<pre>Internet Engineering Task Force (IETF)                         B. Claise
Request for Comments: 6759                                     P. Aitken
Category: Informational                                     N. Ben-Dvora
ISSN: 2070-1721                                      Cisco Systems, Inc.
                                                           November 2012


           <span class="h1">Cisco Systems Export of Application Information in</span>
                   <span class="h1">IP Flow Information Export (IPFIX)</span>

Abstract

   This document specifies a Cisco Systems extension to the IPFIX
   information model specified in <a href="./rfc5102">RFC 5102</a> to export application
   information.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see <a href="./rfc5741#section-2">Section&nbsp;2 of RFC 5741</a>.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   <a href="http://www.rfc-editor.org/info/rfc6759">http://www.rfc-editor.org/info/rfc6759</a>.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to <a href="https://www.rfc-editor.org/bcp/bcp78">BCP 78</a> and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.





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Table of Contents

   <a href="#section-1">1</a>. Introduction ....................................................<a href="#page-3">3</a>
      <a href="#section-1.1">1.1</a>. Application Information Use Cases ..........................<a href="#page-5">5</a>
      <a href="#section-1.2">1.2</a>. Conventions Used in This Document ..........................<a href="#page-5">5</a>
   <a href="#section-2">2</a>. IPFIX Documents Overview ........................................<a href="#page-5">5</a>
   <a href="#section-3">3</a>. Terminology .....................................................<a href="#page-6">6</a>
      <a href="#section-3.1">3.1</a>. New Terminology ............................................<a href="#page-6">6</a>
   <a href="#section-4">4</a>. applicationId Information Element Specification .................<a href="#page-6">6</a>
      <a href="#section-4.1">4.1</a>. Existing Classification Engine IDs .........................<a href="#page-7">7</a>
      <a href="#section-4.2">4.2</a>. Selector ID Length per Classification ID ..................<a href="#page-11">11</a>
      <a href="#section-4.3">4.3</a>. Application Name Options Template Record ..................<a href="#page-12">12</a>
      <a href="#section-4.4">4.4</a>. Resolving IANA L4 Port Discrepancies ......................<a href="#page-13">13</a>
   <a href="#section-5">5</a>. Grouping Applications with Attributes ..........................<a href="#page-13">13</a>
      <a href="#section-5.1">5.1</a>. Options Template Record for Attribute Values ..............<a href="#page-15">15</a>
   <a href="#section-6">6</a>. Application ID Examples ........................................<a href="#page-15">15</a>
      <a href="#section-6.1">6.1</a>. Example 1: Layer 2 Protocol ...............................<a href="#page-15">15</a>
      <a href="#section-6.2">6.2</a>. Example 2: Standardized IANA Layer 3 Protocol .............<a href="#page-16">16</a>
      <a href="#section-6.3">6.3</a>. Example 3: Proprietary Layer 3 Protocol ...................<a href="#page-17">17</a>
      <a href="#section-6.4">6.4</a>. Example 4: Standardized IANA Layer 4 Port .................<a href="#page-18">18</a>
      <a href="#section-6.5">6.5</a>. Example 5: Layer 7 Application ............................<a href="#page-19">19</a>
      6.6. Example 6: Layer 7 Application with Private
           Enterprise Number (PEN) ...................................<a href="#page-21">21</a>
      <a href="#section-6.7">6.7</a>. Example: Port Obfuscation .................................<a href="#page-22">22</a>
      <a href="#section-6.8">6.8</a>. Example: Application Name Mapping Options Template ........<a href="#page-23">23</a>
      <a href="#section-6.9">6.9</a>. Example: Attributes Values Options Template Record ........<a href="#page-24">24</a>
   <a href="#section-7">7</a>. IANA Considerations ............................................<a href="#page-25">25</a>
      <a href="#section-7.1">7.1</a>. New Information Elements ..................................<a href="#page-25">25</a>
           <a href="#section-7.1.1">7.1.1</a>. applicationDescription .............................<a href="#page-25">25</a>
           <a href="#section-7.1.2">7.1.2</a>. applicationId ......................................<a href="#page-26">26</a>
           <a href="#section-7.1.3">7.1.3</a>. applicationName ....................................<a href="#page-26">26</a>
           <a href="#section-7.1.4">7.1.4</a>. classificationEngineId .............................<a href="#page-26">26</a>
           <a href="#section-7.1.5">7.1.5</a>. applicationCategoryName ............................<a href="#page-29">29</a>
           <a href="#section-7.1.6">7.1.6</a>. applicationSubCategoryName .........................<a href="#page-29">29</a>
           <a href="#section-7.1.7">7.1.7</a>. applicationGroupName ...............................<a href="#page-29">29</a>
           <a href="#section-7.1.8">7.1.8</a>. p2pTechnology ......................................<a href="#page-29">29</a>
           <a href="#section-7.1.9">7.1.9</a>. tunnelTechnology ...................................<a href="#page-30">30</a>
           <a href="#section-7.1.10">7.1.10</a>. encryptedTechnology ...............................<a href="#page-30">30</a>
      <a href="#section-7.2">7.2</a>. Classification Engine ID Registry .........................<a href="#page-30">30</a>
   <a href="#section-8">8</a>. Security Considerations ........................................<a href="#page-30">30</a>
   <a href="#section-9">9</a>. References .....................................................<a href="#page-31">31</a>
      <a href="#section-9.1">9.1</a>. Normative References ......................................<a href="#page-31">31</a>
      <a href="#section-9.2">9.2</a>. Informative References ....................................<a href="#page-32">32</a>
   <a href="#section-10">10</a>. Acknowledgements ..............................................<a href="#page-33">33</a>
   <a href="#appendix-A">Appendix A</a>. Additions to XML Specification of IPFIX Information
               (Non-normative) .......................................<a href="#page-34">34</a>
   <a href="#appendix-B">Appendix B</a>. Port Collisions Tables (Non-normative) ................<a href="#page-39">39</a>
   <a href="#appendix-C">Appendix C</a>. Application Registry Example (Non-normative) ..........<a href="#page-43">43</a>



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List of Figures

   Figure 1: applicationId Information Element .......................<a href="#page-7">7</a>
   Figure 2: Selector ID Encoding ...................................<a href="#page-12">12</a>

List of Tables

   Table 1: Existing Classification Engine IDs .......................<a href="#page-7">7</a>
   Table 2: Selector ID Default Length per Classification
            Engine ID ...............................................<a href="#page-11">11</a>
   Table 3: Application ID Static Attributes ........................<a href="#page-13">13</a>
   Table 4: Different Protocols on UDP and TCP ......................<a href="#page-39">39</a>
   Table 5: Different Protocols on SCTP and TCP .....................<a href="#page-40">40</a>

<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>.  Introduction</span>

   Today, service providers and network administrators are looking for
   visibility into the packet content rather than just the packet
   header.  Some network devices' Metering Processes inspect the packet
   content and identify the applications that are utilizing the network
   traffic.  Applications in this context are defined as networking
   protocols used by networking processes that exchange packets between
   them (such as web applications, peer-to-peer applications, file
   transfer, e-mail applications, etc.).  Applications can be further
   characterized by other criteria, some of which are application
   specific.  Examples include: web application to a specific domain,
   per-user specific traffic, a video application with a specific codec,
   etc.

   The application identification is based on several different methods
   or even a combination of methods:

   1. L2 (Layer 2) protocols (such as ARP (Address Resolution Protocol),
      PPP (Point-to-Point Protocol), LLDP (Link Layer Discovery
      Protocol))

   2. IP protocols (such as ICMP (Internet Control Message Protocol),
      IGMP (Internet Group Management Protocol), GRE (Generic Routing
      Encapsulation)

   3. TCP or UDP ports (such as HTTP, Telnet, FTP)

   4. Application layer header (of the application to be identified)

   5. Packet data content

   6. Packets and traffic behavior




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   The exact application identification methods are part of the Metering
   Process internals that aim to provide an accurate identification and
   minimize false identification.  This task requires a sophisticated
   Metering Process since the protocols do not behave in a standard
   manner.

   1. Applications use port obfuscation where the application runs on a
      different port than the IANA assigned one.  For example, an HTTP
      server might run on TCP port 23 (assigned to telnet in
      [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>]).

   2. IANA port registries do not accurately reflect how certain ports
      are "commonly" used today.  Some ports are reserved, but the
      application either never became prevalent or is not in use today.

   3. The application behavior and identification logic become more and
      more complex.

   For that reason, such Metering Processes usually detect applications
   based on multiple mechanisms in parallel.  Detection based only on
   port matching might wrongly identify the application.  If the
   Metering Process is capable of detecting applications more
   accurately, it is considered to be stronger and more accurate.

   Similarly, a reporting mechanism that uses L4 port based applications
   only, such as L4:&lt;known port&gt;, would have similar issues.  The
   reporting system should be capable of reporting the applications
   classified using all types of mechanisms.  In particular,
   applications that do not have any IANA port definition.  While a
   mechanism to export application information should be defined, the L4
   port being used must be exported using the destination port
   (destinationTransportPort at [<a href="#ref-IANA-IPFIX" title="&quot;IP Flow Information Export (IPFIX) Entities&quot;">IANA-IPFIX</a>]) in the corresponding IPFIX
   record.

   Applications could be identified at different OSI layers, from layer
   2 to layer 7.  For example, the Link Layer Distribution Protocol
   (LLDP) [<a href="#ref-LLDP" title="&quot;Standard for Local and metropolitan area networks - Station and Media Access Control Connectivity Discovery&quot;">LLDP</a>] can be identified in layer 2, ICMP can be identified in
   layer 3 [<a href="#ref-IANA-PROTO" title="&quot;Protocol Numbers&quot;">IANA-PROTO</a>], HTTP can be identified in layer 4 [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>],
   and Webex can be identified in layer 7.

   While an ideal solution would be an IANA registry for applications
   above (or inside the payload of) the well-known ports [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>],
   this solution is not always possible.  Indeed, the specifications for
   some applications embedded in the payload are not available.  Some
   reverse engineering as well as a ubiquitous language for application
   identification would be required conditions to be able to manage an
   IANA registry for these types of applications.  Clearly, these are
   blocking factors.



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   This document specifies the Cisco Systems application information
   encoding (as described in <a href="#section-4">Section 4</a>) to export the application
   information with the IPFIX protocol [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>].  However, the layer 7
   application registry values are out of scope of this document.

<span class="h3"><a class="selflink" id="section-1.1" href="#section-1.1">1.1</a>.  Application Information Use Cases</span>

   There are several use cases for application information:

   1. Application Visibility

      This is one of the main cases for using application information.
      Network administrators are using application visibility to
      understand the main network consumers, network trends, and user
      behavior.

   2. Security Functions

      Application knowledge is sometimes used in security functions in
      order to provide comprehensive functions such as Application-based
      firewall, URL filtering, parental control, intrusion detection,
      etc.

   All of the above use cases require exporting application information
   to provide the network function itself or to log the network function
   operation.

<span class="h3"><a class="selflink" id="section-1.2" href="#section-1.2">1.2</a>.  Conventions Used in This Document</span>

   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 <a href="./rfc2119">RFC 2119</a> [<a href="./rfc2119" title="&quot;Key words for use in RFCs to Indicate Requirement Levels&quot;">RFC2119</a>].

<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>.  IPFIX Documents Overview</span>

   The IPFIX protocol [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>] provides network administrators with
   access to IP Flow information.

   The architecture for the export of measured IP Flow information out
   of an IPFIX Exporting Process to a Collecting Process is defined in
   the IPFIX Architecture [<a href="./rfc5470" title="&quot;Architecture for IP Flow Information Export&quot;">RFC5470</a>], per the requirements defined in <a href="./rfc3917">RFC</a>
   <a href="./rfc3917">3917</a> [<a href="./rfc3917" title="&quot;Requirements for IP Flow Information Export (IPFIX)&quot;">RFC3917</a>].

   The IPFIX Architecture [<a href="./rfc5470" title="&quot;Architecture for IP Flow Information Export&quot;">RFC5470</a>] specifies how IPFIX Data Records and
   Templates are carried via a congestion-aware transport protocol from
   IPFIX Exporting Processes to IPFIX Collecting Processes.





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   IPFIX has a formal description of IPFIX Information Elements, their
   names, types, and additional semantic information, as specified in
   the IPFIX information model [<a href="./rfc5102" title="&quot;Information Model for IP Flow Information Export&quot;">RFC5102</a>].

   In order to gain a level of confidence in the IPFIX implementation,
   probe the conformity and robustness, and allow interoperability, the
   Guidelines for IPFIX Testing [<a href="./rfc5471" title="&quot;Guidelines for IP Flow Information Export (IPFIX) Testing&quot;">RFC5471</a>] presents a list of tests for
   implementers of compliant Exporting Processes and Collecting
   Processes.

   The Bidirectional Flow Export [<a href="./rfc5103" title="&quot;Bidirectional Flow Export Using IP Flow Information Export (IPFIX)&quot;">RFC5103</a>] specifies a method for
   exporting bidirectional flow (biflow) information using the IPFIX
   protocol, representing each biflow using a single Flow Record.

   "Reducing Redundancy in IP Flow Information Export (IPFIX) and Packet
   Sampling (PSAMP) Reports" [<a href="./rfc5473" title="&quot;Reducing Redundancy in IP Flow Information Export (IPFIX) and Packet Sampling (PSAMP) Reports&quot;">RFC5473</a>] specifies a bandwidth-saving
   method for exporting Flow or packet information, by separating
   information common to several Flow Records from information specific
   to an individual Flow Record: common Flow information is exported
   only once.

<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>.  Terminology</span>

   IPFIX-specific terminology used in this document is defined in
   <a href="#section-2">Section 2</a> of the IPFIX protocol specification [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>].  As in
   [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>], these IPFIX-specific terms have the first letter of a word
   capitalized when used in this document.

<span class="h3"><a class="selflink" id="section-3.1" href="#section-3.1">3.1</a>.  New Terminology</span>

   Application ID

      A unique identifier for an application.

   When an application is detected, the most granular application is
   encoded in the Application ID.

<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>.  applicationId Information Element Specification</span>

   This document specifies the applicationId Information Element, which
   is a single field composed of two parts:

   1. 8 bits of Classification Engine ID.  The Classification Engine can
      be considered as a specific registry for application assignments.

   2. n bits of Selector ID.  The Selector ID length varies depending on
      the Classification Engine ID.




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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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Class. Eng. ID|         Selector ID  ...                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             ...                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 1: applicationId Information Element

   Classification Engine ID

      A unique identifier for the engine that determined the Selector
      ID.  Thus, the Classification Engine ID defines the context for
      the Selector ID.

   Selector ID

      A unique identifier of the application for a specific
      Classification Engine ID.  Note that the Selector ID length varies
      depending on the Classification Engine ID.

   The Selector ID term is a similar concept to the selectorId
   Information Element, specified in the PSAMP Protocol
   [<a href="./rfc5476" title="&quot;Packet Sampling (PSAMP) Protocol Specifications&quot;">RFC5476</a>][RFC5477].

<span class="h3"><a class="selflink" id="section-4.1" href="#section-4.1">4.1</a>.  Existing Classification Engine IDs</span>

   The following Classification Engine IDs have been allocated:

   Name         Value  Description

                0      Invalid.

   IANA-L3      1      The Assigned Internet Protocol
                       Number (layer 3 (L3)) is exported
                       in the Selector ID.
                       See [<a href="#ref-IANA-PROTO" title="&quot;Protocol Numbers&quot;">IANA-PROTO</a>].

   PANA-L3      2      Proprietary layer 3 definition.
                       An enterprise can export its own
                       layer 3 protocol numbers.  The
                       Selector ID has a global
                       significance for all devices from
                       the same enterprise.






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   IANA-L4      3      The IANA layer 4 (L4) well-known
                       port number is exported in the
                       Selector ID.  See [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>].
                       Note: as an IPFIX flow is
                       unidirectional, it contains the
                       destination port.

   PANA-L4      4      Proprietary layer 4 definition.
                       An enterprise can export its own
                       layer 4 port numbers.  The
                       Selector ID has global
                       significance for devices from the
                       same enterprise.  Example: IPFIX was
                       pre-assigned the port 4739 using the IANA
                       early allocation process [<a href="./rfc4020" title="&quot;Early IANA Allocation of Standards Track Code Points&quot;">RFC4020</a>] years
                       before the document was published as an RFC.
                       While waiting for the RFC and its associated
                       IANA registration, Selector ID 4739
                       was used with this PANA-L4.

                5      Reserved.

   USER-        6      The Selector ID represents
   Defined             applications defined by the user
                       (using CLI, GUI, etc.) based on
                       the methods described in <a href="#section-1">Section</a>
                       <a href="#section-1">1</a>.  The Selector ID has a local
                       significance per device.

                7      Reserved.

                8      Reserved.

                9      Reserved.

                10     Reserved.

                11     Reserved.

   PANA-L2      12     Proprietary layer 2 (L2)
                       definition.  An enterprise can
                       export its own layer 2
                       identifiers.  The Selector ID
                       represents the enterprise's
                       unique global layer 2
                       applications.  The Selector ID has
                       a global significance for all




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                       devices from the same enterprise.
                       Examples include Cisco Subnetwork
                       Access Protocol (SNAP).

   PANA-L7      13     Proprietary layer 7 definition.
                       The Selector ID represents the
                       enterprise's unique global ID for
                       layer 7 applications.  The
                       Selector ID has a global
                       significance for all devices from
                       the same enterprise.  This
                       Classification Engine ID is used
                       when the application registry is
                       owned by the Exporter
                       manufacturer (referred to as the
                       "enterprise" in this document).

                14     Reserved.

                15     Reserved.

                16     Reserved.

                17     Reserved.

   ETHERTYPE    18     The Selector ID represents the
                       well-known Ethertype.  See
                       [<a href="#ref-ETHERTYPE">ETHERTYPE</a>].

   LLC          19     The Selector ID represents the
                       well-known IEEE 802.2 Link Layer
                       Control (LLC) Destination Service
                       Access Point (DSAP).  See [<a href="#ref-LLC" title="&quot;LOGICAL LINK CONTROL (LLC) PUBLIC LISTING&quot;">LLC</a>].


   PANA-L7-     20     Proprietary layer 7 definition,
   PEN                 including a Private Enterprise
                       Number (PEN) [<a href="#ref-IANA-PEN" title="&quot;PRIVATE ENTERPRISE NUMBERS&quot;">IANA-PEN</a>] to identify
                       that the application registry
                       being used is not owned by the
                       Exporter manufacturer or to
                       identify the original
                       enterprise in the case of a
                       mediator or 3rd party device.  The
                       Selector ID represents the
                       enterprise unique global ID for
                       the layer 7 applications.  The




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                       Selector ID has a global
                       significance for all devices from
                       the same enterprise.

                21 to
                 255   Available (255 is the maximum
                       Engine ID)

       Table 1: Existing Classification Engine IDs

   "PANA = Proprietary Assigned Number Authority".  In other words, an
   enterprise specific version of IANA for internal IDs.

   The PANA-L7 Classification Engine ID SHOULD be used when the
   application registry is owned by the Exporter manufacturer.  Even if
   the application registry is owned by the Exporter manufacturer, the
   PANA-L7-PEN MAY be used, specifying the manufacturer.

   For example, if Exporter A (from enterprise-A) wants to export its
   enterprise-A L7 registry, then it uses the PANA-L7 Classification
   Engine ID.  If Exporter B (from enterprise-B) wants to export its
   enterprise-B L7 registry, then it also uses the PANA-L7
   Classification Engine ID.

   The mechanism for the Collector to know about the Exporter PEN is out
   of scope of this document.  Possible tracks are SNMP polling, an
   Options Template exporting the privateEnterpriseNumber Information
   Element [<a href="#ref-IANA-IPFIX" title="&quot;IP Flow Information Export (IPFIX) Entities&quot;">IANA-IPFIX</a>], hardcoded value, etc.

   An Exporter may classify the application according to another
   vendor's application registry.  For example, an IPFIX Mediator
   [<a href="./rfc6183" title="&quot;IP Flow Information Export (IPFIX) Mediation: Framework&quot;">RFC6183</a>] may need to re-export applications received from different
   Exporters using different PANA-L7 application registries.  For
   example, if Exporter C (from enterprise-C) wants to reuse enterprise-
   D's application registry, then it uses PANA-L7-PEN with enterprise-
   D's PEN.

   When reporting application information from multiple Exporters from
   different enterprises (different PENs), the PANA-L7-PEN
   Classification Engine MUST be used in exported Flow Records, which
   allows the original enterprise ID to be reported.  The ID of the
   enterprise that defined the Application ID is identified by the
   enterprise's PEN.  For example, an IPFIX Mediator aggregates traffic
   from some Exporters which report enterprise-E applications and other
   Exporters that report enterprise-F applications.

   An example is displayed in <a href="#section-6.6">Section 6.6</a>.




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   Note that the PANA-L7 Classification Engine ID is also used for
   resolving IANA L4 port Discrepancies (see <a href="#section-4.4">Section 4.4</a>).

   The list in Table 1 is maintained by IANA thanks to the registry
   within the classificationEngineId Information Element.  See the IANA
   Considerations section.  The Classification Engine ID is part of the
   Application ID encoding, so the classificationEngineId Information
   Element is currently not required by the specifications in this
   document.  However, this Information Element was created for
   completeness, as it was anticipated that this Information Element
   will be required in the future.

<span class="h3"><a class="selflink" id="section-4.2" href="#section-4.2">4.2</a>.  Selector ID Length per Classification ID</span>

   As the Selector ID part of the Application ID is variable based on
   the Classification Engine ID value, the applicationId SHOULD be
   encoded in a variable-length Information Element [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>] for IPFIX
   export.

   The following table displays the Selector ID default length for the
   different Classification Engine IDs.

      Classification               Selector ID default
      Engine ID Name               length (in bytes)

      IANA-L3                      1

      PANA-L3                      1

      IANA-L4                      2

      PANA-L4                      2

      USER-Defined                 3

      PANA-L2                      5

      PANA-L7                      3

      ETHERTYPE                    2

      LLC                          1

      PANA-L7-PEN                  3 (*)

               Table 2: Selector ID Default Length
                  per Classification Engine ID




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   (*) There are an extra 4 bytes for the PEN.  However, the PEN is not
   considered part of the Selector ID.

   If a legacy protocol such as NetFlow version 9 [<a href="./rfc3954" title="&quot;Cisco Systems NetFlow Services Export Version 9&quot;">RFC3954</a>] is used, and
   this protocol doesn't support variable-length Information Elements,
   then either multiple Template Records (one per applicationId length),
   or a single Template Record corresponding to the maximum sized
   applicationId MUST be used.

   Application IDs MAY be encoded in a smaller number of bytes,
   following the same rules as for IPFIX Reduced Size Encoding
   [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>].

   Application IDs MAY be encoded with a larger length.  For example, a
   normal IANA L3 protocol encoding would take 2 bytes since the
   Selector ID represents the protocol field from the IP header encoded
   in one byte.  However, an IANA L3 protocol encoding may be encoded
   with 3 bytes.  In this case, the Selector ID value MUST always be
   encoded in the least significant bits as shown in Figure 2.

    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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |Class. Eng. ID |zero-valued upper-bits ... Selector ID         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 2: Selector ID Encoding

<span class="h3"><a class="selflink" id="section-4.3" href="#section-4.3">4.3</a>.  Application Name Options Template Record</span>

   For Classification Engines that specify locally unique Application
   IDs (which means unique per engine and per router), an Options
   Template Record (see [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>]) MUST be used to export the
   correspondence between the Application ID, the Application Name, and
   the Application Description.

   For Classification Engines that specify globally unique Application
   IDs, an Options Template Record MAY be used to export the
   correspondence between the Application ID, the Application Name and
   the Application Description, unless the mapping is hardcoded in the
   Collector, or known out of band (for example, by polling a MIB).

   An example Options Template is shown in <a href="#section-6.8">Section 6.8</a>.

   Enterprises may assign company-wide Application ID values for the
   PANA-L7 Classification Engine.  In this case, a possible optimization
   for the Collector is to keep the mappings between the Application IDs
   and the Application Names per enterprise, as opposed to per Exporter.



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<span class="h3"><a class="selflink" id="section-4.4" href="#section-4.4">4.4</a>.  Resolving IANA L4 Port Discrepancies</span>

   Even though IANA L4 ports usually point to the same protocols for
   both UDP, TCP or other transport types, there are some exceptions, as
   mentioned in <a href="#appendix-B">Appendix B</a>.

   Instead of imposing the transport protocol (UDP/TCP/SCTP/etc.) in the
   scope of the "Application Name Options Template Record" (<a href="#section-6.8">Section 6.8</a>)
   for all applications (in addition to having the transport protocol as
   a key-field in the Flow Record definition), the convention is that
   the L4 application is always TCP related.  So, whenever the Collector
   has a conflict in looking up IANA, it would choose the TCP choice.
   As a result, the UDP L4 applications from Table 3 and the SCTP L4
   applications from Table 4 are assigned in the PANA_L7 Application ID
   range, i.e., under Classification Engine ID 13.

   Currently, there are no discrepancies between the well-known ports
   for TCP and the Datagram Congestion Control Protocol (DCCP).

<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>.  Grouping Applications with Attributes</span>

   Due to the high number of different Application IDs, Application IDs
   MAY be categorized into groups.  This offers the benefits of easier
   reporting and action, such as QoS policies.  Indeed, most
   applications with the same characteristics should be treated the same
   way; for example, all video traffic.

   Attributes are statically assigned per Application ID and are
   independent of the traffic.  The attributes are listed below:

      Name                   Description

      Category               An attribute that provides a first-
                             level categorization for each
                             Application ID.  Examples include
                             browsing, email, file-sharing,
                             gaming, instant messaging, voice-
                             and-video, etc.
                             The category attribute is encoded by
                             the applicationCategoryName
                             Information Element.

      Sub-Category           An attribute that provides a second-
                             level categorization for each
                             Application ID.  Examples include
                             backup-systems, client-server,
                             database, routing-protocol, etc.
                             The sub-category attribute is



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                             encoded by the
                             applicationSubCategoryName
                             Information Element.

      Application-           An attribute that groups multiple
      Group                  Application IDs that belong to the
                             same networking application.  For
                             example, the ftp-group contains
                             ftp-data (port 20), ftp (port 20),
                             ni-ftp (port 47), sftp (port 115),
                             bftp (port 152), ftp-agent(port
                             574), ftps-data (port 989).  The
                             application-group attribute is
                             encoded by the applicationGroupName
                             Information Element.

      P2P-Technology         Specifies if the Application ID is
                             based on peer-to-peer technology.
                             The P2P-technology attribute is
                             encoded by the p2pTechnology
                             Information Element.

      Tunnel-                Specifies if the Application ID is
      Technology             used as a tunnel technology.  The
                             tunnel-technology attribute is
                             encoded by the tunnelTechnology
                             Information Element.

      Encrypted              Specifies if the Application ID is
                             an encrypted networking protocol.
                             The encrypted attribute is encoded
                             by the encryptedTechnology
                             Information Element.

          Table 3: Application ID Static Attributes

   Every application is assigned to one applicationCategoryName, one
   applicationSubCategoryName, one applicationGroupName, and it has one
   p2pTechnology, one tunnelTechnology, and one encryptedTechnology.
   These new Information Elements are specified in the IANA
   Considerations section (<a href="#section-7.1">Section 7.1</a>).

   Maintaining the attribute values in IANA seems impossible to realize.
   Therefore, the attribute values per application are enterprise
   specific.






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<span class="h3"><a class="selflink" id="section-5.1" href="#section-5.1">5.1</a>.  Options Template Record for Attribute Values</span>

   An Options Template Record (see [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>]) SHOULD be used to export
   the correspondence between each Application ID and its related
   Attribute values.  An alternative way for the Collecting Process to
   learn the correspondence is to populate these mappings out of band,
   for example, by loading a CSV file containing the correspondence
   table.

   The Attributes Option Template contains the application ID as a scope
   field, followed by the applicationCategoryName, the
   applicationSubCategoryName, the applicationGroupName, the
   p2pTechnology, the tunnelTechnology, and the encryptedTechnology
   Information Elements.

   A list of attributes may conveniently be exported using a
   subTemplateList per [<a href="./rfc6313" title="&quot;Export of Structured Data in IP Flow Information Export (IPFIX)&quot;">RFC6313</a>].

   An example is given in <a href="#section-6.9">Section 6.9</a>.

<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>.  Application ID Examples</span>

   The following examples are created solely for the purpose of
   illustrating how the extensions proposed in this document are
   encoded.

<span class="h3"><a class="selflink" id="section-6.1" href="#section-6.1">6.1</a>.  Example 1: Layer 2 Protocol</span>

   The list of Classification Engine IDs in Table 1 shows that the layer
   2 Classification Engine IDs are 12 (PANA-L2), 18, (ETHERTYPE) and 19
   (LLC).

   From the Ethertype list, LLDP [<a href="#ref-LLDP" title="&quot;Standard for Local and metropolitan area networks - Station and Media Access Control Connectivity Discovery&quot;">LLDP</a>] has the Selector ID value
   0x88CC, so 35020 in decimal:

   NAME    Selector ID
   LLDP    35020

   So, in the case of LLDP, the Classification Engine ID is 18 (LLC)
   while the Selector ID has the value 35020.

   Per <a href="#section-4">Section 4</a>, the applicationId Information Element is a single
   field composed of 8 bits of Classification Engine ID, followed by n
   bits of Selector ID.  From Table 2, the Selector ID length n is 2 for
   the ETHERTYPE Engine ID.






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   Therefore, the Application ID is encoded as:

       0                   1                   2
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       18      |             35020             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   So the Application ID has the decimal value of 1214668.  The format
   '18..35020' is used for simplicity in the examples below, to clearly
   express that two components of the Application ID.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { applicationId='18..35020',
         octetTotalCount=123456 }

   The Collector has all the required information to determine that the
   application is LLDP, because the Application ID uses a global and
   well-known registry, i.e., the Ethertype.  The Collector can
   determine which application is represented by the Application ID by
   loading the registry out of band.

<span class="h3"><a class="selflink" id="section-6.2" href="#section-6.2">6.2</a>.  Example 2: Standardized IANA Layer 3 Protocol</span>

   From the list of Classification Engine IDs in Table 1, the IANA layer
   3 Classification Engine ID (IANA-L3) is 1.  From Table 2 the Selector
   ID length is 1 for the IANA-L3 Engine ID.

   From the list of IANA layer 3 protocols (see [<a href="#ref-IANA-PROTO" title="&quot;Protocol Numbers&quot;">IANA-PROTO</a>]), ICMP has
   the value 1:

   Decimal    Keyword    Protocol                   Reference
   1          ICMP       Internet Control           [<a href="./rfc792" title="&quot;Internet Control Message Protocol&quot;">RFC792</a>]
                          Message

   So, in the case of the standardized IANA layer 3 protocol ICMP, the
   Classification Engine ID is 1, and the Selector ID has the value of
   1.




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   Therefore, the Application ID is encoded as:

       0                   1
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       1       |       1       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   So, the Application ID has the value of 257.  The format '1..1'  is
   used for simplicity in the examples below.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - ipDiffServCodePoint (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         ipDiffServCodePoint=0,
         applicationId='1..1',
         octetTotalCount=123456 }

   The Collector has all the required information to determine that the
   application is ICMP, because the Application ID uses a global and
   well-known registry, i.e., the IANA L3 protocol number.

<span class="h3"><a class="selflink" id="section-6.3" href="#section-6.3">6.3</a>.  Example 3: Proprietary Layer 3 Protocol</span>

   Assume that an enterprise has specified a new layer 3 protocol called
   "foo".

   From the list of Classification Engine IDs in Table 1, the
   proprietary layer 3 Classification Engine ID (PANA-L3) is 2.  From
   Table 2 the Selector ID length is 1 for the PANA-L3 Engine ID.

   A global registry within the enterprise specifies that the "foo"
   protocol has the value 90:

   Protocol    Protocol ID
   foo         90



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   So, in the case of the layer 3 protocol foo specified by this
   enterprise, the Classification Engine ID is 2, and the Selector ID
   has the value of 90.

   Therefore, the Application ID is encoded as:

       0                   1
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       2       |       90      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   So the Application ID has the value of 602.  The format '2..90' is
   used for simplicity in the examples below.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - ipDiffServCodePoint (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         ipDiffServCodePoint=0,
         applicationId='2..90',
         octetTotalCount=123456 }

   Along with this Flow Record, a new Options Template Record would be
   exported, as shown in <a href="#section-6.8">Section 6.8</a>.

<span class="h3"><a class="selflink" id="section-6.4" href="#section-6.4">6.4</a>.  Example 4: Standardized IANA Layer 4 Port</span>

   From the list of Classification Engine IDs in Table 1, the IANA layer
   4 Classification Engine ID (IANA-L4) is 3.  From Table 2 the Selector
   ID length is 2 for the IANA-L4 Engine ID.

   From the list of IANA layer 4 ports (see [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>]), SNMP has the
   value 161:






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   Keyword    Decimal    Description
   snmp       161/tcp    SNMP
   snmp       161/udp    SNMP

   So, in the case of the standardized IANA layer 4 SNMP port, the
   Classification Engine ID is 3, and the Selector ID has the value of
   161.

   Therefore, the Application ID is encoded as:

       0                   1
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       3       |              161              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   So the Application ID has the value of 196769.  The format '3..161'
   is used for simplicity in the examples below.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - protocol (key field)
   - ipDiffServCodePoint (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         protocol=17, ipDiffServCodePoint=0,
         applicationId='3..161',
         octetTotalCount=123456 }

   The Collector has all the required information to determine that the
   application is SNMP, because the Application ID uses a global and
   well-known registry, i.e., the IANA L4 protocol number.

<span class="h3"><a class="selflink" id="section-6.5" href="#section-6.5">6.5</a>.  Example 5: Layer 7 Application</span>

   In this example, the Metering Process has observed some Webex
   traffic.




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   From the list of Classification Engine IDs in Table 1, the layer 7
   unique Classification Engine ID (PANA-L7) is 13.  From Table 2 the
   Selector ID length is 3 for the PANA-L7 Engine ID.

   Suppose that the Metering Process returns the ID 10000 for Webex
   traffic.

   So, in the case of this Webex application, the Classification Engine
   ID is 13 and the Selector ID has the value of 10000.

   Therefore, the Application ID is encoded as:

    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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |      13       |                     10000                     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   So the Application ID has the value of 218113808.  The format
   '13..10000' is used for simplicity in the examples below.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - ipDiffServCodePoint (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         ipDiffServCodePoint=0,
         applicationId='13..10000',
         octetTotalCount=123456 }

   The 10000 value is globally unique for the enterprise, so that the
   Collector can determine which application is represented by the
   Application ID by loading the registry out of band.

   Along with this Flow Record, a new Options Template Record would be
   exported, as shown in <a href="#section-6.8">Section 6.8</a>.





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<span class="h3"><a class="selflink" id="section-6.6" href="#section-6.6">6.6</a>.  Example 6: Layer 7 Application with Private Enterprise Number</span>
      (PEN)

   In this example, the layer 7 Webex traffic from Example 5 above have
   been classified by enterprise X.  The exported records have been
   received by enterprise Y's mediation device, which wishes to forward
   them to a top-level Collector.

   In order for the top-level Collector to know that the records were
   classified by enterprise X, the enterprise Y mediation device must
   report the records using the PANA-L7-PEN Classification Engine ID
   with enterprise X's Private Enterprise Number.

   The PANA-L7-PEN Classification Engine ID is 20, and enterprise X's
   Selector ID for Webex traffic has the value of 10000.  From Table 2
   the Selector ID length is 3 for the PANA-L7-PEN Engine ID.

   Therefore, the Application ID is encoded as:

    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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |      20       |               enterprise ID = X            ...|
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |...Ent.ID.contd|                     10000                     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The format '20..X..10000' is used for simplicity in the examples
   below.

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - ipDiffServCodePoint (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)

   For example, a Flow Record corresponding to the above Template Record
   may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         ipDiffServCodePoint=0,
         applicationId='20..X..10000',
         octetTotalCount=123456 }



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   The 10000 value is globally unique for enterprise X, so that the
   Collector can determine which application is represented by the
   Application ID by loading the registry out of band.

   Along with this Flow Record, a new Options Template Record would be
   exported, as shown in <a href="#section-6.8">Section 6.8</a>.

<span class="h3"><a class="selflink" id="section-6.7" href="#section-6.7">6.7</a>.  Example: Port Obfuscation</span>

   For example, an HTTP server might run on a TCP port 23 (assigned to
   telnet in [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>]).  If the Metering Process is capable of
   detecting HTTP in the same case, the Application ID representation
   must contain HTTP.  However, if the reporting application wants to
   determine whether or not the default HTTP port 80 or 8080 was used,
   the transport ports (sourceTransportPort and destinationTransportPort
   at [<a href="#ref-IANA-IPFIX" title="&quot;IP Flow Information Export (IPFIX) Entities&quot;">IANA-IPFIX</a>]) must also be exported in the corresponding IPFIX
   record.

   In the case of a standardized IANA layer 4 port, the Classification
   Engine ID (PANA-L4) is 3, and the Selector ID has the value of 80 for
   HTTP (see [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>]).  From Table 2 the Selector ID length is 2
   for the PANA-L4 Engine ID.

   Therefore, the Application ID is encoded as:

       0                   1                   2
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       3       |             80                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Exporting Process creates a Template Record with a few
   Information Elements: amongst other things, the Application ID.  For
   example:

   - sourceIPv4Address (key field)
   - destinationIPv4Address (key field)
   - protocol (key field)
   - destinationTransportPort (key field)
   - applicationId (key field)
   - octetTotalCount (non-key field)










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   For example, a Flow Record corresponding to the above
   Template Record may contain:

       { sourceIPv4Address=192.0.2.1,
         destinationIPv4Address=192.0.2.2,
         protocol=17,
         destinationTransportPort=23,
         applicationId='3..80',
         octetTotalCount=123456 }

   The Collector has all the required information to determine that the
   application is HTTP, but runs on port 23.

<span class="h3"><a class="selflink" id="section-6.8" href="#section-6.8">6.8</a>.  Example: Application Name Mapping Options Template</span>

   Along with the Flow Records shown in the above examples, a new
   Options Template Record should be exported to express the Application
   Name and Application Description associated with each Application ID.

   The Options Template Record contains the following Information
   Elements:

   1. Scope = applicationId.

          From <a href="./rfc5101">RFC 5101</a>: The scope, which is only available
          in the Options Template Set, gives the context of
          the reported Information Elements in the Data
          Records.

   2. applicationName.

   3. applicationDescription.

   The Options Data Record associated with the examples above
   would contain, for example:

       { scope=applicationId='2..90',
         applicationName="foo",
         applicationDescription="The foo protocol",

         scope=applicationId='13..10000',
         applicationName="webex",
         applicationDescription="Webex application" }

         scope=applicationId='20..X..10000',
         applicationName="webex",
         applicationDescription="Webex application" }




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   When combined with the example Flow Records above, these Options
   Template Records tell the Collector:

   1. A flow of 123456 bytes exists from sourceIPv4Address 192.0.2.1 to
      destinationIPv4address 192.0.2.2 with an applicationId of
      '12..90', which maps to the "foo" application.

   2. A flow of 123456 bytes exists from sourceIPv4Address 192.0.2.1 to
      destinationIPv4address 192.0.2.2 with an Application ID of
      '13..10000', which maps to the "Webex" application.

   3. A flow of 123456 bytes exists from sourceIPv4Address 192.0.2.1 to
      destinationIPv4address 192.0.2.2 with an Application ID of
      '20..PEN..10000', which maps to the "Webex" application, according
      to the application registry from the enterprise X.

<span class="h3"><a class="selflink" id="section-6.9" href="#section-6.9">6.9</a>.  Example: Attributes Values Options Template Record</span>

   Along with the Flow Records shown in the above examples, a new
   Options Template Record is exported to express the values of the
   different attributes related to the Application IDs.

   The Options Template Record would contain the following Information
   Elements:

   1. Scope = applicationId.

      From <a href="./rfc5101">RFC 5101</a>: The scope, which is only available in the Options
      Template Set, gives the context of the reported Information
      Elements in the Data Records.

   2. applicationCategoryName.

   3. applicationSubCategoryName.

   4. applicationGroupName

   5. p2pTechnology

   6. tunnelTechnology

   7. encryptedTechnology









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   The Options Data Record associated with the examples above would
   contain, for example:

       { scope=applicationId='2..90',
         applicationCategoryName="foo-category",
         applicationSubCategoryName="foo-subcategory",
         applicationGroupName="foo-group",
         p2pTechnology=NO
         tunnelTechnology=YES
         encryptedTechnology=NO

   When combined with the example Flow Records above, these Options
   Template Records tell the Collector:

   A flow of 123456 bytes exists from sourceIPv4Address 192.0.2.1 to
   destinationIPv4address 192.0.2.2 with a DSCP value of 0 and an
   applicationId of '12..90', which maps to the "foo" application.  This
   application can be characterized by the relevant attributes values.

<span class="h2"><a class="selflink" id="section-7" href="#section-7">7</a>.  IANA Considerations</span>

<span class="h3"><a class="selflink" id="section-7.1" href="#section-7.1">7.1</a>.  New Information Elements</span>

   This document specifies 10 new IPFIX Information Elements:
   applicationDescription, applicationId, applicationName,
   classificationEngineId, applicationCategoryName,
   applicationSubCategoryName, applicationGroupName, p2pTechnology,
   tunnelTechnology, and encryptedTechnology.

   The new Information Elements listed below have been added to the
   IPFIX Information Element registry at [<a href="#ref-IANA-IPFIX" title="&quot;IP Flow Information Export (IPFIX) Entities&quot;">IANA-IPFIX</a>].

<span class="h4"><a class="selflink" id="section-7.1.1" href="#section-7.1.1">7.1.1</a>.  applicationDescription</span>

   Name: applicationDescription
   Description:
     Specifies the description of an application.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 94
   Status: current










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<span class="h4"><a class="selflink" id="section-7.1.2" href="#section-7.1.2">7.1.2</a>.  applicationId</span>

   Name: applicationId
   Description:
     Specifies an Application ID.
   Abstract Data Type: octetArray
   Data Type Semantics: identifier
   Reference: See <a href="./rfc6759#section-4">Section&nbsp;4 of [RFC6759]</a>
   for the applicationId Information Element Specification.
   ElementId: 95
   Status: current

<span class="h4"><a class="selflink" id="section-7.1.3" href="#section-7.1.3">7.1.3</a>.  applicationName</span>

   Name: applicationName
   Description:
     Specifies the name of an application.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 96
   Status: current

<span class="h4"><a class="selflink" id="section-7.1.4" href="#section-7.1.4">7.1.4</a>.  classificationEngineId</span>

   Name: classificationEngineId
   Description:
    A unique identifier for the engine that determined the
    Selector ID.  Thus, the Classification Engine ID defines
    the context for the Selector ID.  The Classification
    Engine can be considered as a specific registry for
    application assignments.

    Initial values for this field are listed below.  Further
    values may be assigned by IANA in the Classification
    Engine IDs registry per <a href="#section-7.2">Section 7.2</a>.

         0 Invalid.

         1 IANA-L3: The Assigned Internet Protocol Number
           (layer 3 (L3)) is exported in the Selector ID.  See
           <a href="http://www.iana.org/assignments/protocol-numbers">http://www.iana.org/assignments/protocol-numbers</a>.

         2 PANA-L3: Proprietary layer 3 definition.  An
           enterprise can export its own layer 3 protocol
           numbers.  The Selector ID has a global significance
           for all devices from the same enterprise.





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         3 IANA-L4: The IANA layer 4 (L4) well-known port
           number is exported in the Selector ID.  See [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>].
           Note: as an IPFIX flow is unidirectional,
           it contains the destination port.

         4 PANA-L4: Proprietary layer 4 definition.  An
           enterprise can export its own layer 4 port
           numbers.  The Selector ID has global significance
           for devices from the same enterprise.  Example:
           IPFIX was pre-assigned port 4739 using the IANA
           early allocation process [<a href="./rfc4020" title="&quot;Early IANA Allocation of Standards Track Code Points&quot;">RFC4020</a>] years before the
           document was published as an RFC.  While waiting for
           the RFC and it associated IANA registration,
           Selector ID 4739 was used with this PANA-L4.

         5 Reserved

         6 USER-Defined: The Selector ID represents
           applications defined by the user (using CLI, GUI,
           etc.) based on the methods described in <a href="#section-2">Section 2</a>.
           The Selector ID has a local significance per
           device.

         7 Reserved

         8 Reserved

         9 Reserved

        10 Reserved

        11 Reserved

        12 PANA-L2: Proprietary layer 2 (L2) definition.  An
           enterprise can export its own layer 2 identifiers.
           The Selector ID represents the enterprise's unique
           global layer 2 applications.  The Selector ID has a
           global significance for all devices from the same
           enterprise.  Examples include the Cisco Subnetwork
           Access Protocol (SNAP).











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        13 PANA-L7: Proprietary layer 7 definition.  The
           Selector ID represents the enterprise's unique
           global ID for layer 7 applications.  The
           Selector ID has a global significance for all
           devices from the same enterprise.  This
           Classification Engine ID is used when the
           application registry is owned by the Exporter
           manufacturer (referred to as the "enterprise" in
           this document).

        14 Reserved

        15 Reserved

        16 Reserved

        17 Reserved

        18 ETHERTYPE: The Selector ID represents the well-
           known Ethertype.  See [<a href="#ref-ETHERTYPE">ETHERTYPE</a>].

        19 LLC: The Selector ID represents the well-known
           IEEE 802.2 Link Layer Control (LLC) Destination
           Service Access Point (DSAP).  See [<a href="#ref-LLC" title="&quot;LOGICAL LINK CONTROL (LLC) PUBLIC LISTING&quot;">LLC</a>].

        20 PANA-L7-PEN: Proprietary layer 7 definition,
           including a Private Enterprise Number (PEN) [<a href="#ref-IANA-PEN" title="&quot;PRIVATE ENTERPRISE NUMBERS&quot;">IANA-PEN</a>]
           to identify that the application registry being
           used is not owned by the Exporter manufacturer or to
           identify the original enterprise in the case of a
           mediator or 3rd party device.  The Selector ID represents
           the enterprise unique global ID for layer 7
           applications.  The Selector ID has a global
           significance for all devices from the same
           enterprise.

        Some values (5, 7, 8, 9, 10, 11, 14, 15, 16, and 17),
        are reserved to be compliant with existing
        implementations already using the
        classificationEngineId.

   Abstract Data Type: unsigned8
   Data Type Semantics: identifier
   ElementId: 101
   Status: current






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<span class="h4"><a class="selflink" id="section-7.1.5" href="#section-7.1.5">7.1.5</a>.  applicationCategoryName</span>

    Name: applicationCategoryName
    Description:
     An attribute that provides a first-level categorization for
     each Application Id.
    Abstract Data Type: string
    Data Type Semantics:
    ElementId: 372
    Status: current

<span class="h4"><a class="selflink" id="section-7.1.6" href="#section-7.1.6">7.1.6</a>.  applicationSubCategoryName</span>

   Name: applicationSubCategoryName
   Description:
    An attribute that provides a second-level categorization
    for each Application Id.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 373
   Status: current

<span class="h4"><a class="selflink" id="section-7.1.7" href="#section-7.1.7">7.1.7</a>.  applicationGroupName</span>

   Name: applicationGroupName
   Description:
    An attribute that groups multiple Application IDs that
    belong to the same networking application.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 374
   Status: current

<span class="h4"><a class="selflink" id="section-7.1.8" href="#section-7.1.8">7.1.8</a>.  p2pTechnology</span>

   Name: p2pTechnology
   Description:
    Specifies if the Application ID is based on peer-to-peer
    technology.  Possible values are { "yes", "y", 1 },
    { "no", "n", 2 }, and { "unassigned", "u", 0 }.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 288
   Status: current







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<span class="h4"><a class="selflink" id="section-7.1.9" href="#section-7.1.9">7.1.9</a>.  tunnelTechnology</span>

   Name: tunnelTechnology
   Description:
     Specifies if the Application ID is used as a tunnel technology.
     Possible values are { "yes", "y", 1 }, { "no", "n", 2 },
     and { "unassigned", "u", 0 }.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 289
   Status: current

<span class="h4"><a class="selflink" id="section-7.1.10" href="#section-7.1.10">7.1.10</a>.  encryptedTechnology</span>

   Name: encryptedTechnology
   Description:
    Specifies if the Application ID is an encrypted networking
    protocol.  Possible values are { "yes", "y", 1 },
    { "no", "n", 2 }, and { "unassigned", "u", 0 }.
   Abstract Data Type: string
   Data Type Semantics:
   ElementId: 290
   Status: current

<span class="h3"><a class="selflink" id="section-7.2" href="#section-7.2">7.2</a>.  Classification Engine ID Registry</span>

   The Information Element #101, named classificationEngineId, carries
   information about the context for the Selector ID, and can be
   considered as a specific registry for application assignments.  For
   ensuring extensibility of this information, IANA has created a new
   registry for Classification Engine IDs and filled it with the initial
   list from the description Information Element #101,
   classificationEngineId, along with their respective default lengths
   (Table 2 in this document).

   New assignments for Classification Engine IDs will be administered by
   IANA through Expert Review [<a href="./rfc5226" title="">RFC5226</a>], i.e., review by one of a group
   of experts designated by an IETF Area Director.  The group of experts
   must double-check the new definitions with already defined
   Classification Engine IDs for completeness, accuracy, and redundancy.
   The specification of Classification Engine IDs MUST be published
   using a well-established and persistent publication medium.

<span class="h2"><a class="selflink" id="section-8" href="#section-8">8</a>.  Security Considerations</span>

   The same security considerations as for the IPFIX protocol [<a href="./rfc5101" title="&quot;Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information&quot;">RFC5101</a>]
   apply.  The IPFIX extension specified in this memo allows to identify
   what applications are used on the network.  Consequently, it is



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   possible to identify what applications are being used by the users,
   potentially threatening the privacy of those users, if not handled
   with great care.

   As mentioned in <a href="#section-1.1">Section 1.1</a>, the application knowledge is useful in
   security based applications.  Security applications may impose
   supplementary requirements on the export of application information,
   and these need to be examined on a case by case basis.

<span class="h2"><a class="selflink" id="section-9" href="#section-9">9</a>.  References</span>

<span class="h3"><a class="selflink" id="section-9.1" href="#section-9.1">9.1</a>.  Normative References</span>

   [<a id="ref-ETHERTYPE">ETHERTYPE</a>]  IEEE, &lt;<a href="http://standards.ieee.org/develop/regauth/ethertype/eth.txt">http://standards.ieee.org/develop/regauth/</a>
                <a href="http://standards.ieee.org/develop/regauth/ethertype/eth.txt">ethertype/eth.txt</a>&gt;.

   [<a id="ref-IANA-PEN">IANA-PEN</a>]   IANA, "PRIVATE ENTERPRISE NUMBERS",
                &lt;<a href="http://www.iana.org/assignments/enterprise-numbers">http://www.iana.org/assignments/enterprise-numbers</a>&gt;.

   [<a id="ref-IANA-PORTS">IANA-PORTS</a>] IANA, "Service Name and Transport Protocol Port Number
                Registry",
                &lt;<a href="http://www.iana.org/assignments/port-numbers">http://www.iana.org/assignments/port-numbers</a>&gt;.

   [<a id="ref-IANA-PROTO">IANA-PROTO</a>] IANA, "Protocol Numbers",
                &lt;<a href="http://www.iana.org/assignments/protocol-numbers">http://www.iana.org/assignments/protocol-numbers</a>&gt;.

   [<a id="ref-LLC">LLC</a>]        IEEE, "LOGICAL LINK CONTROL (LLC) PUBLIC LISTING",
                &lt;<a href="http://standards.ieee.org">http://standards.ieee.org</a> /develop/regauth/llc
                /public.html&gt;.

   [<a id="ref-RFC2119">RFC2119</a>]    Bradner, S., "Key words for use in RFCs to Indicate
                Requirement Levels", <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a>, March 1997.

   [<a id="ref-RFC5101">RFC5101</a>]    Claise, B., Ed., "Specification of the IP Flow
                Information Export (IPFIX) Protocol for the Exchange of
                IP Traffic Flow Information", <a href="./rfc5101">RFC 5101</a>, January 2008.

   [<a id="ref-RFC5102">RFC5102</a>]    Quittek, J., Bryant, S., Claise, B., Aitken, P., and J.
                Meyer, "Information Model for IP Flow Information
                Export", <a href="./rfc5102">RFC 5102</a>, January 2008.

   [<a id="ref-RFC5226">RFC5226</a>]    Narten, T. and H. Alvestrand, "Guidelines for Writing an
                IANA Considerations Section in RFCs", <a href="https://www.rfc-editor.org/bcp/bcp26">BCP 26</a>, <a href="./rfc5226">RFC 5226</a>,
                May 2008.







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<span class="h3"><a class="selflink" id="section-9.2" href="#section-9.2">9.2</a>.  Informative References</span>

   [<a id="ref-CISCO-APPLICATION-REGISTRY">CISCO-APPLICATION-REGISTRY</a>]
                Cisco, "Application Registry",
                &lt;<a href="http://www.cisco.com/go/application_registry">http://www.cisco.com/go/application_registry</a>&gt;.

   [<a id="ref-IANA-IPFIX">IANA-IPFIX</a>] IANA, "IP Flow Information Export (IPFIX) Entities",
                &lt;<a href="http://www.iana.org/assignments/ipfix">http://www.iana.org/assignments/ipfix</a>&gt;.

   [<a id="ref-LLDP">LLDP</a>]       IEEE, Std 802.1AB-2005, "Standard for Local and
                metropolitan area networks - Station and Media Access
                Control Connectivity Discovery", IEEE Std 802.1AB-2005
                IEEE Std, 2005.

   [<a id="ref-RFC792">RFC792</a>]     Postel, J., "Internet Control Message Protocol", STD 5,
                <a href="./rfc792">RFC 792</a>, September 1981.

   [<a id="ref-RFC3917">RFC3917</a>]    Quittek, J., Zseby, T., Claise, B., and S. Zander,
                "Requirements for IP Flow Information Export (IPFIX)",
                <a href="./rfc3917">RFC 3917</a>, October 2004.

   [<a id="ref-RFC3954">RFC3954</a>]    Claise, B., Ed., "Cisco Systems NetFlow Services Export
                Version 9", <a href="./rfc3954">RFC 3954</a>, October 2004.

   [<a id="ref-RFC4020">RFC4020</a>]    Kompella, K. and A. Zinin, "Early IANA Allocation of
                Standards Track Code Points", <a href="https://www.rfc-editor.org/bcp/bcp100">BCP 100</a>, <a href="./rfc4020">RFC 4020</a>,
                February 2005.

   [<a id="ref-RFC5103">RFC5103</a>]    Trammell, B. and E. Boschi, "Bidirectional Flow Export
                Using IP Flow Information Export (IPFIX)", <a href="./rfc5103">RFC 5103</a>,
                January 2008.

   [<a id="ref-RFC5470">RFC5470</a>]    Sadasivan, G., Brownlee, N., Claise, B., and J. Quittek,
                "Architecture for IP Flow Information Export", <a href="./rfc5470">RFC 5470</a>,
                March 2009.

   [<a id="ref-RFC5471">RFC5471</a>]    Schmoll, C., Aitken, P., and B. Claise, "Guidelines for
                IP Flow Information Export (IPFIX) Testing", <a href="./rfc5471">RFC 5471</a>,
                March 2009.

   [<a id="ref-RFC5473">RFC5473</a>]    Boschi, E., Mark, L., and B. Claise, "Reducing
                Redundancy in IP Flow Information Export (IPFIX) and
                Packet Sampling (PSAMP) Reports", <a href="./rfc5473">RFC 5473</a>, March 2009.

   [<a id="ref-RFC5476">RFC5476</a>]    Claise, B., Ed., Johnson, A., and J. Quittek, "Packet
                Sampling (PSAMP) Protocol Specifications", <a href="./rfc5476">RFC 5476</a>,
                March 2009.




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   [<a id="ref-RFC5477">RFC5477</a>]    Dietz, T., Claise, B., Aitken, P., Dressler, F., and G.
                Carle, "Information Model for Packet Sampling Exports",
                <a href="./rfc5477">RFC 5477</a>, March 2009.

   [<a id="ref-RFC5353">RFC5353</a>]    Xie, Q., Stewart, R., Stillman, M., Tuexen, M., and A.
                Silverton, "Endpoint Handlespace Redundancy Protocol
                (ENRP)", <a href="./rfc5353">RFC 5353</a>, September 2008.

   [<a id="ref-RFC5811">RFC5811</a>]    Hadi Salim, J. and K. Ogawa, "SCTP-Based Transport
                Mapping Layer (TML) for the Forwarding and Control
                Element Separation (ForCES) Protocol", <a href="./rfc5811">RFC 5811</a>, March
                2010.

   [<a id="ref-RFC6183">RFC6183</a>]    Kobayashi, A., Claise, B., Muenz, G., and K. Ishibashi,
                "IP Flow Information Export (IPFIX) Mediation:
                Framework", <a href="./rfc6183">RFC 6183</a>, April 2011.

   [<a id="ref-RFC6313">RFC6313</a>]    Claise, B., Dhandapani, G., Aitken, P., and S. Yates,
                "Export of Structured Data in IP Flow Information Export
                (IPFIX)", <a href="./rfc6313">RFC 6313</a>, July 2011.

<span class="h2"><a class="selflink" id="section-10" href="#section-10">10</a>.  Acknowledgements</span>

   The authors would like to thank their many colleagues across Cisco
   Systems who made this work possible.  Specifically, Patrick Wildi for
   his time and expertise.

























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<span class="h2"><a class="selflink" id="appendix-A" href="#appendix-A">Appendix A</a>.  Additions to XML Specification of IPFIX Information</span>
             Elements (Non-normative)

   This appendix contains additions to the machine-readable description
   of the IPFIX information model coded in XML in <a href="#appendix-A">Appendix A</a> and
   <a href="./rfc5102#appendix-B">Appendix&nbsp;B in [RFC5102]</a>.  Note that this appendix is of informational
   nature, while the text in <a href="#section-7">Section 7</a> (generated from this appendix) is
   normative.

   The following field definitions are appended to the IPFIX information
   model in <a href="./rfc5102#appendix-A">Appendix&nbsp;A of [RFC5102]</a>.

     &lt;field name="applicationDescription"
            dataType="string"
            group="application"
            elementId="94" applicability="all"
   status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies the description of an application.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="applicationId"
            dataType="octetArray"
            group="application"
            dataTypeSemantics="identifier"
            elementId="95" applicability="all"
   status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies an Application ID.
         &lt;/paragraph&gt;
       &lt;/description&gt;
       &lt;reference&gt;
         &lt;paragraph&gt;
            See <a href="./rfc6759#section-4">Section&nbsp;4 of [RFC6759]</a>
           for the applicationId Information Element
           Specification.
         &lt;/paragraph&gt;
       &lt;/reference&gt;
     &lt;/field&gt;

     &lt;field name="applicationName"
            dataType="string"
            group="application"
            elementId="96" applicability="all"



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   status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies the name of an application.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="classificationEngineId"
            dataType="unsigned8"
            group="application"
            dataTypeSemantics="identifier"
            elementId="101" applicability="all"
   status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
           0 Invalid.

           1 IANA-L3: The Assigned Internet Protocol Number
             (layer 3 (L3)) is exported in the Selector ID.
             See <a href="http://www.iana.org/assignments/protocol-numbers">http://www.iana.org/assignments/protocol-</a>
             <a href="http://www.iana.org/assignments/protocol-numbers">numbers</a>.

           2 PANA-L3: Proprietary layer 3 definition.  An
             enterprise can export its own layer 3 protocol
             numbers.  The Selector ID has a global
             significance for all devices from the same
             enterprise.

           3 IANA-L4: The IANA layer 4 (L4) well-known port
             number is exported in the Selector ID.  See
             [<a href="#ref-IANA-PORTS" title="&quot;Service Name and Transport Protocol Port Number Registry&quot;">IANA-PORTS</a>].  Note: as an IPFIX flow is
             unidirectional, it contains the destination
             port.

           4 PANA-L4: Proprietary layer 4 definition.  An
             enterprise can export its own layer 4 port
             numbers.  The Selector ID has global
             significance for devices from the same
             enterprise.  Example: IPFIX was pre-assigned
             port 4739 using the IANA early allocation
             process [<a href="./rfc4020" title="&quot;Early IANA Allocation of Standards Track Code Points&quot;">RFC4020</a>] years before the document was
             published as an RFC.  While waiting for the
             RFC and its associated IANA registration,
             Selector ID 4739 was used with this PANA-L4.

           5 Reserved




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           6 USER-Defined: The Selector ID represents
             applications defined by the user (using CLI,
             GUI, etc.) based on the methods described in
             <a href="#section-2">Section 2</a>.  The Selector ID has a local
             significance per device.

           7 Reserved

           8 Reserved

           9 Reserved

          10 Reserved

          11 Reserved

          12 PANA-L2: Proprietary layer 2 (L2) definition.
             An enterprise can export its own layer 2
             identifiers.  The Selector ID represents the
             enterprise's unique global layer 2
             applications.  The Selector ID has a global
             significance for all devices from the same
             enterprise.  Examples include the Cisco Subnetwork
             Access Protocol (SNAP).

          13 PANA-L7: Proprietary layer 7 definition.  The
             Selector ID represents the enterprise's unique
             global ID for layer 7 applications.  The
             Selector ID has a global significance for all
             devices from the same enterprise.  This
             Classification Engine ID is used when the
             application registry is owned by the Exporter
             manufacturer (referred to as the "enterprise"
             in this document).

          14 Reserved

          15 Reserved

          16 Reserved

          17 Reserved

          18 ETHERTYPE: The Selector ID represents the
             well-known Ethertype.  See [<a href="#ref-ETHERTYPE">ETHERTYPE</a>].

          19 LLC: The Selector ID represents the well-known
             IEEE 802.2 Link Layer Control (LLC)



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             Destination Service Access Point (DSAP).  See
             [<a href="#ref-LLC" title="&quot;LOGICAL LINK CONTROL (LLC) PUBLIC LISTING&quot;">LLC</a>].

          20 PANA-L7-PEN: Proprietary layer 7 definition,
             including a Private Enterprise Number (PEN)
             [<a href="#ref-IANA-PEN" title="&quot;PRIVATE ENTERPRISE NUMBERS&quot;">IANA-PEN</a>] to identify that the application
             registry being used is not owned by the
             Exporter manufacturer or to identify the
             original enterprise in the case of a mediator
             or 3rd party device.  The Selector ID represents
             the enterprise unique global ID for layer 7
             applications.  The Selector ID has a global
             significance for all devices from the same
             enterprise.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="applicationCategoryName"
            dataType="string"
            group="application"
            elementId="372"
            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            An attribute that provides a first-level categorization
            for each Application Id.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="applicationSubCategoryName"
            dataType="string"
            group="application"
            elementId="373"
            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            An attribute that provides a second-level
            categorization for each Application ID.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="applicationGroupName"
            dataType="string"



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            group="application"
            elementId="374"
            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            An attribute that groups multiple Application IDs
            that belong to the same networking application.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="p2pTechnology"
            dataType="string"
            group="application"
            elementId="288"
            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies if the Application ID is based on peer-
            to-peer technology.  Possible values are
            { "yes", "y", 1 }, { "no", "n", 2 }, and
            { "unassigned", "u", 0 }.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="tunnelTechnology"
            dataType="string"
            group="application"
            elementId="289"
            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies if the Application ID is used as a
            tunnel technology.  Possible values are
            { "yes", "y", 1 }, { "no", "n", 2 }, and
            { "unassigned", "u", 0 }.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

     &lt;field name="encryptedTechnology"
            dataType="string"
            group="application"
            elementId="290"



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            applicability="all"
            status="current"&gt;
       &lt;description&gt;
         &lt;paragraph&gt;
            Specifies if the Application ID is an encrypted
            networking protocol.  Possible values are
            { "yes", "y", 1 }, { "no", "n", 2 }, and
            { "unassigned", "u", 0 }.
         &lt;/paragraph&gt;
       &lt;/description&gt;
     &lt;/field&gt;

<span class="h2"><a class="selflink" id="appendix-B" href="#appendix-B">Appendix B</a>.  Port Collisions Tables (Non-normative)</span>

   The following table lists the 10 ports that have different protocols
   assigned for TCP and UDP (at the time of writing this document):

       exec            512/tcp    remote process execution;
                                  authentication performed
                                  using passwords and UNIX
                                  login names

       comsat/biff     512/udp    used by mail system to
                                  notify users of new mail
                                  received; currently
                                  receives messages only from
                                  processes on the same
                                  machine

       login           513/tcp    remote login a la telnet;
                                  automatic authentication
                                  performed based on
                                  priviledged [sic] port numbers
                                  and distributed data bases
                                  which identify
                                  "authentication domains"

       who             513/udp    maintains data bases
                                  showing who's logged in to
                                  machines on a local
                                  net and the load average of
                                  the machine

       shell           514/tcp    cmd
                                  like exec, but automatic
                                  authentication is performed
                                  as for login server




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       syslog          514/udp

       oob-ws-https    664/tcp    DMTF out-of-band secure web
                                  services management
                                  protocol
                                  Jim Davis
                                  &lt;jim.davis@wbemsolutions.com&gt;

       asf-secure-rmcp 664/udp    ASF Secure Remote
                                  Management and Control
                                  Protocol

       rfile           750/tcp
       kerberos-iv     750/udp    kerberos version iv

       submit          773/tcp
       notify          773/udp

       rpasswd         774/tcp
       acmaint_dbd     774/udp

       entomb          775/tcp
       acmaint_transd  775/udp

       busboy          998/tcp
       puparp          998/udp

       garcon          999/tcp
       applix          999/udp    Applix ac

           Table 4: Different Protocols on UDP and TCP

   The following table lists the 19 ports that have different protocols
   assigned for TCP and SCTP (at the time of writing this document):

       #               3097/tcp    Reserved

       itu-bicc-stc    3097/sctp   ITU-T Q.1902.1/Q.2150.3
                                   Greg Sidebottom
                                   &lt;gregside@home.com&gt;

       #               5090/tcp    &lt;not assigned&gt;

       car             5090/sctp   Candidate AR

       #               5091/tcp    &lt;not assigned&gt;

       cxtp            5091/sctp   Context Transfer Protocol



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       #               6704/tcp    Reserved

       frc-hp          6704/sctp   ForCES HP (High Priority)
                                   channel [<a href="./rfc5811" title="&quot;SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol&quot;">RFC5811</a>]

       #               6705/tcp    Reserved

       frc-mp          6705/sctp   ForCES MP (Medium
                                   Priority) channel
                                   [<a href="./rfc5811" title="&quot;SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol&quot;">RFC5811</a>]

       #               6706/tcp    Reserved

       frc-lp          6706/sctp   ForCES LP (Low Priority)
                                   channel [<a href="./rfc5811" title="&quot;SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol&quot;">RFC5811</a>]

       #               9082/tcp    &lt;not assigned&gt;

       lcs-ap          9082/sctp   LCS Application Protocol
                                   Kimmo Kymalainen
                                   &lt;kimmo.kymalainen@etsi.org&gt;

       #               9902/tcp    &lt;not assigned&gt;

       enrp-sctp-tls   9902/sctp   enrp/tls server channel
                                   [<a href="./rfc5353" title="&quot;Endpoint Handlespace Redundancy Protocol (ENRP)&quot;">RFC5353</a>]

       #               11997/tcp   &lt;not assigned&gt;
       #               11998/tcp   &lt;not assigned&gt;
       #               11999/tcp   &lt;not assigned&gt;

       wmereceiving    11997/sctp  WorldMailExpress
       wmedistribution 11998/sctp  WorldMailExpress
       wmereporting    11999/sctp  WorldMailExpress
                                Greg Foutz
                                   &lt;gregf@adminovation.com&gt;

       #               25471/tcp   &lt;not assigned&gt;

       rna             25471/sctp  RNSAP User Adaptation for
                                   Iurh
                                   Dario S. Tonesi
                                   &lt;dario.tonesi@nsn.com&gt;
                                   07 February 2011

       #               29118/tcp   Reserved

       sgsap           29118/sctp  SGsAP in 3GPP



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       #               29168/tcp   Reserved

       sbcap           29168/sctp  SBcAP in 3GPP

       #               29169/tcp   &lt;not assigned&gt;

       iuhsctpassoc    29169/sctp  HNBAP and RUA Common
                                   Association
                                   John Meredith
                                   &lt;John.Meredith@etsi.org&gt;
                                   08 September 2009

       #               36412/tcp   &lt;not assigned&gt;

       s1-control      36412/sctp  S1-Control Plane (3GPP)
                                   Kimmo Kymalainen
                                   &lt;kimmo.kymalainen@etsi.org&gt;
                                   01 September 2009

       #               36422/tcp   &lt;not assigned&gt;

       x2-control      36422/sctp  X2-Control Plane (3GPP)
                                   Kimmo Kymalainen
                                  &lt;kimmo.kymalainen@etsi.org&gt;
                                   01 September 2009

       #               36443/tcp   &lt;not assigned&gt;

       m2ap            36443/sctp  M2 Application Part
                                   Dario S. Tonesi
                                   &lt;dario.tonesi@nsn.com&gt;
                                   07 February 2011

       #               36444/tcp   &lt;not assigned&gt;

       m3ap            36444/sctp  M3 Application Part
                                   Dario S. Tonesi
                                   &lt;dario.tonesi@nsn.com&gt;
                                   07 February 2011

          Table 5: Different Protocols on SCTP and TCP

<span class="h2"><a class="selflink" id="appendix-C" href="#appendix-C">Appendix C</a>. Application Registry Example (Non-normative)</span>

   A reference to the Cisco Systems assigned numbers for the Application
   ID and the different attribute assignments can be found at
   [<a href="#ref-CISCO-APPLICATION-REGISTRY">CISCO-APPLICATION-REGISTRY</a>].




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Authors' Addresses

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

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


   Paul Aitken
   Cisco Systems, Inc.
   96 Commercial Quay
   Commercial Street
   Edinburgh, EH6 6LX
   United Kingdom

   Phone: +44 131 561 3616
   EMail: paitken@cisco.com


   Nir Ben-Dvora
   Cisco Systems, Inc.
   32 HaMelacha St.,
   P.O. Box 8735, I.Z.Sapir
   South Netanya, 42504
   Israel

   Phone: +972 9 892 7187
   EMail: nirbd@cisco.com



















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