Internet Draft                                              Tanja Zseby
 Document: <draft-ietf-ipfix-as-11.txt>                 Fraunhofer FOKUS
 Expires: July 2007                                         Elisa Boschi
                                                          Nevil Brownlee
                                                           Benoit Claise
                                                           Cisco Systems
                                                           February 2007
                           IPFIX Applicability
    Status of this Memo
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                      IPFIX Applicability              August 2006
    This document describes the applicability of the IP Flow
    Information Export (IPFIX) protocol for a variety of
    applications. It shows how applications can use IPFIX, describes
    the relevant information elements (IEs) and shows opportunities
    and limitations of the protocol. The document furthermore
    describes relations of the IPFIX framework to other
    architectures and frameworks.
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 Table of Contents
    1.   Introduction.............................................4
    2.   Applications of IPFIX....................................4
    2.1  Accounting...............................................4
    2.1.1 Example.................................................5
    2.2  Traffic Profiling........................................7
    2.3  Traffic Engineering......................................8
    2.4  Network Security.........................................9
    2.5  QoS Monitoring..........................................11
    2.5.1 Correlating Events from Multiple Observation Points....11
    2.5.2 Examples...............................................12
    2.6  Inter-Domain Exchange of IPFIX data.....................14
    2.7  Export of Derived Metrics...............................14
    2.8  Summary.................................................15
    3.   Relation of IPFIX to Other Frameworks and Protocols.....15
    3.1  IPFIX and IPv6..........................................16
    3.2  IPFIX and PSAMP.........................................16
    3.3  IPFIX and RMON..........................................16
    3.4  IPFIX and IPPM..........................................18
    3.5  IPFIX and AAA...........................................18
    3.5.1 Connecting via an AAA Client...........................19
    3.5.2 Connecting via an Application Specific Module (ASM)....20
    3.6  IPFIX and RTFM..........................................21
    3.6.1 Architecture...........................................21
    3.6.2 Flow Definition........................................21
    3.6.3 Configuration and Management...........................22
    3.6.4 Data Collection........................................22
    3.6.5 Data Model Details.....................................22
    3.6.6 Transport Protocol.....................................23
    3.6.7 Summary................................................23
    4.   Limitations.............................................23
    4.1  Using IPFIX for other Applications than Listed in RFC391724
    4.2  Using IPFIX for Billing (Reliability Limitations).......24
    4.3  Using a Different Transport Protocol than SCTP..........25
    4.4  Push vs. Pull Mode......................................25
    4.5  Template ID number......................................26
    4.6  Exporting Bidirectional Flow Information................26
    4.7  Remote Configuration....................................26
    5.   Security Considerations.................................27
    6.   IANA Considerations.....................................27
    7.   Normative References....................................27
    8.   Informative References..................................28
    9.   Acknowledgements........................................30
    10.  Authors' Addresses......................................30
    11.  Full Copyright Statement................................31
    12.  Disclaimer..............................................31
    13.  Intellectual Property Statement.........................31
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 1. Introduction
    The IPFIX protocol defines how IP Flow information can be
    exported from routers, measurement probes or other devices. IP
    flow information can be used as input to various applications.
    IPFIX is a general data transport protocol, easily extensible to
    suit the needs of different applications. This document
    describes how typical applications can use the IPFIX protocol.
    It shows opportunities and limitations of the protocol.
    Furthermore, the relationship of IPFIX to other frameworks and
    architectures is described. Although examples in this document
    are shown for IPv4 only, the applicability statements apply to
    IPv4 and IPv6. IPFIX provides appropriate Information Elements
    for both IP versions.
 2. Applications of IPFIX
    IPFIX data enables several critical applications. The IPFIX
    target applications and the requirements that originate from
    those applications are described in [RFC3917]. Those
    requirements were used as basis for the design of the IPFIX
    protocol. This section describes how these target applications
    can use the IPFIX protocol. Considerations for using IPFIX for
    other applications than described in [RFC3917] can be found in
    section 4.1.
  2.1 Accounting
    Usage-based accounting is one of the target applications for
    IPFIX as defined in [RFC3917]. IPFIX records provide fine-
    grained measurement results for highly flexible and detailed
    usage reporting. Such data is often used to realize usage-based
    accounting. Nevertheless, IPFIX does not provide the reliability
    required by usage-based billing-systems as defined in [RFC2975]
    (see section 4.2). The accounting scenarios described in this
    document only provide limited reliability as explained in
    section 4.2 and should not be used in environments where
    reliability as demanded by [RFC2975] is mandatory.
    In order to realize usage-based accounting with IPFIX the flow
    definition has to be chosen in accordance to the tariff model.
    Flows can be distinguished by various IEs (e.g. packet header
    fields) from [IPFIX-INFO]. Due to the flexible IPFIX flow
    definition, arbitrary flow-based accounting models can be
    realized without extensions to the IPFIX protocol.
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    A tariff can, for instance, be based on individual end-to-end
    flows, in which case accounting can be realized with a flow
    definition determined by the quintuple consisting of source
    address (sourceIPv4Address), destination address
    (destinationIPv4Address), protocol (protocolIdentifier) and port
    numbers (e.g., udpSourcePort, udpDestinationPort). Another
    example is a class-dependent tariff (e.g. in a DiffServ
    network). In this case flows could be distinguished just by the
    DiffServ codepoint (DSCP) (ipDiffServCodePoint) and IP addresses
    (sourceIPv4Address, destinationIPv4Address). The essential
    elements needed for accounting are the number of transferred
    packets and bytes per flow, which can be represented by the per-
    flow counter IEs (e.g., packetTotalCount, octetTotalCount).
    For accounting purposes, it would be advantageous to have the
    ability to use IPFIX flow records as accounting input in an AAA
    infrastructure. AAA servers then could provide the mapping
    between user and flow information. Again for such scenarios the
    limited reliability currently provided by IPFIX has to be taken
    into account.
 2.1.1 Example
    Please note: As noted in [RFC3330] the address block may be used for example addresses. In the example
    below we use two example networks. In order to be conformant to
    [RFC3330] we divide the given address block into two networks by
    subnetting with a 25 bit netmask ( as follows:
    Network A: ...
    Network B: ...
    Let's suppose someone has a Service Level Agreement (SLA) in a
    DiffServ network requiring accounting based on traffic volume.
    Flows are distinguished by source and destination address. The
    information to export in this case is:
        - IPv4 source IP address: sourceIPv4Address in [IPFIX-INFO],
         with a length of 4 octets
        - IPv4 destination IP address: destinationIPv4Address in
         [IPFIX-INFO], with a length of 4 octets
        - DSCP: ipDiffServCodePoint in [IPFIX-INFO], with a length of
         1 octet
        - Number of octets of the Flow: octetDeltaCount in [IPFIX-
         INFO], with a length of 4 octets
    The template set will look as follows:
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      |         Set ID = 2            |      Length = 24 octets       |
      |       Template ID 256         |       Field Count = 4         |
      |0|    sourceIPv4Address = 8    |       Field Length = 4        |
      |0| destinationIPv4Address = 12 |       Field Length = 4        |
      |0|  ipDiffServCodePoint = 195  |       Field Length = 1        |
      |0|     octetDeltaCount = 1     |       Field Length = 4        |
    The information to be exported might be as listed in the
    following example table:
    Src. IP addr. | Dst. IP addr. |  DSCP  | Octets Number
    --------------+---------------+--------+--------------    |  |   46   |   120868    |  |   46   |   310364    |  |   46   |   241239
    In the example we use Diffserv CodePoint 46, recommended for the
    Expedited Forwarding Per Hop Behavior (EF PHB) in [RFC3246].
    The Flow Records will then look as follows:
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     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    |          Set ID = 256         |          Length = 43          |
    |                                           |
    |                                          |
    |      46       |               120868                          |
    |               |                           |
    |               |                          |
    |               |       46      |                 310364        |
    |                               |            |
    |                               |           |
    |                               |       46      |               |
    |                   241239                      |
  2.2 Traffic Profiling
    Measurement results reported in IPFIX records can be used for
    traffic profiling. IPFIX records captured over a long period of
    time can be used to track and anticipate network growth and
    usage. Such Information is valuable for trend analysis and
    network planning.
    The parameters of interest are determined by the profiling
    objectives. Example parameters for traffic profiling are flow
    duration, flow volume, burstiness, the distribution of used
    services and protocols, the amount of packets of a specific
    type, etc. [RFC3917].
    The distribution of services and protocols in use can be
    analyzed by configuring appropriate flows keys for flow
    discrimination. Protocols can be distinguished by the
    protocolIdentifier IE. Portnumbers (e.g., udpDestinationPort)
    often provide information about services in use. Those flow keys
    are defined in [IPFIX-INFO]. If portnumbers are not sufficient
    for service discrimination, further parts of the packet may be
    needed. Header fields can be expressed by IEs from [IPFIX-INFO].
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    Packet payload can be reported by using the IE
    ipPayloadPacketSection in [PSAMP-INFO].
    The flow duration can be calculated from the flow time stamp IEs
    defined in [IPFIX-INFO] (e.g., flowEndMicroseconds -
    flowStartMicroseconds). The number of packets and number of
    bytes of a flow are represented in the per-flow counter IEs
    (e.g., packetTotalCount, octetTotalCount). The burstiness of a
    flow can be calculated from the flow volume measured at
    different time intervals.
  2.3 Traffic Engineering
    Traffic engineering aims at the optimization of network resource
    utilization and traffic performance [RFC2702]. Typical
    parameters are link utilization, load between specific network,
    nodes, number, size and entry/exit points of active flows and
    routing information [RFC3917].
    The size of flows in packets and bytes can be reported by IEs
    packetTotalCount, octetTotalCount. Physical link utilization can
    be reported by using a coarse grained flow definition (e.g.
    based on identifier IEs such as egressInterface or
    ingressInterface) and per-flow counter IEs (e.g.
    packetTotalCount, octetTotalCount) defined in [IPFIX-INFO].
    The load between specific network nodes can be reported in the
    same way if one interface of a network node receives only
    traffic from exactly one neighbor node (as is usually the case).
    If the ingress interface is not sufficient for an unambiguous
    identification of the neighbor node, sub-IP header fields IEs
    (like sourceMacAddress) can be added as flow keys.
    The IE observedFlowTotalCount provides the number of all flows
    exported for the observation domain since the last
    initialization of the metering process [IPFIX-INFO]. If this IE
    is exported at subsequent points in time, one can derive the
    number of active flows in a specific time interval from the
    difference of the reported counters. The configured flow
    termination criteria have to be taken into account to interpret
    those numbers correctly.
    Entry and exit points can be derived from flow records if
    metering processes are installed at all edges of the network and
    results are mapped in accordance to flow keys. For this and
    other analysis methods that require the mapping of records from
    different observation points, the same flow keys should be used
    at all observation points. The path that packets take through a
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    network can be investigated by using hash-based sampling
    techniques as described in [DuGr00] and [PSAMP-TECH]. For this
    IEs from [PSAMP-INFO] are needed.
    Neither [IPFIX-INFO] nor [PSAMP-INFO] defines IEs suitable for
    exporting routing information.
  2.4 Network Security
    Attack and intrusion detection are among the IPFIX target
    applications described in [RFC3917]. Due to the enormous amount
    of different network attack types, only general requirements
    could be addressed in [RFC3917].
    The number of metrics useful for attack detection is as diverse
    as attack patterns themselves. Attackers adapt rapidly to
    circumvent detection methods and try to hide attack patterns
    using slow or stealth attacks. Furthermore, unusual traffic
    patterns are not always caused by malicious activities. A sudden
    traffic increase may be caused by legitimate users who seek
    access to a recently published web content. Strange traffic
    patterns may also be caused by mis-configuration.
    IPFIX can export flow information for arbitrary flow definitions
    as defined in [IPFIX-PROTO]. Packet information can be exported
    with IPFIX by using the additional information elements
    described in [PSAMP-INFO]. With this theoretically all
    information about traffic in the network at IP layer and above
    is accessible. This data can be used either directly to detect
    anomalies or can provide the basis for further post processing
    to generate more complex attack detection metrics.
    Depending on the attack type different metrics are useful. A
    sudden increase of traffic load can be a hint that an attack has
    been launched. The overall traffic at an observation point can
    be monitored using per-flow counter IEs like packetTotalCount,
    octetTotalCount as described in 2.3. The number of active flows
    can be monitored by regular reporting of the
    observedFlowTotalCount defined in [IPFIX-INFO].
    A sudden increase of flows from different sources to one
    destination may be caused by an attack on a specific host or
    network node using spoofed addresses. The number of flows from
    or to specific networks or hosts can be observed by using source
    and destination addresses as flow keys and observing the number
    of active flows as explained above.
    Many flows to the same machine but on different ports or many
    flows to the same port and different machines may be an
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    indicator for vertical or horizontal port scanning activities.
    The number of flows to different ports can be reported by using
    the portnumber information elements (udpSourcePort,
    udpDestinationPort, tcpSourcePort, tcpDestinationPort) defined
    in [IPFIX-INFO] as flow keys.
    An unusual ratio of TCP-SYN to TCP-FIN packets can refer to SYN-
    flooding. The number of SYN and FIN packets in a flow can be
    reported with the IPFIX information elements tcpSynTotalCount
    and tcpFinTotalCount defined in [IPFIX-INFO].
    Worms may leave signatures in traffic patterns. Detecting such
    events requires more detailed measurements and post processing
    than detecting simple changes in traffic volumes.
    A difficult task is the separation of good from bad packets to
    prepare and launch counteraction. This may require a deeper look
    into packet content by using further header field IEs from
    [IPFIX-INFO] and/or packet payload from IE
    ipPayloadPacketSection in [PSAMP-INFO].
    Furthermore the amount of resources needed for measurement and
    reporting increases with the level of granularity required to
    detect an attack. Multi-step analysis techniques may be useful,
    e.g., to launch an in-depth analysis (e.g. based on packet
    information) in case the flow information shows suspicious
    patterns. In order to supervise traffic to a specific host or
    network node it is useful to apply filtering methods as those
    described in [PSAMP-TECH].
    Mapping the two directions of a communication is often useful
    for checking correct protocol behavior (see section 4.6). A
    correlation of IPFIX data from multiple observation points (see
    section 2.5.1) allows assessing the propagation of an attack and
    can help to locate its source.
    The integration of previous measurement results helps to review
    traffic changes over time for detection of traffic anomalies and
    provides the basis for forensic analysis. A standardized storage
    format for IPFIX data would support the offline analysis of data
    from different operators.
    Nevertheless, capturing full packet traces at all observation
    points in the network is not viable due to resource limitations
    and privacy concerns. Therefore metrics should be chosen wisely
    to allow a solid detection with minimal resource consumption.
    Resources can be saved for instance by using coarser grained
    flow definitions, reporting pre-processed metrics (e.g. with
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    additional information elements) or deployment of sampling
    Detecting security incidents in real-time often requires the
    pre-processing of data already at the measurement device. That
    means that measured data need to be processed already in the
    measurement device in order to generate useful metrics for
    detecting an attack as early as possible. Immediate data export
    in case of a potential incident is desired. IPFIX supports such
    source-triggered exporting of information due to the push model
    approach. Nevertheless, further exporting criteria have to be
    implemented to export IPFIX records upon incident detection
    events and not only upon flow end or fixed time intervals.
    Intrusion detection would profit from the combination of IPFIX
    functions with AAA functions (see section 3.5). Such an
    interoperation enables further means for attacker detection,
    advanced defense strategies and secure inter-domain cooperation.
  2.5 QoS Monitoring
    QoS monitoring is one target application of the IPFIX protocol
    [RFC3917]. QoS monitoring is the passive observation of the
    transmission quality for single flows or traffic aggregates in
    the network. One example of its use is the validation of QoS
    guarantees in service level agreements (SLAs). Typical QoS
    parameters are loss [RFC2680], one-way [RFC2679] and round-trip
    delay [RFC2681] and delay variation [RFC3393]. Whenever
    applicable the metric definitions of the IPPM group should be
    used when reporting QoS Metrics.
    The calculation of those QoS metrics requires per-packet
    processing. Reporting packet information with IPFIX is possible
    by simply considering a single packet as flow. [IPFIX-PROTO]
    also allows the reporting of multiple identical information
    elements in one flow record. Using this feature for reporting
    information about multiple packets in one record would require
    additional agreement on semantics regarding the order of
    information elements (e.g. which timestamp belongs to which
    packet payload in a sequence of information elements). [PSAMP-
    INFO] defines useful additional information elements for
    exporting per packet information with IPFIX.
 2.5.1 Correlating Events from Multiple Observation Points
    Some QoS metrics require the correlation of data from multiple
    observation points. For this the clocks of the involved metering
    processes must be synchronized. Furthermore, it is necessary to
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    recognize that the same packet was observed at different
    observation point.
    This can be done by capturing parts of the packet content
    (packet header and/or parts of the payload) that do not change
    on the way to the destination. Based on the packet content it
    can be recognized when the same packet arrived at another
    observation point. To reduce the amount of measurement data a
    unique packet ID can be calculated from the packet content e.g.
    by using a CRC or hash function instead of transferring and
    comparing the unprocessed content. Considerations on collision
    probability and efficiency of using such packet IDs are
    described in [GrDM98, DuGr00, ZsZC01].
    IPFIX allows the reporting of several IP and transport header
    fields (see section 5.3 and 5.4 in [IPFIX-INFO]). Using only
    those fields for packet recognition or ID generation can be
    sufficient in scenarios where those header fields vary a lot
    among subsequent packets, where a certain amount of packet ID
    collisions are tolerable or where packet IDs need to be unique
    only for a small time interval.
    For including packet payload information the information element
    ipPayloadPacketSection defined in [PSAMP-INFO] can be used. The
    information element ipHeaderPacketSection can also be used. But
    header fields that can change on the way from source to
    destination have to be excluded from the packet ID generation,
    because they may differ at different observation points.
    For reporting packet IDs generated by a CRC or hash function the
    information element digestHashValue defined in [PSAMP-INFO] can
    be used.
 2.5.2 Examples
    The following examples show which information elements need to
    be reported by IPFIX to generate specific QoS metrics. As an
    alternative the metrics can be generated directly at the
    exporter and IPFIX can be used to export the metrics (see
    section 2.7) RTT measurements with packet pair matching (single-point)
    The passive measurement of round-trip-times (RTT) can be
    performed by using packet pair matching techniques as described
    in [Brow00]. For the measurements, request/response packet pairs
    from protocols such as DNS, ICMP, SNMP or TCP (SYN/SYN_ACK,
    DATA/ACK) are utilized to passively observe the RTT [Brow00].
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    This technique requires the correlation of data from both
    Required information elements per packet (DNS example):
    - Packet arrival time: observationTimeMicroseconds [PSAMP-INFO]
    - DNS header: ipPayloadPacketSection [PSAMP-INFO]
    Required functions:
    - Recognition of request/response packet pairs
    - Requires information elements from [PSAMP-INFO]
    - observationTimeMicroseconds can be substituted by
       flowStartMicroseconds [IPFIX-INFO], because a single packet
       can be represented as a flow.
    - If time values with a finer granularity are needed
       observationTimeNanoseconds can be used. One-way Delay Measurements (multi-point)
    Passive one-way-delay measurements require the collection of
    data at two observation points. As mentioned above synchronized
    clocks are needed to avoid time-differences at the involved
    observation points.
    The recognition of packets at the second observation point can
    be based on parts of the packet content directly. A more
    efficient way is to use a packet ID (generated from packet
    Required information elements per packet (with packet ID):
    - Packet arrival time: observationTimeMicroseconds [PSAMP-INFO]
    - Packet ID: digestHashValue [PSAMP-INFO]
    Required functions:
    - packet ID generation
    - delay calculation (from arrival times at the two observation
    - Requires information elements from [PSAMP-INFO]
    - observationTimeMicroseconds can be substituted by
       flowStartMicroseconds [IPFIX-INFO], because a single packet
       can be represented as a flow.
    - If time values with a finer granularity are needed
       observationTimeNanoseconds can be used.
    - The amount of content used for ID generation influences the
       number of collisions (different packets that map to the same
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       ID) that can occur. Investigations on this and other
       considerations on packet ID generation can be found in
       [GrDM98], [DuGr00], and [ZsZC01].
  2.6 Inter-Domain Exchange of IPFIX data
    IPFIX data can be used to share information with neighbor
    providers. A few recommendations should be considered if IPFIX
    records travel over the public Internet compared to its usage
    within a single domain. First of all, security threat levels are
    higher if data travels over the public Internet. Protection
    against disclosure or manipulation of data is even more
    important than for intra-domain usage. Therefore IPsec or
    Transport Layer Security (TLS) should be used as described in
    Furthermore data transfer should be congestion-aware in order to
    allow untroubled co-existence with other data flows in public or
    foreign networks. That means transport over SCTP or TCP is
    Some ISPs are still reluctant to share information due to
    concerns that competing ISPs might exploit network information
    from neighbor providers to strengthen their own position in the
    market. Nevertheless, technical needs have already triggered the
    exchange of data in the past (e.g. exchange of routing
    information by BGP). The need to provide inter-domain guarantees
    is one big incentive to increase inter-domain cooperation. The
    necessity to defend networks against current and future threats
    (denial of service attacks, worm distributions, etc.) will
    hopefully increase the willingness to exchange measurement data
    between providers.
  2.7  Export of Derived Metrics
    The IPFIX protocol is used to transport flow and packet
    information to provide the input for the calculation of a
    variety of metrics (e.g. for QoS validation or attack
    IPFIX can also be used to transfer these metrics directly, e.g.
    if the metric calculation is co-located with measurement and
    exporting process.
    It doesn't matter which measurement and post-processing
    functions are applied to generate a specific metric. IPFIX can
    be used to transport the results from passive and active
    measurements and from post-processing operations. For the
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    reporting of derived metrics additional information elements
    need to be defined.
    For most QoS metrics like like loss, delay, delay variation etc.
    standard definitions exist from the IPPM group. In case such
    metrics are reported with IPIFX, the IPPM standard definition
    should be used.
  2.8 Summary
    The following table shows an overview of the information
    elements required for the target applications described in
    [RFC3917] (M-mandatory, R-recommended, O-optional).
    | Application |[IPFIX-INFO]| [PSAMP-INFO] | additional IEs  |
    | Accounting  |     M      |      -       |       -         |
    | Traffic     |     M      |      O       |       -         |
    | Profiling   |            |              |                 |
    | Traffic     |     M      |      -       |       O         |
    | Engineering |            |              | (routing info)  |
    | Attack      |     M      |      R       |       R         |
    | Detection   |            |              |(derived metrics)|
    | QoS         |     M      |      M       |       O         |
    | Monitoring  |            |(most metrics)|(derived metrics)|
    For accounting the IEs in [IPFIX-INFO] are sufficient. As
    mentioned above, IPFIX does not conform to the reliability
    requirements demanded by [RFC2975] for usage-based billing
    systems (see section 4.2).  For traffic profiling additionally
    IEs from [PSAMP-INFO] can be useful to gain more insight into
    the traffic. For traffic engineering flow information from
    [IPFIX-INFO] is sufficient but it would profit from routing
    information, which could be exported by IPFIX. Attack detection
    usually profits from further insight into the traffic. This can
    be achieved with IEs from [PSAMP-INFO]. Furthermore the
    reporting of derived metrics in additional IEs would be useful.
    Most QoS metrics require the use of IEs from [PSAMP-INFO]. IEs
    from [PSAMP-INFO] are also useful for the mapping of results
    from different observation points as described in section 2.5.1.
 3. Relation of IPFIX to Other Frameworks and Protocols
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  3.1 IPFIX and IPv6
    IPFIX has been designed from the beginning for IPv4 and IPv6.
    Therefore IPFIX can be used in IPv4 and IPv6 networks without
    limitations. The usage of IPFIX in IPv6 networks has two
    - Generation and reporting of IPFIX records about IPv6 traffic
    - Exporting IPFIX records over IPv6
    The generation and reporting of IPFIX records about IPv6 traffic
    is possible. Appropriate information elements for the reporting
    of IPv6 traffic are defined in [IPFIX-INFO].
    Exporting IPFIX records over IPv6 is not explicitly addressed in
    [IPFIX-PROTO]. Since IPFIX runs over a transport protocol (SCTP,
    SCTP-PR, UDP or TCP) and all potential IPFIX transport protocols
    can run in IPv6 networks one just needs to provide the chosen
    transport protocol in the IPv6 network to run IPFIX over IPv6.
  3.2 IPFIX and PSAMP
    PSAMP defines packet selection methods, their configuration at
    routers and probes and the reporting of packet information.
    PSAMP uses IPFIX as basis for exporting packet information
    [PSAMP-PROTO]. [PSAMP-INFO] describes further information
    elements for exporting packet information and reporting
    configuration information.
    The main difference between IPFIX and PSAMP is that IPFIX
    addresses the export of flow records whereas PSAMP addresses the
    export of packet records. Furthermore, PSAMP explicitly
    addresses remote configuration. It defines a MIB for the
    configuration of packet selection processes. Remote
    configuration is not (yet) addressed in IPFIX, but one could
    consider extending the PSAMP MIB to also allow configuration of
    IPFIX processes.
  3.3 IPFIX and RMON
    RMON [RFC3577] is a widely used monitoring system that gathers
    traffic data from RMON Agents in network devices. One major
    difference between RMON and IPFIX is that RMON uses SNMP for
    data export whereas IPFIX defines an own push-oriented protocol.
    RMON defines MIBs that contain the information to be exported.
    In IPFIX the data to be exported is defined as information
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    The most relevant MIBs for a comparison with IPFIX are the
    Application Performance Measurement MIB (APM-MIB) [RFC3729] and
    the Transport Performance Metrics MIB (TPM-MIB) [RFC4150].
    The APM-MIB has a complex system for tracking user application
    performance, with reporting about transactions and SLA threshold
    notification-trigger configuration, and persistence across DHCP
    lease expirations. It requires a full RMON2-MIB protocolDirTable
    The APM-MIB reports the performance of transactions. A
    transaction is a service oriented term and describes the data
    exchange from the transaction start (when a user requests a
    service) until its completion. The performance parameters
    include response times, throughput, streaming responsiveness and
    availability of services.
    The RMON transaction concept differs from the IPFIX flow
    concept. A flow is a very generic term that allows one to group
    IP packets in accordance with common properties.  In contrast to
    this, the term transaction is service-oriented and contains all
    data exchange required for service completion.
    In order to report such data with IPFIX one would probably need
    a specific combination of multiple flows and the ability to map
    those to the transaction. Due to the service-orientated focus of
    APM, also the required metrics differ. For instance, the RMON
    APM requires a metric for the responsiveness of services. Such
    metrics are not addressed in IPFIX.
    Furthermore, the APM-MIB allows the configuration of the
    transaction type to be monitored, i.e., it addresses the
    configuration of the metering process, which is currently not
    addressed in IPFIX.
    The APM MIB could be considered as an extension of the IPFIX
    metering process where the application performance of a
    combination of multiple flows is measured. If appropriate IEs
    would be defined in the IPFIX information model and the IPFIX
    device would support the APM MIB data collection, the solutions
    could be complementary. That means one could use IPFIX to export
    APM MIB transaction information.
    The TPM-MIB breaks out the APM-MIB transactions into sub-
    application level transactions. For instance a web request is
    broken down into DNS, TCP and HTTP sub-transactions.
    Such sub-transactions can be considered as bi-directional flows.
    With an appropriate flow definitions and the ability to map both
    directions of a flow (see section 4.6), one could measure and
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    report flow characteristics of such sub-application level
    transaction with IPFIX.
    The TPM-MIB requires APM-MIB and RMON2-MIB.
  3.4 IPFIX and IPPM
    The IPFIX protocol can be used to carry IPPM network performance
    metrics or information that can be used to calculate those
    metrics (see sections 2.5 and 2.7 for details and references).
  3.5 IPFIX and AAA
    AAA defines a protocol and architecture for authentication,
    authorization and accounting for service usage [RFC2903]. The
    DIAMETER protocol [RFC3588] is used for AAA communication, which
    is needed for network access services (Mobile IP, NASREQ, and
    ROAMOPS). The AAA architecture [RFC2903] provides a framework
    for extending AAA support to other services. DIAMETER defines
    the exchange of messages between AAA entities, e.g. between AAA
    clients at access devices and AAA servers, and among AAA
    servers. DIAMETER is used for the transfer of accounting
    records. In order to form accounting records for usage-based
    accounting measurement data from the network is required. IPFIX
    defines a protocol to export such data from routers, measurement
    probes and other devices. Therefore it looks promising to
    connect those two architectures.
    For all scenarios described here one has to keep in mind that
    IPFIX does not conform to the reliability requirements for
    usage-based billing described in [RFC2975] (see section 4.2).
    Using IPFIX without reliability extensions together with AAA
    would result in accounting scenarios that do not conform to
    usage-based billing requirements described in [RFC2975].
    As shown in section 2.1 accounting applications can directly
    incorporate an IPFIX collecting process to receive IPFIX records
    with information about the transmitted volume. Nevertheless, if
    an AAA infrastructure is in place, the cooperation between IPFIX
    (and especially IPFIX with reliability extensions) and AAA
    provides many valuable synergistic benefits. IPFIX records can
    provide the input for AAA accounting functions and provide the
    basis for the generation of DIAMETER accounting records.
    Further potential features include the mapping of a user ID to
    flow information (by using authentication information) or using
    the secure authorized exchange of DIAMETER accounting records
    with neighbor domains. The last feature is especially useful in
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    roaming scenarios where the user connects to a foreign network
    and the home provider generates the invoice.
    Coupling an IPFIX collecting process with AAA functions has also
    high potential for intrusion and attack detection. AAA controls
    network access and maintains data about users and nodes. AAA
    functions can help to identify the source of malicious traffic.
    Authorization functions are able to deny access to suspicious
    users or nodes. Therefore coupling those functions with an IPFIX
    collecting process can provide an efficient defense against
    network attacks. Sharing IPFIX records (either directly or
    encapsulated in DIAMETER) with neighbor providers allows an
    efficient inter-domain attack detection. The AAA infrastructure
    can also be used to configure measurement functions in the
    network as proposed in [RFC3334].
    Two possibilities exist to connect IPFIX and AAA:
    - Connecting via an AAA Client
    - Connecting via an Application Specific Module (ASM)
    Both are explained in the following sections. The approaches
    only require few additional functions. They do not require any
    changes to IPFIX or DIAMETER.
 3.5.1 Connecting via an AAA Client
    One possibility of connecting IPFIX and AAA is to run an AAA
    client on the IPFIX collector. This client can generate DIAMETER
    accounting messages and send them to an AAA server. The mapping
    of the flow information to a user ID can be done in the AAA
    server by using data from the authentication process. DIAMETER
    accounting messages can be sent to the accounting application or
    to other AAA servers (e.g. in roaming scenarios).
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                      IPFIX Applicability              August 2006
           +---------+  DIAMETER    +---------+
           |  AAA-S  |------------->|  AAA-S  |
           +---------+              +---------+
                | DIAMETER
         |  |  AAA-C |  |
         +  +--------+  |
         |              |
         |  Collector   |
                | IPFIX
          |  Exporter  |
    Figure 2: IPFIX collector connects to AAA server via AAA client
 3.5.2 Connecting via an Application Specific Module (ASM)
    Another possibility is to directly connect the IPFIX collector
    with the AAA server via an application specific module (ASM).
    Application specific modules have been proposed by the IRTF AAA
    architecture research group (AAARCH) in [RFC2903]. They act as
    an interface between AAA server and service equipment. In this
    case the IPFIX collector is part of the ASM. The ASM acts as an
    interface between the IPFIX protocol and the input interface of
    the AAA server. The ASM translates the received IPFIX data into
    an appropriate format for the AAA server. The AAA server then
    can add information about the user ID and generate a DIAMETER
    accounting record. This accounting record can be sent to an
    accounting application or to other AAA servers.
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                      IPFIX Applicability              August 2006
           +---------+  DIAMETER    +---------+
           |  AAA-S  |------------->|  AAA-S  |
           +---------+              +---------+
        |     ASM          |
        |  +------------+  |
        |  |  Collector |  |
                | IPFIX
          |  Exporter  |
    Figure 3: IPFIX connects to AAA server via ASM
  3.6 IPFIX and RTFM
    The Real-time Traffic Flow Measurement (RTFM) working group
    defined an architecture for flow measurement [RFC2722]. This
    section compares the Real-time Traffic Flow Measurement (RTFM)
    framework with the IPFIX framework.
 3.6.1   Architecture
    The RTFM architecture is very similar to the IPFIX architecture.
    It defines meter, meter reader and a manager as building blocks
    of the measurement architecture. The manager configures the
    meter and the meter reader collects data from the meter.
    In RTFM the building blocks communicate via SNMP.
    The IPFIX architecture [IPFIX-ARCH] defines metering, exporting
    and collecting processes. IPFIX speaks about processes instead
    of devices to clarify that multiple of those processes may be
    collocated on the same machine.
    Both definitions do not contradict each other. One could see the
    metering process as part of the meter and the collecting process
    as part of the meter reader.
    One difference is that IPFIX currently does not define a
    managing process, because remote configuration was at least
    initially out of scope for the working group.
 3.6.2    Flow Definition
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    RTFM and IPFIX both consider flows as a group of packets which
    share a common set of properties. A flow is completely specified
    by that set of values, together with a termination criterion
    (like inactivity timeout).
    A difference is that RTFM defines flows as bidirectional. An
    RTFM meter matches packets from B to A and A to B as separate
    parts of a single flow, and maintains two sets of packet and
    byte counters, one for each direction.
    IPFIX does not explicitly state whether flows are uni- or
    bidirectional. Nevertheless information elements for describing
    flow properties were defined only for one direction in [IPFIX-
    INFO]. Nevertheless, there are several solutions for reporting
    bi-directional flow information (see section 4.6).
 3.6.3   Configuration and Management
    In RTFM, remote configuration is the only way to configure a
    meter. This is done by using SNMP and a specific Meter MIB
    [RFC2720]. The IPFIX group currently does not address IPFIX
    remote configuration.
    IPFIX metering processes export the layout of data within their
    templates, from time to time. IPFIX collecting processes use
    that template information to determine how they should interpret
    the IPFIX flow data they receive.
 3.6.4   Data Collection
    One major difference between IPFIX and RTFM is the data
    collection model. RTFM retrieves data in pull mode whereas IPFIX
    uses a push mode model to send data to collecting processes.
    An RTFM meter reader pulls data from a meter by using SNMP. SNMP
    security on the meter determines whether a reader is allowed to
    pull data from it. An IPFIX exporting process is configured to
    export records to a specified list of IPFIX collecting
    processes. The condition when to send IPFIX records (e.g. flow
    termination) has to be configured in the exporting or metering
 3.6.5   Data Model Details
    RTFM defines all its attributes in the RTFM Meter MIB [RFC2720].
    IPFIX information elements are defined in [IPFIX-INFO].
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    RTFM uses continuously-incrementing 64-bit counters for the
    storage of the number of packets of a flow. The counters are
    never reset and just wrap back to zero if the maximum value is
    exceeded. Flows can be read at any time. The difference between
    counter readings gives the counts for activity in the interval
    between readings.
    IPFIX allows absolute (totalCounter) and relative counters
    (deltaCounter) [IPFIX-INFO]. The totalCounter is never reset and
    just wraps to zero if values are too large, exactly as the
    counters used in RTFM. The deltaCounter is reset to zero when
    the associated flow record is exported.
 3.6.6   Transport Protocol
    RTFM has a standards-track Meter MIB [RFC2720], which is used
    both to configure a meter and to store metering results.  The
    MIB provides a way to read lists of attributes with a single
    Object Identifier (called a 'package'), which reduces the SNMP
    overhead for flow data collection. SNMP, of course, normally
    uses UDP as its transport protocol. Since RTFM requires a
    reliable flow data transport system, an RTFM meter reader must
    time out and resend unanswered SNMP requests. Apart from being
    clumsy, this can limit the maximum data transfer rate from meter
    to meter reader.
    IPFIX is designed to work over a variety of different transport
    protocols.  SCTP [RFC2960] and SCTP-PR [RFC3758] are mandatory.
    UDP and TCP are optional.  In addition, the IPFIX protocol
    encodes data much more efficiently than SNMP does, hence IPFIX
    has lower data transport overheads than RTFM.
 3.6.7   Summary
    IPFIX exports flow information in push model by using SCTP, TCP
    or UDP. It currently does not address remote configuration. RTFM
    data collection is using the pull model and runs over SNMP. RTFM
    addresses remote configuration which also runs over SNMP. Both
    frameworks allow a very flexible flow definition, although RTFM
    is based on a bi-directional flow definition.
 4. Limitations
    The goal of this section is to show the limitations of IPFIX and
    to give advice where not to use IPFIX or in which cases
    additional considerations are required.
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                      IPFIX Applicability              August 2006
  4.1 Using IPFIX for other Applications than Listed in RFC3917
    IPFIX provides a generic export mechanism. Due to its template
    based structure, it is a quite flexible protocol. Network
    operators and users may want to use it also for other
    applications than those described in [RFC3917].
    Apart from sending raw flow information it can be used to send
    per-packet data, aggregated or post-processed data. For this new
    templates and information elements can be defined if needed. Due
    to its push mode operation IPFIX is also suited to send network
    initiated events like alarms and other notifications. It can be
    used for exchanging information among network nodes to
    autonomously improve network operation.
    Nevertheless, the IPFIX design is based on the requirements that
    originate only from the target applications stated in [RFC3917].
    Using IPFIX for other purposes requires a careful checking of
    IPFIX capabilities against application requirements. Only with
    this one can decide whether IPFIX is a suitable protocol to meet
    the needs of a specific application.
  4.2 Using IPFIX for Billing (Reliability Limitations)
    The reliability requirements defined in [RFC3917] are not
    sufficient to guarantee the level of reliability that is needed
    for usage-based billing systems as described in [RFC2975]. In
    particular IPFIX does not support the following features
    required by [RFC2975]:
    - Record loss: IPFIX allows the usage of different transport
       protocols for the transfer of data records. Resilience against
       the loss of IPFIX data records can be only provided if TCP or
       SCTP is used for the transfer of data records.
    - Network or device failures: IPFIX does allow the usage of
       multiple collectors for one exporter, but it neither specifies
       nor demands the use of multiple collectors for the
       provisioning of fault tolerance.
    - Detection and elimination of duplicate records: This is
       currently not supported by IPFIX.
    - Application layer acknowledgements: IPFIX does not support the
       control of measurement and exporting processes by higher level
       applications. Application layer acknowledgements are necessary
       e.g. to inform the exporter in case the application is not
       able to process the data exported with IPFIX. Such
       acknowledgements are not supported in IPFIX.
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                      IPFIX Applicability              August 2006
    Further features like archival accounting and pre-authorization,
    are out of scope of the IPFIX specification but need to be
    realized in billing system architectures as described in
  4.3 Using a Different Transport Protocol than SCTP
    SCTP is the preferred protocol for IPFIX, i.e. a conforming
    implementation must work over SCTP. Although IPFIX can also work
    over TCP or UDP, both protocols have drawbacks [IPFIX-PROTO].
    Users should make sure they have good reasons before using
    protocols other than SCTP in a specific environment.
  4.4 Push vs. Pull Mode
    IPFIX works in push mode. That means IPFIX records are
    automatically exported without the need to wait for a request.
    The responsibility for initiating a data export lies with the
    exporting process.
    Criteria for exporting data need to be configured at the
    exporting process. Therefore push mode has more benefits if the
    trigger for data export is related to events at the exporting
    process (e.g. flow termination, memory shortage due to large
    amount of flows, etc.). If the protocol used pull mode, the
    exporting process would need to wait for a request to send the
    data. With push mode it can send data immediately e.g. before
    memory shortage would require a discarding of data.
    With push mode one can prevent the overloading of resources at
    the exporting process by simply exporting the information as
    soon as certain thresholds are about to be exceeded. Therefore
    exporting criteria are often related to traffic characteristics
    (e.g. flow timeout) or resource limitations (e.g. size of flow
    cache). But traffic characteristics are usually quite dynamic
    and often impossible to predict. If those are used to trigger
    flow export, the exporting rate and the resource consumption for
    flow export becomes variable and unpredictable.
    Pull mode has advantages if the trigger for data export is
    related to events at the collecting process (e.g. a specific
    application requests immediate input).
    In a pull mode, a request could simply be forwarded to the
    exporting process. In a push mode, the exporting configuration
    must be changed to trigger the export of the requested data.
    Furthermore, with pull mode one can prevent the overloading of
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                      IPFIX Applicability              August 2006
    the collecting process by the arrival of more records than it
    can process.
    Whether this is a relevant drawback depends on the flexibility
    of the IPFIX configuration and how IPFIX configuration rules are
  4.5 Template ID number
    The IPFIX specification limits the different template ID numbers
    that can be assigned to the newly generated template records in
    an observation domain. In particular, template IDs up to 255 are
    reserved for Template or option sets (or other sets to be
    created) and template IDs from 256 to 65535 are assigned to data
    sets. In the case of many exports requiring many different
    templates, the set of Template IDs could be exhausted.
  4.6 Exporting Bidirectional Flow Information
    Although IPFIX does not explicitly state that flows are
    unidirectional, information elements that describe flow
    characteristics are defined only for one direction in [IPFIX-
    INFO]. [IPFIX-PROTO] allows the reporting of multiple identical
    information elements in one flow record. With this information
    elements for forward and reverse direction can be reported in
    one flow record.
    But this is not sufficient. Using this feature for reporting
    bidirectional flow information would require an agreement on the
    semantic of information elements (e.g. first counter is counter
    for the forward direction, second counter for reverse
    Another option is to use two adjacent flow records to report
    both directions of a bidirectional flow separately. This
    approach requires additional means for mapping those records and
    is quite inefficient due to the redundant reporting of flow
  4.7 Remote Configuration
    Remote configuration was initially out of scope of the IPFIX
    working group in order to concentrate on the protocol
    specification. Therefore there is currently no standardized way
    to configure IPFIX processes remotely. Nevertheless due to the
    broad need for this feature, it is quite likely that solutions
    for this will be standardized soon.
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                      IPFIX Applicability              August 2006
 5. Security Considerations
    This document describes the usage of IPFIX in various scenarios.
    Security requirements for IPFIX target applications and security
    considerations for IPFIX are addressed in [RFC3917] and [IPFIX-
    PROTO]. Those requirements have to be met for the usage of IPFIX
    for all scenarios described in this document. To our current
    knowledge, the usage scenarios proposed in section 2 do not
    induce further security hazards.
    The threat level to IPIFX itself may depend on the usage
    scenario of IPFIX. The usage of IPFIX for accounting or attack
    detection may increase the incentive to attack IPFIX itself.
    Nevertheless, security considerations have to be taken into
    account in all described scenarios.
    As described in the security considerations in [IPFIX-PROTO]
    security incidents can become a threat to IPFIX processes
    themselves, even if IPIFX is not the target of the attack. If an
    attack generates a large amount of flows (e.g. by sending
    packets with spoofed addresses or simulating flow termination)
    exporting and collecting process may get overloaded by the
    immense amount of records that are exported. A flexible
    deployment of packet or flow sampling methods can be useful to
    prevent the exhaustion of resources.
    Section 3 of this document describes how IPFIX can be used in
    combination with other technologies. New security hazards can
    arise when two individually secure technologies or architectures
    are combined. For the combination of AAA with IPFIX an
    application specific module (ASM) or an IPFIX collector can
    function as transit point for the messages. One has to ensure
    that at this point the applied security mechanisms (e.g.
    encryption of messages) are maintained.
 6. IANA Considerations
    This document has no actions for IANA.
 7. Normative References
    [IPFIX-INFO] J. Quittek, S. Bryant, J. Meyer, "Information Model
                  for IP Flow Information Export", Internet Draft
                  <draft-ietf-ipfix-info-14>, work in progress,
                  October 2006
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                      IPFIX Applicability              August 2006
    [IPFIX-PROTO] B. Claise (Editor), "IPFIX Protocol Specification",
                  Internet Draft <draft-ietf-ipfix-protocol-24.txt>,
                  work in progress, November 2006
    [PSAMP-INFO] T. Dietz, F. Dressler, G. Carle, B. Claise,
                  "Information Model for Packet Sampling Exports",
                  Internet Draft <draft-ietf-psamp-info-05.txt>, work
                  in progress, October 2006
    [RFC3917]    J. Quittek, T. Zseby, B. Claise, S. Zander,
                  "Requirements for IP Flow Information Export", RFC
                  3917, October 2004
 8. Informative References
    [Brow00]     Nevil Brownlee, "Packet Matching for NeTraMet
    [DuGr00]     Nick Duffield, Matthias Grossglauser, "Trajectory
                  Sampling for Direct Traffic Observation",
                  Proceedings of ACM SIGCOMM 2000, Stockholm, Sweden,
                  August 28 - September 1, 2000
    [GrDM98]     Ian D. Graham, Stephen F. Donnelly, Stele Martin,
                  Jed Martens, John G. Cleary, "Nonintrusive and
                  Accurate Measurement of Unidirectional Delay and
                  Delay Variation on the Internet", INET'98, Geneva,
                  Switzerland, 21-24 July, 1998
    [IPFIX-ARCH] G. Sadasivan, N. Brownlee, B. Claise, J. Quittek,
                  "Architecture for IP Flow Information Export",
                  Internet Draft <draft-ietf-ipfix-architecture-
                  08.txt>, work in progress, March 2005
    [PSAMP-PROTO] Benoit Claise (Ed.), Packet Sampling (PSAMP)
                  Protocol Specifications, Internet Draft <draft-
                  ietf-psamp-protocol-07.txt>, work in progress,
                  October 2006
    [PSAMP-TECH]  T. Zseby, M. Molina, N. Duffield, S. Niccolini, F.
                  Raspall, "Sampling and Filtering Techniques for IP
                  Packet Selection" Internet Draft <draft-ietf-psamp-
                  sample-tech-07.txt>, work in progress, July 2005
    [RFC3246]    B. Davie, et al., "An Expedited Forwarding PHB",
                  RFC 3246, March 2002
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                      IPFIX Applicability              August 2006
    [RFC2679]    G. Almes, S. Kalidindi, M. Zekauskas, "A One-way
                  Delay Metric for IPPM", RFC 2679, September 1999
    [RFC2680]    G. Almes, S. Kalidindi, M. Zekauskas, "A One-way
                  Packet Loss Metric for IPPM",RFC 2680, September
    [RFC2681]    G. Almes, S. Kalidindi, M. Zekauskas, "A Round-trip
                  Delay Metric for IPPM", RFC 2681, September 1999
    [RFC2702]    D. Awduche, J. Malcolm, J. Agogbua, M. O'Dell, J.
                  McManus, "Requirements for Traffic Engineering Over
                  MPLS", RFC 2702, September 1999
    [RFC2720]    N. Brownlee, Traffic Flow Measurement: Meter MIB,
                  RFC2720 October 1999
    [RFC2722]    Brownlee, N., Mills, C., G. Ruth, "Traffic Flow
                  Measurement: Architecture", RFC 2722, October 1999
    [RFC2903]    C. de Laat, G. Gross, L. Gommans, J. Vollbrecht, D.
                  Spence, "Generic AAA Architecture", RFC 2903,
                  August 2000
    [RFC2960]    R. Stewart (ed.) "Stream Control Transmission
                  Protocol", RFC 2960, October 2000
    [RFC2975]    B. Aboba, J. Arkko, D. Harrington, "Introduction to
                  Accounting Management", RFC 2975, October 2000
    [RFC3330]    IANA, "Special-Use IPv4 Addresses", RFC 3330
                  September 2002
    [RFC3334]    T. Zseby, S. Zander, G. Carle, "Policy-Based
                  Accounting", RFC 3334, October 2002
    [RFC3393]    C. Demichelis, P. Cimento, "IP Packet Delay
                  Variation Metric for IPPM", RFC 3393, November 2002
    [RFC3577]    S. Waldbusser, R. Cole, C. Kalbfleisch,
                  D.Romascanu, "Introduction to the Remote Monitoring
                  (RMON) Family of MIB Module", RFC 3577, August 2003
    [RFC3588]    P. Calhoun, J. Loughney, E. Guttman, G. Zorn, J.
                  Arkko, "Diameter Base Protocol", RFC 3588,
                  September 2003
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                      IPFIX Applicability              August 2006
    [RFC3729]    S. Waldbusser, "Application Performance Measurement
                  MIB", RFC 3729, March 2004
    [RFC3758]    R. Stewart, M. Ramalho, Q. Xie, M. Tuexen, P.
                  Conrad, "Stream Control Transmission Protocol
                  (SCTP) Partial Reliability Extension", RFC 3758,
                  May 2004
    [RFC4150]    R. Dietz, R. Cole, "Transport Performance Metrics
                  MIB", RFC 4150, August 2005
    [ZsZC01]     T. Zseby, S. Zander, G. Carle, "Evaluation of
                  Building Blocks for Passive One-way-delay
                  Measurements", Proceedings of Passive and Active
                  Measurement Workshop (PAM 2001), Amsterdam, The
                  Netherlands, April 23-24, 2001
 9. Acknowledgements
    We would like to thank the following persons for their
    contribution, discussion on the mailing list and valuable
    Sebastian Zander
    Robert Loewe
    Reinaldo Penno
    Lutz Mark
    Andy Biermann
    Part of the work has been developed in the research project 6QM
    co-funded with support from the European Commission.
 10.Authors' Addresses
    Tanja Zseby
    Fraunhofer Institute for Open Communication Systems (FOKUS)
    Kaiserin-Augusta-Allee 31
    10589 Berlin, Germany
    Phone: +49 30 3463 7153
    Elisa Boschi
    Hitachi Europe SAS
    Immeuble Le Theleme
    1503 Route des Dolines
    06560 Valbonne, France
    Phone: +33 4 89874180
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                      IPFIX Applicability              August 2006
    Nevil Brownlee
    9500 Gilman Drive
    La Jolla, CA 92093-0505
    Phone : +1 858 534 8338
    Email :
    Benoit Claise
    Cisco Systems
    De Kleetlaan 6a b1
    1831 Diegem
    Phone: +32 2 704 5622
 11.Full Copyright Statement
    Copyright (C) The IETF Trust (2007).
    This document is subject to the rights, licenses and
    restrictions contained in BCP 78, and except as set forth
    therein, the authors retain all their rights.
 12. Disclaimer
    This document and the information contained herein are provided
 13. Intellectual Property Statement
    The IETF has been notified by Cisco Systems of intellectual
    property rights claimed in regard to some or all of the
    specification contained in this document. The IPR disclosure was
    submitted to the IETF Secretariat on 2007-01-03. More
    information can be found on the "IETF Page of Intellectual
    Property Rights Disclosures"
    ( The title of
    the IPR disclosure is "Cisco's Statement about IPR claimed in
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                      IPFIX Applicability              August 2006
    The IETF takes no position regarding the validity or scope of
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    claimed to pertain to the implementation or use of the
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    Copies of IPR disclosures made to the IETF Secretariat and any
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    The IETF invites any interested party to bring to its attention
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