders    |
   | 20 | postMCastOctetDeltaCount   | 65-69 | RESERVED                |
   | 21 | flowEndSysUpTime           |    70 | mplsTopLabelStackSection|
   | 22 | flowStartSysUpTime         |    71 | mplsLabelStackSection2  |
   | 23 | postOctetDeltaCount        |    72 | mplsLabelStackSection3  |
   | 24 | postPacketDeltaCount       |    73 | mplsLabelStackSection4  |
   | 25 | minimumIpTotalLength       |    74 | mplsLabelStackSection5  |
   | 26 | maximumIpTotalLength       |    75 | mplsLabelStackSection6  |
   | 27 | sourceIPv6Address          |    76 | mplsLabelStackSection7  |
   | 28 | destinationIPv6Address     |    77 | mplsLabelStackSection8  |
   | 29 | sourceIPv6PrefixLength     |    78 | mplsLabelStackSection9  |
   | 30 | destinationIPv6PrefixLength|    79 | mplsLabelStackSection10 |
   | 31 | flowLabelIPv6              |    80 | destinationMacAddress   |
   | 32 | icmpTypeCodeIPv4           |    81 | postSourceMacAddress    |
   | 33 | igmpType                   | 82-84 | RESERVED                |
   | 34 | RESERVED                   |    85 | octetTotalCount         |
   | 35 | RESERVED                   |    86 | packetTotalCount        |
   | 36 | flowActiveTimeout          |    87 | RESERVED                |
   | 37 | flowIdleTimeout            |    88 | fragmentOffset          |
   | 38 | RESERVED                   |    89 | RESERVED                |
   | 39 | RESERVED                   |    90 |mplsVpnRouteDistinguisher|
   | 40 | exportedOctetTotalCount    |91-127 | RESERVED                |
   | 41 | exportedMessageTotalCount  |       |                         |
   | 42 |exportedFlowRecordTotalCount|       |                         |
   +----+----------------------------+-------+-------------------------+

The following list gives an overview of the Information Element identifiers that are specified in Section 5 and extends the list of Information Element identifiers specified already in [RFC3954].

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   | 128 | bgpNextAdjacentAsNumber   | 169 | destinationIPv6Prefix     |
   | 129 | bgpPrevAdjacentAsNumber   | 170 | sourceIPv6Prefix          |
   | 130 | exporterIPv4Address       | 171 | postOctetTotalCount       |
   | 131 | exporterIPv6Address       | 172 | postPacketTotalCount      |
   | 132 | droppedOctetDeltaCount    | 173 | flowKeyIndicator          |
   | 133 | droppedPacketDeltaCount   | 174 | postMCastPacketTotalCount |
   | 134 | droppedOctetTotalCount    | 175 | postMCastOctetTotalCount  |
   | 135 | droppedPacketTotalCount   | 176 | icmpTypeIPv4              |
   | 136 | flowEndReason             | 177 | icmpCodeIPv4              |
   | 137 | commonPropertiesId        | 178 | icmpTypeIPv6              |
   | 138 | observationPointId        | 179 | icmpCodeIPv6              |
   | 139 | icmpTypeCodeIPv6          | 180 | udpSourcePort             |
   | 140 | mplsTopLabelIPv6Address   | 181 | udpDestinationPort        |
   | 141 | lineCardId                | 182 | tcpSourcePort             |
   | 142 | portId                    | 183 | tcpDestinationPort        |
   | 143 | meteringProcessId         | 184 | tcpSequenceNumber         |
   | 144 | exportingProcessId        | 185 | tcpAcknowledgementNumber  |
   | 145 | templateId                | 186 | tcpWindowSize             |
   | 146 | wlanChannelId             | 187 | tcpUrgentPointer          |
   | 147 | wlanSSID                  | 188 | tcpHeaderLength           |
   | 148 | flowId                    | 189 | ipHeaderLength            |
   | 149 | observationDomainId       | 190 | totalLengthIPv4           |
   | 150 | flowStartSeconds          | 191 | payloadLengthIPv6         |
   | 151 | flowEndSeconds            | 192 | ipTTL                     |
   | 152 | flowStartMilliseconds     | 193 | nextHeaderIPv6            |
   | 153 | flowEndMilliseconds       | 194 | mplsPayloadLength         |
   | 154 | flowStartMicroseconds     | 195 | ipDiffServCodePoint       |
   | 155 | flowEndMicroseconds       | 196 | ipPrecedence              |
   | 156 | flowStartNanoseconds      | 197 | fragmentFlags             |
   | 157 | flowEndNanoseconds        | 198 | octetDeltaSumOfSquares    |
   | 158 | flowStartDeltaMicroseconds| 199 | octetTotalSumOfSquares    |
   | 159 | flowEndDeltaMicroseconds  | 200 | mplsTopLabelTTL           |
   | 160 | systemInitTimeMilliseconds| 201 | mplsLabelStackLength      |
   | 161 | flowDurationMilliseconds  | 202 | mplsLabelStackDepth       |
   | 162 | flowDurationMicroseconds  | 203 | mplsTopLabelExp           |
   | 163 | observedFlowTotalCount    | 204 | ipPayloadLength           |
   | 164 | ignoredPacketTotalCount   | 205 | udpMessageLength          |
   | 165 | ignoredOctetTotalCount    | 206 | isMulticast               |
   | 166 | notSentFlowTotalCount     | 207 | ipv4IHL                   |
   | 167 | notSentPacketTotalCount   | 208 | ipv4Options               |
   | 168 | notSentOctetTotalCount    | 209 | tcpOptions                |

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   | 210 | paddingOctets             | 218 | tcpSynTotalCount          |
   | 211 | collectorIPv4Address      | 219 | tcpFinTotalCount          |
   | 212 | collectorIPv6Address      | 220 | tcpRstTotalCount          |
   | 213 | exportInterface           | 221 | tcpPshTotalCount          |
   | 214 | exportProtocolVersion     | 222 | tcpAckTotalCount          |
   | 215 | exportTransportProtocol   | 223 | tcpUrgTotalCount          |
   | 216 | collectorTransportPort    | 224 | ipTotalLength             |
   | 217 | exporterTransportPort     | 237 | postMplsTopLabelExp       |
   |     |                           | 238 | tcpWindowScale            |
   +-----+---------------------------+-----+---------------------------+

5. Information Elements

This section describes the Information Elements of the IPFIX information model. The elements are grouped into 12 groups according to their semantics and their applicability:

   1.   Identifiers
   2.   Metering and Exporting Process Configuration
   3.   Metering and Exporting Process Statistics
   4.   IP Header Fields
   5.   Transport Header Fields
   6.   Sub-IP Header Fields
   7.   Derived Packet Properties
   8.   Min/Max Flow Properties
   9.   Flow Timestamps
   10.  Per-Flow Counters
   11.  Miscellaneous Flow Properties
   12.  Padding

The Information Elements that are derived from fields of packets or from packet treatment, such as the Information Elements in groups 4-7, can typically serve as Flow Keys used for mapping packets to Flows.

If they do not serve as Flow Keys, their value may change from packet to packet within a single Flow. For Information Elements with values that are derived from fields of packets or from packet treatment and for which the value may change from packet to packet within a single Flow, the IPFIX information model defines that their value is determined by the first packet observed for the corresponding Flow, unless the description of the Information Element explicitly specifies a different semantics. This simple rule allows writing all Information Elements related to header fields once when the first packet of the Flow is observed. For further observed packets of the same Flow, only Flow properties that depend on more than one packet, such as the Information Elements in groups 8-11, need to be updated.

Information Elements with a name having the "post" prefix, for example, "postClassOfServiceIPv4", do not report properties that were actually observed at the Observation Point, but retrieved by other means within the Observation Domain. These Information Elements can be used if there are middlebox functions within the Observation Domain changing Flow properties after packets passed the Observation Point.

Information Elements in this section use the reference property to reference [RFC0768], [RFC0791], [RFC0792], [RFC0793], [RFC1108], [RFC1112], [RFC1191], [RFC1323], [RFC1385], [RFC1812], [RFC1930], [RFC2113], [RFC2119], [RFC2460], [RFC2675], [RFC2863], [RFC3031], [RFC3032], [RFC3193], [RFC3234], [RFC3260], [RFC3270], [RFC3376], [RFC3954], [RFC4271], [RFC4291], [RFC4302], [RFC4303], [RFC4364], [RFC4382], [RFC4443], [RFC4960], [RFC5036], [IEEE.802-11.1999], [IEEE.802-1Q.2003], and [IEEE.802-3.2002].

5.1. Identifiers

Information Elements grouped in the table below are identifying components of the IPFIX architecture, of an IPFIX Device, or of the IPFIX protocol. All of them have an integral abstract data type and data type semantics "identifier" as described in Section 3.2.4.

Typically, some of them are used for limiting scopes of other Information Elements. However, other Information Elements MAY be used for limiting scopes. Note also that all Information Elements listed below MAY be used for other purposes than limiting scopes.

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   | 141 | lineCardId                | 148 | flowId                    |
   | 142 | portId                    | 145 | templateId                |
   |  10 | ingressInterface          | 149 | observationDomainId       |
   |  14 | egressInterface           | 138 | observationPointId        |
   | 143 | meteringProcessId         | 137 | commonPropertiesId        |
   | 144 | exportingProcessId        |     |                           |
   +-----+---------------------------+-----+---------------------------+

5.1.1. lineCardId

   Description:
      An identifier of a line card that is unique per IPFIX Device
      hosting an Observation Point.  Typically, this Information Element
      is used for limiting the scope of other Information Elements.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 141
   Status: current

5.1.2. portId

   Description:
      An identifier of a line port that is unique per IPFIX Device
      hosting an Observation Point.  Typically, this Information Element
      is used for limiting the scope of other Information Elements.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 142
   Status: current

5.1.3. ingressInterface

   Description:
      The index of the IP interface where packets of this Flow are being
      received.  The value matches the value of managed object 'ifIndex'
      as defined in RFC 2863.  Note that ifIndex values are not assigned
      statically to an interface and that the interfaces may be
      renumbered every time the device's management system is
      re-initialized, as specified in RFC 2863.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 10
   Status: current
   Reference:
      See RFC 2863 for the definition of the ifIndex object.

5.1.4. egressInterface

   Description:
      The index of the IP interface where packets of this Flow are being
      sent.  The value matches the value of managed object 'ifIndex' as
      defined in RFC 2863.  Note that ifIndex values are not assigned
      statically to an interface and that the interfaces may be
      renumbered every time the device's management system is
      re-initialized, as specified in RFC 2863.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 14
   Status: current
   Reference:
      See RFC 2863 for the definition of the ifIndex object.

5.1.5. meteringProcessId

   Description:
      An identifier of a Metering Process that is unique per IPFIX
      Device.  Typically, this Information Element is used for limiting
      the scope of other Information Elements.  Note that process
      identifiers are typically assigned dynamically.  The Metering
      Process may be re-started with a different ID.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 143
   Status: current

5.1.6. exportingProcessId

   Description:
      An identifier of an Exporting Process that is unique per IPFIX
      Device.  Typically, this Information Element is used for limiting
      the scope of other Information Elements.  Note that process
      identifiers are typically assigned dynamically.  The Exporting
      Process may be re-started with a different ID.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 144
   Status: current

5.1.7. flowId

   Description:
      An identifier of a Flow that is unique within an Observation
      Domain.  This Information Element can be used to distinguish
      between different Flows if Flow Keys such as IP addresses and port
      numbers are not reported or are reported in separate records.
   Abstract Data Type: unsigned64
   Data Type Semantics: identifier
   ElementId: 148
   Status: current

5.1.8. templateId

   Description:
      An identifier of a Template that is locally unique within a
      combination of a Transport session and an Observation Domain.
      Template IDs 0-255 are reserved for Template Sets, Options
      Template Sets, and other reserved Sets yet to be created.
      Template IDs of Data Sets are numbered from 256 to 65535.
      Typically, this Information Element is used for limiting the scope
      of other Information Elements.  Note that after a re-start of the
      Exporting Process Template identifiers may be re-assigned.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 145
   Status: current

5.1.9. observationDomainId

   Description:
      An identifier of an Observation Domain that is locally unique to
      an Exporting Process.  The Exporting Process uses the Observation
      Domain ID to uniquely identify to the Collecting Process the
      Observation Domain where Flows were metered.  It is RECOMMENDED
      that this identifier is also unique per IPFIX Device.  A value of
      0 indicates that no specific Observation Domain is identified by
      this Information Element.  Typically, this Information Element is
      used for limiting the scope of other Information Elements.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 149
   Status: current

5.1.10. observationPointId

   Description:
      An identifier of an Observation Point that is unique per
      Observation Domain.  It is RECOMMENDED that this identifier is
      also unique per IPFIX Device.  Typically, this Information Element
      is used for limiting the scope of other Information Elements.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 138
   Status: current

5.1.11. commonPropertiesId

   Description:
      An identifier of a set of common properties that is unique per
      Observation Domain and Transport Session.  Typically, this
      Information Element is used to link to information reported in
      separate Data Records.
   Abstract Data Type: unsigned64
   Data Type Semantics: identifier
   ElementId: 137
   Status: current

5.2. Metering and Exporting Process Configuration

Information Elements in this section describe the configuration of the Metering Process or the Exporting Process. The set of these Information Elements is listed in the table below.

   +-----+--------------------------+-----+----------------------------+
   |  ID | Name                     |  ID | Name                       |
   +-----+--------------------------+-----+----------------------------+
   | 130 | exporterIPv4Address      | 213 | exportInterface            |
   | 131 | exporterIPv6Address      | 214 | exportProtocolVersion      |
   | 217 | exporterTransportPort    | 215 | exportTransportProtocol    |
   | 211 | collectorIPv4Address     | 216 | collectorTransportPort     |
   | 212 | collectorIPv6Address     | 173 | flowKeyIndicator           |
   +-----+--------------------------+-----+----------------------------+

5.2.1. exporterIPv4Address

   Description:
      The IPv4 address used by the Exporting Process.  This is used by
      the Collector to identify the Exporter in cases where the identity
      of the Exporter may have been obscured by the use of a proxy.
   Abstract Data Type: ipv4Address
   Data Type Semantics: identifier
   ElementId: 130
   Status: current

5.2.2. exporterIPv6Address

   Description:
      The IPv6 address used by the Exporting Process.  This is used by
      the Collector to identify the Exporter in cases where the identity
      of the Exporter may have been obscured by the use of a proxy.
   Abstract Data Type: ipv6Address
   Data Type Semantics: identifier
   ElementId: 131
   Status: current

5.2.3. exporterTransportPort

   Description:
      The source port identifier from which the Exporting Process sends
      Flow information.  For the transport protocols UDP, TCP, and SCTP,
      this is the source port number.  This field MAY also be used for
      future transport protocols that have 16-bit source port
      identifiers.  This field may be useful for distinguishing multiple
      Exporting Processes that use the same IP address.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 217
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP source port field.  See
      RFC 793 for the definition of the TCP source port field.  See RFC
      4960 for the definition of SCTP.  Additional information on
      defined UDP and TCP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.2.4. collectorIPv4Address

   Description:
      An IPv4 address to which the Exporting Process sends Flow
      information.
   Abstract Data Type: ipv4Address
   Data Type Semantics: identifier
   ElementId: 211
   Status: current

5.2.5. collectorIPv6Address

   Description:
      An IPv6 address to which the Exporting Process sends Flow
      information.
   Abstract Data Type: ipv6Address
   Data Type Semantics: identifier
   ElementId: 212
   Status: current

5.2.6. exportInterface

   Description:
      The index of the interface from which IPFIX Messages sent by the
      Exporting Process to a Collector leave the IPFIX Device.  The
      value matches the value of managed object 'ifIndex' as defined in
      RFC 2863.  Note that ifIndex values are not assigned statically to
      an interface and that the interfaces may be renumbered every time
      the device's management system is re-initialized, as specified in
      RFC 2863.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 213
   Status: current
   Reference:
      See RFC 2863 for the definition of the ifIndex object.

5.2.7. exportProtocolVersion

   Description:
      The protocol version used by the Exporting Process for sending
      Flow information.  The protocol version is given by the value of
      the Version Number field in the Message Header.  The protocol
      version is 10 for IPFIX and 9 for NetFlow version 9.  A value of 0
      indicates that no export protocol is in use.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 214
   Status: current
   Reference:
      See the IPFIX protocol specification [RFC5101] for the definition
      of the IPFIX Message Header.
      See RFC 3954 for the definition of the NetFlow version 9 message
      header.

5.2.8. exportTransportProtocol

   Description:
      The value of the protocol number used by the Exporting Process for
      sending Flow information.  The protocol number identifies the IP
      packet payload type.  Protocol numbers are defined in the IANA
      Protocol Numbers registry.
      In Internet Protocol version 4 (IPv4), this is carried in the
      Protocol field.  In Internet Protocol version 6 (IPv6), this is
      carried in the Next Header field in the last extension header of
      the packet.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 215
   Status: current
   Reference:
      See RFC 791 for the specification of the IPv4 protocol field.  See
      RFC 2460 for the specification of the IPv6 protocol field.  See
      the list of protocol numbers assigned by IANA at
      http://www.iana.org/assignments/protocol-numbers.

5.2.9. collectorTransportPort

   Description:
      The destination port identifier to which the Exporting Process
      sends Flow information.  For the transport protocols UDP, TCP, and
      SCTP, this is the destination port number.  This field MAY also be
      used for future transport protocols that have 16-bit source port
      identifiers.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 216
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP destination port field.
      See RFC 793 for the definition of the TCP destination port field.
      See RFC 4960 for the definition of SCTP.
      Additional information on defined UDP and TCP port numbers can be
      found at http://www.iana.org/assignments/port-numbers.

5.2.10. flowKeyIndicator

   Description:
      This set of bit fields is used for marking the Information
      Elements of a Data Record that serve as Flow Key.  Each bit
      represents an Information Element in the Data Record with the n-th
      bit representing the n-th Information Element.  A bit set to value
      1 indicates that the corresponding Information Element is a Flow
      Key of the reported Flow.  A bit set to value 0 indicates that
      this is not the case.
      If the Data Record contains more than 64 Information Elements, the
      corresponding Template SHOULD be designed such that all Flow Keys
      are among the first 64 Information Elements, because the
      flowKeyIndicator only contains 64 bits.  If the Data Record
      contains less than 64 Information Elements, then the bits in the
      flowKeyIndicator for which no corresponding Information Element
      exists MUST have the value 0.
   Abstract Data Type: unsigned64
   Data Type Semantics: flags
   ElementId: 173
   Status: current

5.3. Metering and Exporting Process Statistics

Information Elements in this section describe statistics of the Metering Process and/or the Exporting Process. The set of these Information Elements is listed in the table below.

   +-----+-----------------------------+-----+-------------------------+
   |  ID | Name                        |  ID | Name                    |
   +-----+-----------------------------+-----+-------------------------+
   |  41 | exportedMessageTotalCount   | 165 | ignoredOctetTotalCount  |
   |  40 | exportedOctetTotalCount     | 166 | notSentFlowTotalCount   |
   |  42 | exportedFlowRecordTotalCount| 167 | notSentPacketTotalCount |
   | 163 | observedFlowTotalCount      | 168 | notSentOctetTotalCount  |
   | 164 | ignoredPacketTotalCount     |     |                         |
   +-----+-----------------------------+-----+-------------------------+

5.3.1. exportedMessageTotalCount

   Description:
      The total number of IPFIX Messages that the Exporting Process has
      sent since the Exporting Process (re-)initialization to a
      particular Collecting Process.  The reported number excludes the
      IPFIX Message that carries the counter value.  If this Information
      Element is sent to a particular Collecting Process, then by
      default it specifies the number of IPFIX Messages sent to this
      Collecting Process.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 41
   Status: current
   Units: messages

5.3.2. exportedOctetTotalCount

   Description:
      The total number of octets that the Exporting Process has sent
      since the Exporting Process (re-)initialization to a particular
      Collecting Process.  The value of this Information Element is
      calculated by summing up the IPFIX Message Header length values of
      all IPFIX Messages that were successfully sent to the Collecting
      Process.  The reported number excludes octets in the IPFIX Message
      that carries the counter value.  If this Information Element is
      sent to a particular Collecting Process, then by default it
      specifies the number of octets sent to this Collecting Process.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 40
   Status: current

   Units: octets

5.3.3. exportedFlowRecordTotalCount

   Description:
      The total number of Flow Records that the Exporting Process has
      sent as Data Records since the Exporting Process
      (re-)initialization to a particular Collecting Process.  The
      reported number excludes Flow Records in the IPFIX Message that
      carries the counter value.  If this Information Element is sent to
      a particular Collecting Process, then by default it specifies the
      number of Flow Records sent to this process.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 42
   Status: current
   Units: flows

5.3.4. observedFlowTotalCount

   Description:
      The total number of Flows observed in the Observation Domain since
      the Metering Process (re-)initialization for this Observation
      Point.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 163
   Status: current
   Units: flows

5.3.5. ignoredPacketTotalCount

   Description:
      The total number of observed IP packets that the Metering Process
      did not process since the (re-)initialization of the Metering
      Process.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 164
   Status: current
   Units: packets

5.3.6. ignoredOctetTotalCount

   Description:
      The total number of octets in observed IP packets (including the
      IP header) that the Metering Process did not process since the
      (re-)initialization of the Metering Process.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 165
   Status: current
   Units: octets

5.3.7. notSentFlowTotalCount

   Description:
      The total number of Flow Records that were generated by the
      Metering Process and dropped by the Metering Process or by the
      Exporting Process instead of being sent to the Collecting Process.
      There are several potential reasons for this including resource
      shortage and special Flow export policies.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 166
   Status: current
   Units: flows

5.3.8. notSentPacketTotalCount

   Description:
      The total number of packets in Flow Records that were generated by
      the Metering Process and dropped by the Metering Process or by the
      Exporting Process instead of being sent to the Collecting Process.
      There are several potential reasons for this including resource
      shortage and special Flow export policies.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 167
   Status: current
   Units: packets

5.3.9. notSentOctetTotalCount

   Description:
      The total number of octets in packets in Flow Records that were
      generated by the Metering Process and dropped by the Metering
      Process or by the Exporting Process instead of being sent to the
      Collecting Process.  There are several potential reasons for this
      including resource shortage and special Flow export policies.
   Abstract Data Type: unsigned64
   Data Type Semantics: totalCounter
   ElementId: 168
   Status: current
   Units: octets

5.4. IP Header Fields

Information Elements in this section indicate values of IP header fields or are derived from IP header field values in combination with further information.

   +-----+----------------------------+-----+--------------------------+
   |  ID | Name                       |  ID | Name                     |
   +-----+----------------------------+-----+--------------------------+
   |  60 | ipVersion                  | 193 | nextHeaderIPv6           |
   |   8 | sourceIPv4Address          | 195 | ipDiffServCodePoint      |
   |  27 | sourceIPv6Address          | 196 | ipPrecedence             |
   |   9 | sourceIPv4PrefixLength     |   5 | ipClassOfService         |
   |  29 | sourceIPv6PrefixLength     |  55 | postIpClassOfService     |
   |  44 | sourceIPv4Prefix           |  31 | flowLabelIPv6            |
   | 170 | sourceIPv6Prefix           | 206 | isMulticast              |
   |  12 | destinationIPv4Address     |  54 | fragmentIdentification   |
   |  28 | destinationIPv6Address     |  88 | fragmentOffset           |
   |  13 | destinationIPv4PrefixLength| 197 | fragmentFlags            |
   |  30 | destinationIPv6PrefixLength| 189 | ipHeaderLength           |
   |  45 | destinationIPv4Prefix      | 207 | ipv4IHL                  |
   | 169 | destinationIPv6Prefix      | 190 | totalLengthIPv4          |
   | 192 | ipTTL                      | 224 | ipTotalLength            |
   |   4 | protocolIdentifier         | 191 | payloadLengthIPv6        |
   +-----+----------------------------+-----+--------------------------+

5.4.1. ipVersion

   Description:
      The IP version field in the IP packet header.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 60
   Status: current

   Reference:
      See RFC 791 for the definition of the version field in the IPv4
      packet header.  See RFC 2460 for the definition of the version
      field in the IPv6 packet header.  Additional information on
      defined version numbers can be found at
      http://www.iana.org/assignments/version-numbers.

5.4.2. sourceIPv4Address

   Description:
      The IPv4 source address in the IP packet header.
   Abstract Data Type: ipv4Address
   Data Type Semantics: identifier
   ElementId: 8
   Status: current
   Reference:
      See RFC 791 for the definition of the IPv4 source address field.

5.4.3. sourceIPv6Address

   Description:
      The IPv6 source address in the IP packet header.
   Abstract Data Type: ipv6Address
   Data Type Semantics: identifier
   ElementId: 27
   Status: current
   Reference:
      See RFC 2460 for the definition of the Source Address field in the
      IPv6 header.

5.4.4. sourceIPv4PrefixLength

   Description:
      The number of contiguous bits that are relevant in the
      sourceIPv4Prefix Information Element.
   Abstract Data Type: unsigned8
   ElementId: 9
   Status: current
   Units: bits
   Range: The valid range is 0-32.

5.4.5. sourceIPv6PrefixLength

   Description:
      The number of contiguous bits that are relevant in the
      sourceIPv6Prefix Information Element.
   Abstract Data Type: unsigned8
   ElementId: 29
   Status: current
   Units: bits
   Range: The valid range is 0-128.

5.4.6. sourceIPv4Prefix

   Description:
      IPv4 source address prefix.
   Abstract Data Type: ipv4Address
   ElementId: 44
   Status: current

5.4.7. sourceIPv6Prefix

   Description:
      IPv6 source address prefix.
   Abstract Data Type: ipv6Address
   ElementId: 170
   Status: current

5.4.8. destinationIPv4Address

   Description:
      The IPv4 destination address in the IP packet header.
   Abstract Data Type: ipv4Address
   Data Type Semantics: identifier
   ElementId: 12
   Status: current
   Reference:
      See RFC 791 for the definition of the IPv4 destination address
      field.

5.4.9. destinationIPv6Address

   Description:
      The IPv6 destination address in the IP packet header.
   Abstract Data Type: ipv6Address
   Data Type Semantics: identifier
   ElementId: 28
   Status: current
   Reference:
      See RFC 2460 for the definition of the Destination Address field
      in the IPv6 header.

5.4.10. destinationIPv4PrefixLength

   Description:
      The number of contiguous bits that are relevant in the
      destinationIPv4Prefix Information Element.
   Abstract Data Type: unsigned8
   ElementId: 13
   Status: current
   Units: bits
   Range: The valid range is 0-32.

5.4.11. destinationIPv6PrefixLength

   Description:
      The number of contiguous bits that are relevant in the
      destinationIPv6Prefix Information Element.
   Abstract Data Type: unsigned8
   ElementId: 30
   Status: current
   Units: bits
   Range: The valid range is 0-128.

5.4.12. destinationIPv4Prefix

   Description:
      IPv4 destination address prefix.
   Abstract Data Type: ipv4Address
   ElementId: 45
   Status: current

5.4.13. destinationIPv6Prefix

   Description:
      IPv6 destination address prefix.
   Abstract Data Type: ipv6Address
   ElementId: 169
   Status: current

5.4.14. ipTTL

   Description:
      For IPv4, the value of the Information Element matches the value
      of the Time to Live (TTL) field in the IPv4 packet header.  For
      IPv6, the value of the Information Element matches the value of
      the Hop Limit field in the IPv6 packet header.
   Abstract Data Type: unsigned8
   ElementId: 192
   Status: current
   Units: hops
   Reference:
      See RFC 791 for the definition of the IPv4 Time to Live field.
      See RFC 2460 for the definition of the IPv6 Hop Limit field.

5.4.15. protocolIdentifier

   Description:
      The value of the protocol number in the IP packet header.  The
      protocol number identifies the IP packet payload type.  Protocol
      numbers are defined in the IANA Protocol Numbers registry.  In
      Internet Protocol version 4 (IPv4), this is carried in the
      Protocol field.  In Internet Protocol version 6 (IPv6), this is
      carried in the Next Header field in the last extension header of
      the packet.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 4
   Status: current
   Reference:
      See RFC 791 for the specification of the IPv4 protocol field.  See
      RFC 2460 for the specification of the IPv6 protocol field.  See
      the list of protocol numbers assigned by IANA at
      http://www.iana.org/assignments/protocol-numbers.

5.4.16. nextHeaderIPv6

   Description:
      The value of the Next Header field of the IPv6 header.  The value
      identifies the type of the following IPv6 extension header or of
      the following IP payload.  Valid values are defined in the IANA
      Protocol Numbers registry.
   Abstract Data Type: unsigned8
   ElementId: 193
   Status: current
   Reference:
      See RFC 2460 for the definition of the IPv6 Next Header field.
      See the list of protocol numbers assigned by IANA at
      http://www.iana.org/assignments/protocol-numbers.

5.4.17. ipDiffServCodePoint

   Description:
      The value of a Differentiated Services Code Point (DSCP) encoded
      in the Differentiated Services field.  The Differentiated Services
      field spans the most significant 6 bits of the IPv4 TOS field or
      the IPv6 Traffic Class field, respectively.
      This Information Element encodes only the 6 bits of the
      Differentiated Services field.  Therefore, its value may range
      from 0 to 63.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 195
   Status: current
   Range: The valid range is 0-63.
   Reference:
      See RFC 3260 for the definition of the Differentiated Services
      field.  See RFC 1812 (Section 5.3.2) and RFC 791 for the
      definition of the IPv4 TOS field.  See RFC 2460 for the definition
      of the IPv6 Traffic Class field.

5.4.18. ipPrecedence

   Description:
      The value of the IP Precedence.  The IP Precedence value is
      encoded in the first 3 bits of the IPv4 TOS field or the IPv6
      Traffic Class field, respectively.  This Information Element
      encodes only these 3 bits.  Therefore, its value may range from 0
      to 7.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 196
   Status: current

   Range: The valid range is 0-7.
   Reference:
      See RFC 1812 (Section 5.3.3) and RFC 791 for the definition of the
      IP Precedence.  See RFC 1812 (Section 5.3.2) and RFC 791 for the
      definition of the IPv4 TOS field.  See RFC 2460 for the definition
      of the IPv6 Traffic Class field.

5.4.19. ipClassOfService

   Description:
      For IPv4 packets, this is the value of the TOS field in the IPv4
      packet header.  For IPv6 packets, this is the value of the Traffic
      Class field in the IPv6 packet header.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 5
   Status: current
   Reference:
      See RFC 1812 (Section 5.3.2) and RFC 791 for the definition of the
      IPv4 TOS field.  See RFC 2460 for the definition of the IPv6
      Traffic Class field.

5.4.20. postIpClassOfService

   Description:
      The definition of this Information Element is identical to the
      definition of Information Element 'ipClassOfService', except that
      it reports a potentially modified value caused by a middlebox
      function after the packet passed the Observation Point.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 55
   Status: current
   Reference:
      See RFC 791 for the definition of the IPv4 TOS field.  See RFC
      2460 for the definition of the IPv6 Traffic Class field.  See RFC
      3234 for the definition of middleboxes.

5.4.21. flowLabelIPv6

   Description:
      The value of the IPv6 Flow Label field in the IP packet header.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 31
   Status: current
   Reference:
      See RFC 2460 for the definition of the Flow Label field in the
      IPv6 packet header.

5.4.22. isMulticast

   Description:
      If the IP destination address is not a reserved multicast address,
      then the value of all bits of the octet (including the reserved
      ones) is zero.
      The first bit of this octet is set to 1 if the Version field of
      the IP header has the value 4 and if the Destination Address field
      contains a reserved multicast address in the range from 224.0.0.0
      to 239.255.255.255.  Otherwise, this bit is set to 0.  The second
      and third bits of this octet are reserved for future use.
      The remaining bits of the octet are only set to values other than
      zero if the IP Destination Address is a reserved IPv6 multicast
      address.  Then the fourth bit of the octet is set to the value of
      the T flag in the IPv6 multicast address and the remaining four
      bits are set to the value of the scope field in the IPv6 multicast
      address.

            0      1      2      3      4      5      6      7
         +------+------+------+------+------+------+------+------+
         | MCv4 | RES. | RES. |  T   |   IPv6 multicast scope    |
         +------+------+------+------+------+------+------+------+

         Bit  0:    set to 1 if IPv4 multicast
         Bits 1-2:  reserved for future use
         Bit  4:    set to value of T flag, if IPv6 multicast
         Bits 4-7:  set to value of multicast scope if IPv6 multicast

   Abstract Data Type: unsigned8
   Data Type Semantics: flags
   ElementId: 206
   Status: current

   Reference:
      See RFC 1112 for the specification of reserved IPv4 multicast
      addresses.  See RFC 4291 for the specification of reserved IPv6
      multicast addresses and the definition of the T flag and the IPv6
      multicast scope.

5.4.23. fragmentIdentification

   Description:
      The value of the Identification field in the IPv4 packet header or
      in the IPv6 Fragment header, respectively.  The value is 0 for
      IPv6 if there is no fragment header.
   Abstract Data Type: unsigned32
   Data Type Semantics: identifier
   ElementId: 54
   Status: current
   Reference:
      See RFC 791 for the definition of the IPv4 Identification field.
      See RFC 2460 for the definition of the Identification field in the
      IPv6 Fragment header.

5.4.24. fragmentOffset

   Description:
      The value of the IP fragment offset field in the IPv4 packet
      header or the IPv6 Fragment header, respectively.  The value is 0
      for IPv6 if there is no fragment header.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 88
   Status: current
   Reference:
      See RFC 791 for the specification of the fragment offset in the
      IPv4 header.  See RFC 2460 for the specification of the fragment
      offset in the IPv6 Fragment header.

5.4.25. fragmentFlags

   Description:
      Fragmentation properties indicated by flags in the IPv4 packet
      header or the IPv6 Fragment header, respectively.

      Bit 0:    (RS) Reserved.
                The value of this bit MUST be 0 until specified
                otherwise.

      Bit 1:    (DF) 0 = May Fragment,  1 = Don't Fragment.
                Corresponds to the value of the DF flag in the
                IPv4 header.  Will always be 0 for IPv6 unless
                a "don't fragment" feature is introduced to IPv6.

      Bit 2:    (MF) 0 = Last Fragment, 1 = More Fragments.
                Corresponds to the MF flag in the IPv4 header
                or to the M flag in the IPv6 Fragment header,
                respectively.  The value is 0 for IPv6 if there
                is no fragment header.

      Bits 3-7: (DC) Don't Care.
                The values of these bits are irrelevant.

           0   1   2   3   4   5   6   7
         +---+---+---+---+---+---+---+---+
         | R | D | M | D | D | D | D | D |
         | S | F | F | C | C | C | C | C |
         +---+---+---+---+---+---+---+---+

   Abstract Data Type: unsigned8
   Data Type Semantics: flags
   ElementId: 197
   Status: current
   Reference:
      See RFC 791 for the specification of the IPv4 fragment flags.  See
      RFC 2460 for the specification of the IPv6 Fragment header.

5.4.26. ipHeaderLength

   Description:
      The length of the IP header.  For IPv6, the value of this
      Information Element is 40.
   Abstract Data Type: unsigned8
   ElementId: 189
   Status: current
   Units: octets
   Reference:
      See RFC 791 for the specification of the IPv4 header.  See RFC
      2460 for the specification of the IPv6 header.

5.4.27. ipv4IHL

Description: The value of the Internet Header Length (IHL) field in the IPv4 header. It specifies the length of the header in units of 4 octets. Please note that its unit is different from most of the other Information Elements reporting length values.

   Abstract Data Type: unsigned8
   ElementId: 207
   Status: current
   Units: 4 octets
   Reference:
      See RFC 791 for the specification of the IPv4 header.

5.4.28. totalLengthIPv4

   Description:
      The total length of the IPv4 packet.
   Abstract Data Type: unsigned16
   ElementId: 190
   Status: current
   Units: octets
   Reference:
      See RFC 791 for the specification of the IPv4 total length.

5.4.29. ipTotalLength

   Description:
      The total length of the IP packet.
   Abstract Data Type: unsigned64
   ElementId: 224
   Status: current
   Units: octets
   Reference:
      See RFC 791 for the specification of the IPv4 total length.  See
      RFC 2460 for the specification of the IPv6 payload length.  See
      RFC 2675 for the specification of the IPv6 jumbo payload length.

5.4.30. payloadLengthIPv6

Description: This Information Element reports the value of the Payload Length field in the IPv6 header. Note that IPv6 extension headers belong to the payload. Also note that in case of a jumbo payload option the value of the Payload Length field in the IPv6 header is zero and so will be the value reported by this Information Element. Abstract Data Type: unsigned16 ElementId: 191 Status: current Units: octets Reference: See RFC 2460 for the specification of the IPv6 payload length. See RFC 2675 for the specification of the IPv6 jumbo payload option.

5.5. Transport Header Fields

The set of Information Elements related to transport header fields and length includes the Information Elements listed in the table below.

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   |   7 | sourceTransportPort       | 238 | tcpWindowScale            |
   |  11 | destinationTransportPort  | 187 | tcpUrgentPointer          |
   | 180 | udpSourcePort             | 188 | tcpHeaderLength           |
   | 181 | udpDestinationPort        |  32 | icmpTypeCodeIPv4          |
   | 205 | udpMessageLength          | 176 | icmpTypeIPv4              |
   | 182 | tcpSourcePort             | 177 | icmpCodeIPv4              |
   | 183 | tcpDestinationPort        | 139 | icmpTypeCodeIPv6          |
   | 184 | tcpSequenceNumber         | 178 | icmpTypeIPv6              |
   | 185 | tcpAcknowledgementNumber  | 179 | icmpCodeIPv6              |
   | 186 | tcpWindowSize             |  33 | igmpType                  |
   +-----+---------------------------+-----+---------------------------+

5.5.1. sourceTransportPort

   Description:
      The source port identifier in the transport header.  For the
      transport protocols UDP, TCP, and SCTP, this is the source port
      number given in the respective header.  This field MAY also be
      used for future transport protocols that have 16-bit source port
      identifiers.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 7
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP source port field.  See
      RFC 793 for the definition of the TCP source port field.  See RFC
      4960 for the definition of SCTP.
      Additional information on defined UDP and TCP port numbers can be
      found at http://www.iana.org/assignments/port-numbers.

5.5.2. destinationTransportPort

   Description:
      The destination port identifier in the transport header.  For the
      transport protocols UDP, TCP, and SCTP, this is the destination
      port number given in the respective header.  This field MAY also
      be used for future transport protocols that have 16-bit
      destination port identifiers.

   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 11
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP destination port field.
      See RFC 793 for the definition of the TCP destination port field.
      See RFC 4960 for the definition of SCTP.  Additional information
      on defined UDP and TCP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.5.3. udpSourcePort

   Description:
      The source port identifier in the UDP header.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 180
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP source port field.
      Additional information on defined UDP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.5.4. udpDestinationPort

   Description:
      The destination port identifier in the UDP header.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 181
   Status: current
   Reference:
      See RFC 768 for the definition of the UDP destination port field.
      Additional information on defined UDP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.5.5. udpMessageLength

   Description:
      The value of the Length field in the UDP header.
   Abstract Data Type: unsigned16
   ElementId: 205
   Status: current
   Units: octets
   Reference:
      See RFC 768 for the specification of the UDP header.

5.5.6. tcpSourcePort

   Description:
      The source port identifier in the TCP header.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 182
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP source port field.
      Additional information on defined TCP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.5.7. tcpDestinationPort

   Description:
      The destination port identifier in the TCP header.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 183
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP source port field.
      Additional information on defined TCP port numbers can be found at
      http://www.iana.org/assignments/port-numbers.

5.5.8. tcpSequenceNumber

   Description:
      The sequence number in the TCP header.
   Abstract Data Type: unsigned32
   ElementId: 184
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP sequence number.

5.5.9. tcpAcknowledgementNumber

   Description:
      The acknowledgement number in the TCP header.
   Abstract Data Type: unsigned32
   ElementId: 185
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP acknowledgement number.

5.5.10. tcpWindowSize

   Description:
      The window field in the TCP header.  If the TCP window scale is
      supported, then TCP window scale must be known to fully interpret
      the value of this information.
   Abstract Data Type: unsigned16
   ElementId: 186
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP window field.  See RFC
      1323 for the definition of the TCP window scale.

5.5.11. tcpWindowScale

   Description:
      The scale of the window field in the TCP header.
   Abstract Data Type: unsigned16
   ElementId: 238
   Status: current
   Reference:
      See RFC 1323 for the definition of the TCP window scale.

5.5.12. tcpUrgentPointer

   Description:
      The urgent pointer in the TCP header.
   Abstract Data Type: unsigned16
   ElementId: 187
   Status: current
   Reference:
      See RFC 793 for the definition of the TCP urgent pointer.

5.5.13. tcpHeaderLength

   Description:
      The length of the TCP header.  Note that the value of this
      Information Element is different from the value of the Data Offset
      field in the TCP header.  The Data Offset field indicates the
      length of the TCP header in units of 4 octets.  This Information
      Elements specifies the length of the TCP header in units of
      octets.
   Abstract Data Type: unsigned8
   ElementId: 188
   Status: current
   Units: octets
   Reference:
      See RFC 793 for the definition of the TCP header.

5.5.14. icmpTypeCodeIPv4

   Description:
      Type and Code of the IPv4 ICMP message.  The combination of both
      values is reported as (ICMP type * 256) + ICMP code.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 32
   Status: current
   Reference:
      See RFC 792 for the definition of the IPv4 ICMP type and code
      fields.

5.5.15. icmpTypeIPv4

   Description:
      Type of the IPv4 ICMP message.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 176
   Status: current
   Reference:
      See RFC 792 for the definition of the IPv4 ICMP type field.

5.5.16. icmpCodeIPv4

   Description:
      Code of the IPv4 ICMP message.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 177
   Status: current
   Reference:
      See RFC 792 for the definition of the IPv4 ICMP code field.

5.5.17. icmpTypeCodeIPv6

   Description:
      Type and Code of the IPv6 ICMP message.  The combination of both
      values is reported as (ICMP type * 256) + ICMP code.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 139
   Status: current
   Reference:
      See RFC 4443 for the definition of the IPv6 ICMP type and code
      fields.

5.5.18. icmpTypeIPv6

   Description:
      Type of the IPv6 ICMP message.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 178
   Status: current
   Reference:
      See RFC 4443 for the definition of the IPv6 ICMP type field.

5.5.19. icmpCodeIPv6

   Description:
      Code of the IPv6 ICMP message.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 179
   Status: current
   Reference:
      See RFC 4443 for the definition of the IPv6 ICMP code field.

5.5.20. igmpType

   Description:
      The type field of the IGMP message.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 33
   Status: current
   Reference:
      See RFC 3376 for the definition of the IGMP type field.

5.6. Sub-IP Header Fields

The set of Information Elements related to Sub-IP header fields includes the Information Elements listed in the table below.

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   |  56 | sourceMacAddress          | 201 | mplsLabelStackLength      |
   |  81 | postSourceMacAddress      | 194 | mplsPayloadLength         |
   |  58 | vlanId                    |  70 | mplsTopLabelStackSection  |
   |  59 | postVlanId                |  71 | mplsLabelStackSection2    |
   |  80 | destinationMacAddress     |  72 | mplsLabelStackSection3    |
   |  57 | postDestinationMacAddress |  73 | mplsLabelStackSection4    |
   | 146 | wlanChannelId             |  74 | mplsLabelStackSection5    |
   | 147 | wlanSSID                  |  75 | mplsLabelStackSection6    |
   | 200 | mplsTopLabelTTL           |  76 | mplsLabelStackSection7    |
   | 203 | mplsTopLabelExp           |  77 | mplsLabelStackSection8    |
   | 237 | postMplsTopLabelExp       |  78 | mplsLabelStackSection9    |
   | 202 | mplsLabelStackDepth       |  79 | mplsLabelStackSection10   |
   +-----+---------------------------+-----+---------------------------+

5.6.1. sourceMacAddress

   Description:
      The IEEE 802 source MAC address field.
   Abstract Data Type: macAddress
   Data Type Semantics: identifier
   ElementId: 56
   Status: current
   Reference:
      See IEEE.802-3.2002.

5.6.2. postSourceMacAddress

   Description:
      The definition of this Information Element is identical to the
      definition of Information Element 'sourceMacAddress', except that
      it reports a potentially modified value caused by a middlebox
      function after the packet passed the Observation Point.
   Abstract Data Type: macAddress
   Data Type Semantics: identifier
   ElementId: 81
   Status: current
   Reference:
      See IEEE.802-3.2002.

5.6.3. vlanId

   Description:
      The IEEE 802.1Q VLAN identifier (VID) extracted from the Tag
      Control Information field that was attached to the IP packet.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 58
   Status: current
   Reference:
      See IEEE.802-1Q.2003.

5.6.4. postVlanId

   Description:
      The definition of this Information Element is identical to the
      definition of Information Element 'vlanId', except that it reports
      a potentially modified value caused by a middlebox function after
      the packet passed the Observation Point.
   Abstract Data Type: unsigned16
   Data Type Semantics: identifier
   ElementId: 59
   Status: current
   Reference:
      See IEEE.802-1Q.2003.

5.6.5. destinationMacAddress

   Description:
      The IEEE 802 destination MAC address field.
   Abstract Data Type: macAddress
   Data Type Semantics: identifier
   ElementId: 80
   Status: current
   Reference:
      See IEEE.802-3.2002.

5.6.6. postDestinationMacAddress

   Description:
      The definition of this Information Element is identical to the
      definition of Information Element 'destinationMacAddress', except
      that it reports a potentially modified value caused by a middlebox
      function after the packet passed the Observation Point.
   Abstract Data Type: macAddress
   Data Type Semantics: identifier
   ElementId: 57
   Status: current

   Reference:
      See IEEE.802-3.2002.

5.6.7. wlanChannelId

   Description:
      The identifier of the 802.11 (Wi-Fi) channel used.
   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 146
   Status: current
   Reference:
      See IEEE.802-11.1999.

5.6.8. wlanSSID

   Description:
      The Service Set IDentifier (SSID) identifying an 802.11 (Wi-Fi)
      network used.  According to IEEE.802-11.1999, the SSID is encoded
      into a string of up to 32 characters.
   Abstract Data Type: string
   ElementId: 147
   Status: current
   Reference:
      See IEEE.802-11.1999.

5.6.9. mplsTopLabelTTL

   Description:
      The TTL field from the top MPLS label stack entry, i.e., the last
      label that was pushed.
   Abstract Data Type: unsigned8
   ElementId: 200
   Status: current
   Units: hops
   Reference:
      See RFC 3032 for the specification of the TTL field.

5.6.10. mplsTopLabelExp

   Description:
      The Exp field from the top MPLS label stack entry, i.e., the last
      label that was pushed.

      Bits 0-4:  Don't Care, value is irrelevant.
      Bits 5-7:  MPLS Exp field.

          0   1   2   3   4   5   6   7
        +---+---+---+---+---+---+---+---+
        |     don't care    |    Exp    |
        +---+---+---+---+---+---+---+---+

   Abstract Data Type: unsigned8
   Data Type Semantics: flags
   ElementId: 203
   Status: current
   Reference:
      See RFC 3032 for the specification of the Exp field.  See RFC 3270
      for usage of the Exp field.

5.6.11. postMplsTopLabelExp

   Description:
      The definition of this Information Element is identical to the
      definition of Information Element 'mplsTopLabelExp', except that
      it reports a potentially modified value caused by a middlebox
      function after the packet passed the Observation Point.
   Abstract Data Type: unsigned8
   Data Type Semantics: flags
   ElementId: 237
   Status: current
   Reference:
      See RFC 3032 for the specification of the Exp field.  See RFC 3270
      for usage of the Exp field.

5.6.12. mplsLabelStackDepth

   Description:
      The number of labels in the MPLS label stack.
   Abstract Data Type: unsigned32
   ElementId: 202
   Status: current
   Units: label stack entries
   Reference:
      See RFC 3032 for the specification of the MPLS label stack.

5.6.13. mplsLabelStackLength

   Description:
      The length of the MPLS label stack in units of octets.
   Abstract Data Type: unsigned32
   ElementId: 201
   Status: current
   Units: octets
   Reference:
      See RFC 3032 for the specification of the MPLS label stack.

5.6.14. mplsPayloadLength

   Description:
      The size of the MPLS packet without the label stack.
   Abstract Data Type: unsigned32
   ElementId: 194
   Status: current
   Units: octets
   Reference:
      See RFC 3031 for the specification of MPLS packets.  See RFC 3032
      for the specification of the MPLS label stack.

5.6.15. mplsTopLabelStackSection

   Description:
      The Label, Exp, and S fields from the top MPLS label stack entry,
      i.e., from the last label that was pushed.  The size of this