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RFC 5388

 
 
 

Information Model and XML Data Model for Traceroute Measurements

Part 2 of 3, p. 23 to 46
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6.  Data Model for Storing Traceroute Measurements

   For storing and transmitting information according to the information
   model defined in the previous section, a data model is required that
   specifies how to encode the elements of the information model.

   There are several design choices for a data model.  It can use a
   binary or textual representation and it can be defined from scratch
   or use already existing frameworks and data models.  In general, the
   use of already existing frameworks and models should be preferred.

   Binary and textual representations both have advantages and
   disadvantages.  Textual representations are (with some limitations)
   human-readable, while a binary representation consumes less resources
   for storing, transmitting, and parsing data.

   An already existing and closely related data model is the DISMAN-
   TRACEROUTE-MIB module [RFC4560], which specifies a Structure of
   Management Information version 2 (SMIv2) encoding [RFC2578],
   [RFC2579], and [RFC2580] for transmitting traceroute measurement
   information (configuration and results).  This data model is well
   suited and supported within network management systems, but as a
   general format for storing and transmitting traceroute results, it is
   not easily applicable.

   Another binary representation would be an extension of traffic-flow
   information encodings as specified for the IP Flow Information Export
   (IPFIX) protocol [RFC5101], [RFC5102].  The IPFIX protocol is
   extensible.  However, the architecture behind this protocol [IPFIX]
   is targeted at exporting passively measured flow information.
   Therefore, some obstacles are expected when trying to use it for
   transmitting traceroute measurement information.

   For textual representations, using the eXtensible Markup Language
   (XML) [W3C.REC-xml-20060816] is an obvious choice.  XML supports
   clean structuring of data and syntax checking of records.  With some

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   limitations, it is human-readable.  It is supported well by a huge
   pool of tools and standards for generating, transmitting, parsing,
   and converting it to other data formats.  Its disadvantages are the
   resource consumption for processing, storing, and transmitting
   information.  Since the expected data volumes related to traceroute
   measurement in network operation and maintenance are not expected to
   be extremely high, the inefficient usage of resources is not a
   significant disadvantage.  Therefore, XML was chosen as a basis for
   the traceroute measurement information model that is specified in
   this memo.

   Section 7 contains the XML schema to be used as a template for
   storing and/or exchanging traceroute measurement information.  The
   schema was designed in order to use an extensible approach based on
   templates (pretty similar to how the IPFIX protocol is designed)
   where the traceroute configuration elements (both the requested
   parameters, "RequestMetadata", and the actual parameters used,
   "MeasurementMetadata") are metadata to be referenced by results
   information elements (data) by means of the "TestName" element (used
   as a unique identifier, chosen in accordance to the specification of
   [RFC4560]).  Currently Open Grid Forum (OGF) is also using this
   approach and cross-requirements have been analyzed.  As a result of
   this analysis, the XML schema contained in Section 7 is compatible
   with the OGF schema since both were designed in a way that limits the
   unnecessary redundancy and a simple one-to-one transformation between
   the two exists.

7.  XML Schema for Traceroute Measurements

   This section presents the XML schema to be used as a template for
   storing and/or exchanging traceroute measurement information.  The
   schema uses UTF-8 encoding as defined in [RFC3629].  In documents
   conforming to the format presented here, an XML declaration SHOULD be
   present specifying the version and the character encoding of the XML
   document.  The document should be encoded using UTF-8.  Since some of
   the strings can span multiple lines, [RFC5198] applies.  XML
   processing instructions and comments MUST be ignored.  Mind that
   whitespace is significant in XML when writing documents conforming to
   this schema.  Documents using the presented format must be valid
   according to the XML schema shown in this section.  Since elements of
   type "_CtlType" may contain elements from unknown namespaces, those
   elements MUST be ignored if their namespace is unknown to the
   processor.  Values for elements using the XML schema type "dateTime"
   MUST be restricted to values defined in [RFC3339].  Future versions
   of this format MAY extend this schema by creating a new schema that
   redefines all or some of the data types and elements defined in this
   version or by establishing a complete new schema.

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   Due to the limited line length some lines appear wrapped.

 <?xml version="1.0" encoding="UTF-8"?>
 <xs:schema elementFormDefault="qualified"
            targetNamespace="urn:ietf:params:xml:ns:traceroute-1.0"
            xmlns:xs="http://www.w3.org/2001/XMLSchema"
            xmlns:tr="urn:ietf:params:xml:ns:traceroute-1.0">
   <xs:simpleType name="string255">
     <xs:annotation>
       <xs:documentation>String restricted to 255
       characters.</xs:documentation>
     </xs:annotation>

     <xs:restriction base="xs:string">
       <xs:maxLength value="255"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="u8nonzero">
     <xs:annotation>
       <xs:documentation>unsignedByte with non zero
       value.</xs:documentation>
     </xs:annotation>

     <xs:restriction base="xs:unsignedByte">
       <xs:minInclusive value="1"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:complexType name="_roundTripTime">
     <xs:choice>
       <xs:element name="roundTripTime">
         <xs:simpleType>
           <xs:restriction base="xs:unsignedInt"/>
         </xs:simpleType>
       </xs:element>

       <xs:element name="roundTripTimeNotAvailable">
         <xs:complexType/>
       </xs:element>
     </xs:choice>
   </xs:complexType>

   <xs:complexType name="_inetAddressUnknown"/>

   <xs:simpleType name="_inetAddressIpv4">
     <xs:restriction base="xs:string">
       <xs:pattern value="(([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5

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 ]).){3}([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="_inetAddressIpv6">
     <xs:restriction base="xs:string">
       <xs:pattern value="(([\dA-Fa-f]{1,4}:){7}[\dA-Fa-f]{1,4})(:([\d
 ]{1,3}.){3}[\d]{1,3})?"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="_inetAddressDns">
     <xs:restriction base="xs:string">
       <xs:maxLength value="256"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:complexType name="_inetAddressASNumber">
     <xs:annotation>
       <xs:documentation>Specifies the AS number of a hop in the
       traceroute path as a 32-bit number and indicates how the
       mapping from IP address to AS number was
       performed.</xs:documentation>
     </xs:annotation>

     <xs:sequence>
       <xs:element name="asNumber" type="xs:unsignedInt"/>

       <xs:element name="ipASNumberMappingType">
         <xs:simpleType>
           <xs:restriction base="xs:string">
             <xs:enumeration value="bgptables"/>

             <xs:enumeration value="routingregistries"/>

             <xs:enumeration value="nslookup"/>

             <xs:enumeration value="others"/>

             <xs:enumeration value="unknown"/>
           </xs:restriction>
         </xs:simpleType>
       </xs:element>
     </xs:sequence>
   </xs:complexType>

   <xs:complexType name="inetAddress">
     <xs:choice>

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       <xs:element name="inetAddressUnknown"
                   type="tr:_inetAddressUnknown"/>

       <xs:element name="inetAddressIpv4" type="tr:_inetAddressIpv4"/>

       <xs:element name="inetAddressIpv6" type="tr:_inetAddressIpv6"/>

       <xs:element name="inetAddressASNumber"
                   type="tr:_inetAddressASNumber"/>

       <xs:element minOccurs="0" name="inetAddressDns"
                   type="tr:_inetAddressDns"/>
     </xs:choice>
   </xs:complexType>

   <xs:complexType name="inetAddressWithoutDns">
     <xs:sequence>
       <xs:choice>
         <xs:element name="inetAddressUnknown"
                     type="tr:_inetAddressUnknown"/>

         <xs:element name="inetAddressIpv4"
                     type="tr:_inetAddressIpv4"/>

         <xs:element name="inetAddressIpv6"
                     type="tr:_inetAddressIpv6"/>

         <xs:element name="inetAddressASNumber"
                     type="tr:_inetAddressASNumber"/>
       </xs:choice>
     </xs:sequence>
   </xs:complexType>

   <xs:simpleType name="operationResponseStatus">
     <xs:restriction base="xs:string">
       <xs:enumeration value="responseReceived"/>

       <xs:enumeration value="unknown"/>

       <xs:enumeration value="internalError"/>

       <xs:enumeration value="requestTimedOut"/>

       <xs:enumeration value="unknownDestinationAddress"/>

       <xs:enumeration value="noRouteToTarget"/>

       <xs:enumeration value="interfaceInactiveToTarget"/>

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       <xs:enumeration value="arpFailure"/>

       <xs:enumeration value="maxConcurrentLimitReached"/>

       <xs:enumeration value="unableToResolveDnsName"/>

       <xs:enumeration value="invalidHostAddress"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:complexType name="_CtlType">
     <xs:choice>
       <xs:element name="TCP">
         <xs:complexType/>
       </xs:element>

       <xs:element name="UDP">
         <xs:complexType/>
       </xs:element>

       <xs:element name="ICMP">
         <xs:complexType/>
       </xs:element>

       <xs:any namespace="##other"/>
     </xs:choice>
   </xs:complexType>

   <xs:complexType name="_ProbeResults">
     <xs:sequence>
       <xs:element maxOccurs="255" name="hop">
         <xs:complexType>
           <xs:sequence>
             <xs:element maxOccurs="10" name="probe">
               <xs:complexType>
                 <xs:sequence>
                   <xs:element name="HopAddr"
                               type="tr:inetAddressWithoutDns">
                     <xs:annotation>
                       <xs:documentation>Specifies the address of a
                       hop in the traceroute measurement path.  This
                       object is not allowed to be a DNS name.  The
                       address type can be determined by examining the
                       "inetAddress" type name and the corresponding
                       element value.</xs:documentation>
                     </xs:annotation>
                   </xs:element>

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                   <xs:element minOccurs="0" name="HopName"
                               type="tr:_inetAddressDns">
                     <xs:annotation>
                       <xs:documentation>Specifies the DNS name of
                       the "HopAddr" if it is available.  If it is
                       not available, the element is
                       omitted.</xs:documentation>
                     </xs:annotation>
                   </xs:element>

                   <xs:element maxOccurs="255" minOccurs="0"
                               name="MPLSLabelStackEntry">
                     <xs:annotation>
                       <xs:documentation>Specifies entries of the
                       MPLS label stack of a probe observed when the
                       probe arrived at the hop that replied to the
                       probe.  This object contains one MPLS label stack
                       entry as a 32-bit value as it is observed on the
                       MPLS label stack.  Contained in this single
                       number are the MPLS label, the Exp field, the S
                       flag, and the MPLS TTL value as specified in
                       [RFC3032].  If more than one MPLS label stack
                       entry is reported, then multiple instances of
                       elements of this type are used.  They must be
                       ordered in the same order as on the label stack
                       with the top label stack entry being reported
                       first.</xs:documentation>
                     </xs:annotation>

                     <xs:simpleType>
                       <xs:restriction base="xs:unsignedInt">
                         <xs:maxInclusive value="4294967295"/>
                       </xs:restriction>
                     </xs:simpleType>
                   </xs:element>

                   <xs:element name="ProbeRoundTripTime"
                               type="tr:_roundTripTime">
                     <xs:annotation>
                       <xs:documentation>If this element contains the
                       element "roundTripTime", this specifies the
                       amount of time measured in milliseconds from
                       when a probe was sent to when its response was
                       received or when it timed out.  The value of
                       this element is reported as the truncation of
                       the number reported by the traceroute tool (the
                       output "&lt; 1 ms" is therefore encoded as 0 ms).
                       If it contains the element

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                       "roundTripTimeNotAvailable", it means either
                       the probe was lost because of a timeout or it
                       was not possible to transmit a probe.
                       </xs:documentation>
                     </xs:annotation>
                   </xs:element>

                   <xs:element name="ResponseStatus"
                               type="tr:operationResponseStatus">
                     <xs:annotation>
                       <xs:documentation>Specifies the result of a
                       traceroute measurement made by the host for a
                       particular probe.</xs:documentation>
                     </xs:annotation>
                   </xs:element>

                   <xs:element name="Time" type="xs:dateTime">
                     <xs:annotation>
                       <xs:documentation>Specifies the timestamp for
                       the time the response to the probe was
                       received at the interface.</xs:documentation>
                     </xs:annotation>
                   </xs:element>
                 </xs:sequence>
               </xs:complexType>
             </xs:element>

             <xs:element minOccurs="0" name="HopRawOutputData"
                         type="tr:string255">
               <xs:annotation>
                 <xs:documentation>Specifies the raw output data
                 returned by the traceroute measurement for a
                 certain hop in a traceroute measurement path.  It is
                 an implementation-dependent, printable string,
                 expected to be useful for a human interpreting the
                 traceroute results.</xs:documentation>
               </xs:annotation>
             </xs:element>
           </xs:sequence>
         </xs:complexType>
       </xs:element>
     </xs:sequence>
   </xs:complexType>

   <xs:complexType name="_Metadata">
     <xs:annotation>
       <xs:documentation>Specifies the metadata for a traceroute
       operation -- the parameters requested if used in

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       "RequestMetadata" or the actual parameters used if used in
       "MeasurementMetadata".</xs:documentation>
     </xs:annotation>

     <xs:sequence>
       <xs:element name="TestName" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the name of a traceroute
           measurement.  This is not necessarily unique within any
           well-defined scope (e.g., a specific host, initiator of
           the traceroute measurement).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="" name="OSName" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the name of the operating
           system on which the traceroute measurement was launched.
           This element is ignored if used in the
           "RequestMetadata".</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="" name="OSVersion" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the OS version on which the
           traceroute measurement was launched.  This element is
           ignored if used in the
           "RequestMetadata".</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="" name="ToolVersion" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the version of the traceroute
           tool (requested to be used if in the "RequestMetadata"
           element, actually used if in the "MeasurementMetadata"
           element).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="" name="ToolName" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the name of the traceroute
           tool (requested to be used if in the "RequestMetadata"
           element, actually used if in the "MeasurementMetadata"
           element).</xs:documentation>
         </xs:annotation>

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       </xs:element>

       <xs:element name="CtlTargetAddress" type="tr:inetAddress">
         <xs:annotation>
           <xs:documentation>In the "RequestMetadata" element, it
           specifies the host address requested to be used in the
           traceroute measurement.  In the "MeasurementMetadata"
           element, it specifies the host address used in the
           traceroute measurement.  The host address type can be
           determined by examining the "inetAddress" type name and
           the corresponding element value.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="false" name="CtlBypassRouteTable"
                   type="xs:boolean">
         <xs:annotation>
           <xs:documentation>In the "RequestMetadata" element
           specifies if the optional bypassing of the route
           table was enabled or not.  In the "MeasurementMetadata"
           element, specifies if the optional bypassing of the route
           table was enabled or not.  If enabled, the normal routing
           tables will be bypassed and the probes will be sent
           directly to a host on an attached network.  If the host is
           not on a directly attached network, an error is returned.
           This option can be used to perform the traceroute
           measurement to a local host through an interface that has
           no route defined.  This object can be used when the
           setsockopt SOL_SOCKET SO_DONTROUTE option is supported and
           set (see the POSIX standard IEEE.1003-1G.1997).
           </xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="0" name="CtlProbeDataSize">
         <xs:annotation>
           <xs:documentation>Specifies the size of the probes of a
           traceroute measurement in octets (requested if in the
           "RequestMetadata" element, actually used if in the
           "MeasurementMetadata" element).  If UDP datagrams are used
           as probes, then the value contained in this object is
           exact.  If another protocol is used to transmit probes
           (i.e., TCP or ICMP) for which the specified size is not
           appropriate, then the implementation can use whatever
           size (appropriate to the method) is closest to the
           specified size.  The maximum value for this object is
           computed by subtracting the smallest possible IP header
           size of 20 octets (IPv4 header with no options) and the

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           UDP header size of 8 octets from the maximum IP packet
           size.  An IP packet has a maximum size of 65535 octets
           (excluding IPv6 jumbograms).</xs:documentation>
         </xs:annotation>

         <xs:simpleType>
           <xs:restriction base="xs:unsignedShort">
             <xs:maxInclusive value="65507"/>
           </xs:restriction>
         </xs:simpleType>
       </xs:element>

       <xs:element default="3" name="CtlTimeOut">
         <xs:annotation>
           <xs:documentation>Specifies the timeout value, in
           seconds, for each probe of a traceroute measurement
           (requested if in the "RequestMetadata" element, actually
           used if in the "MeasurementMetadata"
           element).</xs:documentation>
         </xs:annotation>

         <xs:simpleType>
           <xs:restriction base="xs:unsignedByte">
             <xs:minInclusive value="1"/>

             <xs:maxInclusive value="60"/>
           </xs:restriction>
         </xs:simpleType>
       </xs:element>

       <xs:element default="3" name="CtlProbesPerHop">
         <xs:annotation>
           <xs:documentation>Specifies the number of probes with the
           same time-to-live (TTL) value that are sent for each host
           (requested if in the "RequestMetadata" element, actually
           used if in the "MeasurementMetadata"
           element).</xs:documentation>
         </xs:annotation>

         <xs:simpleType>
           <xs:restriction base="xs:unsignedByte">
             <xs:minInclusive value="1"/>

             <xs:maxInclusive value="10"/>
           </xs:restriction>
         </xs:simpleType>
       </xs:element>

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       <xs:element default="33434" name="CtlPort">
         <xs:annotation>
           <xs:documentation>Specifies the base port used by the
           traceroute measurement (requested if in the
           "RequestMetadata" element, actually used if in the
           "MeasurementMetadata" element).</xs:documentation>
         </xs:annotation>

         <xs:simpleType>
           <xs:restriction base="xs:unsignedShort">
             <xs:minInclusive value="1"/>
           </xs:restriction>
         </xs:simpleType>
       </xs:element>

       <xs:element default="30" name="CtlMaxTtl" type="tr:u8nonzero">
         <xs:annotation>
           <xs:documentation>Specifies the maximum TTL value for the
           traceroute measurement (requested if in the
           "RequestMetadata" element, actually used if in the
           "MeasurementMetadata" element).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="0" name="CtlDSField"
                   type="xs:unsignedByte">
         <xs:annotation>
           <xs:documentation>Specifies the value that was requested
           to be stored in the Differentiated Services (DS) field in
           the traceroute probe (if in the "RequestMetadata"
           element).  Specifies the value that was stored in the
           Differentiated Services (DS) field in the traceroute
           probe (if in the "MeasurementMetadata" element).  The DS
           field is defined as the Type of Service (TOS) octet in an
           IPv4 header or as the Traffic Class octet in an IPv6
           header (see Section 7 of [RFC2460]).  The value of this
           object must be a decimal integer in the range from 0 to
           255.  This option can be used to determine what effect an
           explicit DS field setting has on a traceroute measurement
           and its probes.  Not all values are legal or meaningful.
           Useful TOS octet values are probably 16 (low delay) and
           8 (high throughput).  Further references can be found in
           [RFC2474] for the definition of the Differentiated
           Services (DS) field and in [RFC1812] Section 5.3.2 for
           Type of Service (TOS).</xs:documentation>
         </xs:annotation>
       </xs:element>

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       <xs:element name="CtlSourceAddress"
                   type="tr:inetAddressWithoutDns">
         <xs:annotation>
           <xs:documentation>Specifies the IP address (which has to
           be given as an IP number, not a hostname) as the source
           address in traceroute probes (requested if in the
           "RequestMetadata" element, actually used if in the
           "MeasurementMetadata" element).  On hosts with more than
           one IP address, this option can be used in the
           "RequestMetadata" element to force the source address to
           be something other than the primary IP address of the
           interface the probe is sent on; the value "unknown" means
           the default address will be used.  The address type can be
           determined by examining the "inetAddress" type name and the
           corresponding element value.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="0" name="CtlIfIndex"
                   type="xs:unsignedInt">
         <xs:annotation>
           <xs:documentation>Specifies the interface index as
           defined in [RFC2863] that is requested to be used in the
           traceroute measurement for sending the traceroute probes
           (if in the "RequestMetadata" element).  A value of 0
           indicates that no specific interface is requested.
           Specifies the interface index actually used (if in the
           "MeasurementMetadata" element).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element minOccurs="0" name="CtlMiscOptions"
                   type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies implementation-dependent
           options (requested if in the "RequestMetadata" element,
           actually used if in the "MeasurementMetadata"
           element).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="5" name="CtlMaxFailures"
                   type="xs:unsignedByte">
         <xs:annotation>
           <xs:documentation>Specifies the maximum number of
           consecutive timeouts allowed before terminating a
           traceroute measurement (requested if in the
           "RequestMetadata" element, actually used if in the

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           "MeasurementMetadata" element).  A value of either 255
           (maximum hop count/possible TTL value) or 0 indicates
           that the function of terminating a remote traceroute
           measurement when a specific number of consecutive
           timeouts are detected was disabled.  This element is
           included to give full compatibility with [RFC4560].  No
           known implementation of traceroute currently supports
           it.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="false" name="CtlDontFragment"
                   type="xs:boolean">
         <xs:annotation>
           <xs:documentation>Specifies if the don't fragment (DF)
           flag in the IP header for a probe was enabled or not (if
           in the "MeasurementMetadata" element).  If in the
           "RequestMetadata", it specifies if the flag was requested
           to be enabled or not.  Setting the DF flag can be used for
           performing a manual PATH MTU test.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element default="1" name="CtlInitialTtl"
                   type="tr:u8nonzero">
         <xs:annotation>
           <xs:documentation>Specifies the initial TTL value for a
           traceroute measurement (requested if in the
           "RequestMetadata" element, actually used if in the
           "MeasurementMetadata" element).  Such TTL setting is
           intended to bypass the initial (often well-known) portion
           of a path.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element maxOccurs="1" minOccurs="0" name="CtlDescr"
                   type="tr:string255">
         <xs:annotation>
           <xs:documentation>Provides a description of the traceroute
           measurement.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element name="CtlType" type="tr:_CtlType">
         <xs:annotation>
           <xs:documentation>Specifies the implementation method
           used for the traceroute measurement (requested if in the
           "RequestMetadata" element, actually used if in the

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           "MeasurementMetadata" element).  It specifies if the
           traceroute is using TCP, UDP, ICMP, or other types of
           probes.  It is possible to specify other types of probes
           by using an element specified in another schema with a
           different namespace.</xs:documentation>
         </xs:annotation>
       </xs:element>
     </xs:sequence>
   </xs:complexType>

   <xs:complexType name="_Measurement">
     <xs:annotation>
       <xs:documentation>Contains the actual traceroute measurement
       results.</xs:documentation>
     </xs:annotation>

     <xs:sequence>
       <xs:element name="TestName" type="tr:string255">
         <xs:annotation>
           <xs:documentation>Specifies the name of a traceroute
           measurement.  This is not necessarily unique within any
           well-defined scope (e.g., a specific host, initiator of
           the traceroute measurement).</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element name="ResultsStartDateAndTime" type="xs:dateTime">
         <xs:annotation>
           <xs:documentation>Specifies the date and start time of
           the traceroute measurement.  This is the time when the
           first probe was seen at the sending
           interface.</xs:documentation>
         </xs:annotation>
       </xs:element>

       <xs:element name="ResultsIpTgtAddr"
                   type="tr:inetAddressWithoutDns">
         <xs:annotation>
           <xs:documentation>Specifies the IP address associated
           with a "CtlTargetAddress" value when the destination
           address is specified as a DNS name.  The value of this
           object should be "unknown" if a DNS name is not specified
           or if a specified DNS name fails to resolve.  The
           address type can be determined by examining the "inetAddress"
           type name and the corresponding element
           value.</xs:documentation>
         </xs:annotation>
       </xs:element>

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       <xs:element name="ProbeResults" type="tr:_ProbeResults"/>

       <xs:element name="ResultsEndDateAndTime" type="xs:dateTime">
         <xs:annotation>
           <xs:documentation>Specifies the date and end time of the
           traceroute measurement.  It is either the time when the
           response to the last probe of the traceroute measurement
           was received or the time when the last probe of the
           traceroute measurement was sent plus the relative timeout
           (in case of a missing response).</xs:documentation>
         </xs:annotation>
       </xs:element>
     </xs:sequence>
   </xs:complexType>

   <xs:element name="traceRoute">
     <xs:complexType>
       <xs:sequence>
         <xs:element minOccurs="0" name="RequestMetadata"
                     type="tr:_Metadata"/>

         <xs:element maxOccurs="2147483647" minOccurs="0"
                     name="Measurement">
           <xs:complexType>
             <xs:sequence>
               <xs:element minOccurs="0" name="MeasurementMetadata"
                           type="tr:_Metadata"/>

               <xs:element maxOccurs="2147483647" minOccurs="0"
                           name="MeasurementResult"
                           type="tr:_Measurement"/>
             </xs:sequence>
           </xs:complexType>
         </xs:element>
       </xs:sequence>
     </xs:complexType>
   </xs:element>
 </xs:schema>

8.  Security Considerations

   Security considerations discussed in this section are grouped into
   considerations related to conducting traceroute measurements and
   considerations related to storing and transmitting traceroute
   measurement information.

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   This memo does not specify an implementation of a traceroute tool.
   Neither does it specify a certain procedure for storing traceroute
   measurement information.  Still, it is considered desirable to
   discuss related security issues below.

8.1.  Conducting Traceroute Measurements

   Conducting Internet measurements can raise both security and privacy
   concerns.  Traceroute measurements, in which traffic is injected into
   the network, can be abused for denial-of-service attacks disguised as
   legitimate measurement activity.

   Measurement parameters MUST be carefully selected so that the
   measurements inject trivial amounts of additional traffic into the
   networks they measure.  If they inject "too much" traffic, they can
   skew the results of the measurement, and in extreme cases cause
   congestion and denial of service.

   The measurements themselves could be harmed by routers giving
   measurement traffic a different priority than "normal" traffic, or by
   an attacker injecting artificial measurement traffic.  If routers can
   recognize measurement traffic and treat it separately, the
   measurements will not reflect actual user traffic.  If an attacker
   injects artificial traffic that is accepted as legitimate, the loss
   rate will be artificially lowered.  Therefore, the measurement
   methodologies SHOULD include appropriate techniques to reduce the
   probability that measurement traffic can be distinguished from
   "normal" traffic.

   Authentication techniques, such as digital signatures, may be used
   where appropriate to guard against injected traffic attacks.

8.2.  Securing Traceroute Measurement Information

   Traceroute measurement information is not considered highly
   sensitive.  Still, it may contain sensitive information on network
   paths, routing states, used IP addresses, and roundtrip times that
   operators of networks may want to protect for business or security
   reasons.

   It is thus important to control access to information acquired by
   conducting traceroute measurements, particularly when transmitting it
   over a networks but also when storing it.  It is RECOMMENDED that a
   transmission of traceroute measurement information over a network
   uses appropriate protection mechanisms for preserving privacy,
   integrity, and authenticity.  It is further RECOMMENDED that secure
   authentication and authorization are used for protecting stored
   traceroute measurement information.

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9.  IANA Considerations

   This document uses URNs to describe an XML namespace and an XML
   schema for traceroute measurement information storing and
   transmission, conforming to a registry mechanism described in
   [RFC3688].  Two URI assignments have been made.

   1.  Registration for the IPPM traceroute measurements namespace

       *  URI: urn:ietf:params:xml:ns:traceroute-1.0

       *  Registrant Contact: IESG

       *  XML: None.  Namespace URIs do not represent an XML.

   2.  Registration for the IPPM traceroute measurements schema

       *  URI: urn:ietf:params:xml:schema:traceroute-1.0

       *  Registrant Contact: IESG

       *  XML: See Section 7 of this document.

10.  References

10.1.  Normative References

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

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

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB", RFC 2863, June 2000.

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

   [RFC3339]  Klyne, G., Ed. and C. Newman, "Date and Time on the
              Internet: Timestamps", RFC 3339, July 2002.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, November 2003.

Top      Up      ToC       Page 41 
   [RFC4001]  Daniele, M., Haberman, B., Routhier, S., and J.
              Schoenwaelder, "Textual Conventions for Internet Network
              Addresses", RFC 4001, February 2005.

   [RFC4560]  Quittek, J. and K. White, "Definitions of Managed Objects
              for Remote Ping, Traceroute, and Lookup Operations",
              RFC 4560, June 2006.

   [RFC5198]  Klensin, J. and M. Padlipsky, "Unicode Format for Network
              Interchange", RFC 5198, March 2008.

10.2.  Informative References

   [IEEE.1003-1G.1997]
              Institute of Electrical and Electronics Engineers,
              "Protocol Independent Interfaces", IEEE Standard 1003.1G,
              March 1997.

   [IPFIX]    Sadasivan, G., "Architecture for IP Flow Information
              Export", Work in Progress, September 2006.

   [RFC1812]  Baker, F., "Requirements for IP Version 4 Routers",
              RFC 1812, June 1995.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474,
              December 1998.

   [RFC2578]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Structure of Management Information
              Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.

   [RFC2579]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Textual Conventions for SMIv2",
              STD 58, RFC 2579, April 1999.

   [RFC2580]  McCloghrie, K., Perkins, D., and J. Schoenwaelder,
              "Conformance Statements for SMIv2", STD 58, RFC 2580,
              April 1999.

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

   [RFC5101]  Claise, B., "Specification of the IP Flow Information
              Export (IPFIX) Protocol for the Exchange of IP Traffic
              Flow Information", RFC 5101, January 2008.

Top      Up      ToC       Page 42 
   [RFC5102]  Quittek, J., Bryant, S., Claise, B., Aitken, P., and J.
              Meyer, "Information Model for IP Flow Information Export",
              RFC 5102, January 2008.

   [W3C.REC-xml-20060816]
              Bray, T., Paoli, J., Maler, E., Sperberg-McQueen, C., and
              F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fourth
              Edition)", World Wide Web Consortium FirstEdition REC-xml-
              20060816, August 2006,
              <http://www.w3.org/TR/2006/REC-xml-20060816>.

   [W3C.REC-xmlschema-2-20041028]
              Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes
              Second Edition", World Wide Web Consortium
              Recommendation REC-xmlschema-2-20041028, October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

Top      Up      ToC       Page 43 
Appendix A.  Traceroute Default Configuration Parameters

   This section lists traceroute measurement configuration parameters as
   well as their defaults on various platforms and illustrates how
   widely they may vary.  This document considers four major traceroute
   tool implementations and compares them based on configurable
   parameters and default values.  The LINUX (SUSE 9.1), BSD (FreeBSD
   7.0), and UNIX (SunOS 5.9) implementations are based on UDP
   datagrams, while the WINDOWS (XP SP2) one uses ICMP Echoes.  The
   comparison is summarized in the following table, where an N/A in the
   option column means that such parameter is not configurable for the
   specific implementation.  A comprehensive comparison of available
   implementations is outside the scope of this document; however, by
   sampling a few different implementations, it can be observed that
   they can differ quite significantly in terms of configurable
   parameters and also default values.  Note that in the following table
   only those options that are available in at least two of the
   considered implementations are reported.

             +---------------------------------------------------------+
             |  OS    |Option|           Description         | Default |
             +--------+------+-------------------------------+---------+
             | LINUX  | -m   |Specify the maximum TTL used   |   30    |
             |--------+------|in traceroute probes.          |---------|
             | FreeBSD| -m   |                               |  OS var |
             |--------+------|                               |---------|
             | UNIX   | -m   |                               |   30    |
             |--------+------|                               |---------|
             | WINDOWS| -h   |                               |   30    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -n   |Display hop addresses          |    -    |
             |--------+------|numerically rather than        |---------|
             | FreeBSD| -n   |symbolically.                  |    -    |
             |--------+------|                               |---------|
             | UNIX   | -n   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| -d   |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -w   |Set the time to wait for a     |  3 sec  |
             |--------+------|response to a probe.           |---------|
             | FreeBSD| -w   |                               |  5 sec  |
             |--------+------|                               |---------|
             | UNIX   | -w   |                               |  5 sec  |
             |--------+------|                               |---------|
             | WINDOWS| -w   |                               |  4 sec  |

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             +--------+------+-------------------------------+---------+
             | LINUX  | N/A  |Specify a loose source route   |    -    |
             |--------+------|gateway (to direct the         |---------|
             | FreeBSD| -g   |traceroute probes through      |    -    |
             |--------+------|routers not necessarily in     |---------|
             | UNIX   | -g   | the path).                    |    -    |
             |--------+------|                               |---------|
             | WINDOWS| -g   |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -p   |Set the base UDP port number   |  33434  |
             |------- +------|used in traceroute probes      |---------|
             | FreeBSD| -p   |(UDP port = base + nhops - 1). |  33434  |
             |--------+------|                               |---------|
             | UNIX   | -p   |                               |  33434  |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -q   |Set the number of probes per   |    3    |
             |--------+------|TTL.                           |---------|
             | FreeBSD| -q   |                               |    3    |
             |--------+------|                               |---------|
             | UNIX   | -q   |                               |    3    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    3    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -S   |Set the IP source address in   |IP       |
             |--------+------|outgoing probes to the         |address  |
             | FreeBSD| -s   |specified value.               |of the   |
             |--------+------|                               |out      |
             | UNIX   | -s   |                               |interface|
             |--------+------|                               |         |
             | WINDOWS| N/A  |                               |         |
             +--------+------+-------------------------------+---------+
             | LINUX  | -t   |Set the Type of Service (TOS)  |    0    |
             |--------+------|in the probes to the specified |---------|
             | FreeBSD| -t   |value.                         |    0    |
             |--------+------|                               |---------|
             | UNIX   | -t   |                               |    0    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    0    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -v   |Verbose output: received ICMP  |    -    |
             |--------+------|packets other than             |---------|
             | FreeBSD| -v   |TIME_EXCEEDED and              |    -    |
             |--------+------|UNREACHABLE are listed.        |---------|
             | UNIX   | -v   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |

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             +--------+------+-------------------------------+---------+
             | LINUX  | N/A  |Set  the time (in msec) to     |    -    |
             |--------+------|pause between probes.          |---------|
             | FreeBSD| -z   |                               |    0    |
             |--------+------|                               |---------|
             | UNIX   | -P   |                               |    0    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -r   |Bypass the normal routing      |    -    |
             |--------+------|tables and send directly to a  |---------|
             | FreeBSD| -r   |host on attached network.      |    -    |
             |--------+------|                               |---------|
             | UNIX   | -r   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -f   |Set the initial TTL for the    |    1    |
             |--------+------|first probe.                   |---------|
             | FreeBSD| -f   |                               |    1    |
             |--------+------|                               |---------|
             | UNIX   | -f   |                               |    1    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    1    |
             +--------+------+-------------------------------+---------+
             | LINUX  | -F   |Set the "don't fragment" bit.  |    -    |
             |--------+------|                               |---------|
             | FreeBSD| -F   |                               |    -    |
             |--------+------|                               |---------|
             | UNIX   | -F   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | N/A  |Enable socket level debugging. |    -    |
             |--------+------|                               |---------|
             | FreeBSD| -d   |                               |    -    |
             |--------+------|                               |---------|
             | UNIX   | -d   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | N/A  |Use ICMP Echoes instead of UDP |    -    |
             |--------+------|datagrams.                     |---------|
             | FreeBSD| -I   |                               |    -    |
             |--------+------|                               |---------|
             | UNIX   | -I   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |

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             +--------+------+-------------------------------+---------+
             | LINUX  | -I   |Specify a network interface to |    -    |
             |--------+------|obtain the IP address for      |---------|
             | FreeBSD| -i   |outgoing IP packets            |    -    |
             |--------+------|(alternative to option -s).    |---------|
             | UNIX   | -i   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  | N/A  |Toggle checksum.               |    -    |
             |--------+------|                               |---------|
             | FreeBSD| -x   |                               |    -    |
             |--------+------|                               |---------|
             | UNIX   | -x   |                               |    -    |
             |--------+------|                               |---------|
             | WINDOWS| N/A  |                               |    -    |
             +--------+------+-------------------------------+---------+
             | LINUX  |  -   |As optional last parameter,    |Depends  |
             |--------+------|LINUX, FreeBSD, and UNIX       |on       |
             | FreeBSD|  -   |implementations allow          |implement|
             |--------+------|specifying the probe datagram  |ation.   |
             | UNIX   |  -   |length for outgoing probes.    |         |
             |--------+------|                               |         |
             | WINDOWS| N/A  |                               |         |
             +--------+------+-------------------------------+---------+

A.1.  Alternative Traceroute Implementations

   As stated above, the widespread use of firewalls might prevent UDP-
   or ICMP-based traceroutes to completely trace the path to a
   destination since traceroute probes might end up being filtered.  In
   some cases, such limitation might be overcome by sending instead TCP
   packets to specific ports that hosts located behind the firewall are
   listening for connections on.  TCP-based implementations use TCP,
   SYN, or FIN probes and listen for TIME_EXCEEDED messages, TCP RESET,
   and other messages from firewalls and gateways on the path.  On the
   other hand, some firewalls filter out TCP SYN packets to prevent
   denial-of-service attacks; therefore, the actual advantage of using
   TCP instead of UDP traceroute depends mainly on firewall
   configurations, which are not known in advance.  A detailed analysis
   of TCP-based traceroute tools and measurements is outside the scope
   of this document; regardless, for completeness reasons, the
   information model also supports the storing of TCP-based traceroute
   measurements.


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