Initial Performance Metric Registry Entries

Note: Efforts to synchronize structure and terminology with will likely be incomplete until both drafts are stable. This memo proposes an initial set of entries for the Performance Metric Registry. It uses terms and definitions from the IPPM literature, primarily . Proponents of Passive Performance Metrics are encouraged to develop a similar document. Although there are several standard templates for organizing specifications of performance metrics (see for an example of the traditional IPPM template, based to large extent on the Benchmarking Methodology Working Group's traditional template in , and see for a similar template), none of these templates were intended to become the basis for the columns of an IETF-wide registry of metrics. While examinating aspects of metric specifications which need to be registered, it became clear that none of the existing metric templates fully satisfies the particular needs of a registry. Therefore, defines the overall format for a Performance Metric Registry. Section 5 of also gives guidelines for those requesting registration of a Metric, that is the creation of entry(s) in the Performance Metric Registry: "In essence, there needs to be evidence that a candidate Registered Performance Metric has significant industry interest, or has seen deployment, and there is agreement that the candidate Registered Performance Metric serves its intended purpose." The process in also requires that new entries are administered by IANA through Expert Review, which will ensure that the metrics are tightly defined.

This document defines the initial set of Performance Metrics Registry entries, for which IETF approval (following development in the IP Performance Metrics (IPPM) Working Group) will satisfy the requirement for Expert Review. Note that all are Active Performance Metrics, which are based on RFCs prepared in the IPPM working group of the IETF, according to their framework and its updates.

This section provides the categories and columns of the registry, for easy reference. An entry (row) therefore gives a complete description of a Registered Metric.

This section gives an initial registry entry for the UDP Round-trip Latency. Note: Each Registry entry only produces a "raw" output or a statistical summary. To describe both "raw" and one or more statistics efficiently, the Identifier, Name, and Output Categories can be split and this section can become two or more closely-related metrics. See Section 7 for an example specifying multiple Registry entries with many common columns.

This category includes multiple indexes to the registry entry: the element ID and metric name.

<insert name according to metric naming convention> RTDelay_Active_UDP_RFCXXXXsecY_Seconds_95%tile

URN: Prefix urn:ietf:params:performance:metric:<name> URL: http://<TBD by IANA>/<name>

This metric assesses the delay of a stream of packets exchanged between two hosts (which are the two measurement points), and the Output is the Round-trip delay for all successfully exchanged packets expressed as the 95th percentile of their conditional delay distribution.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<Full bibliographic reference to an immutable doc.> Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip Delay Metric for IPPM", RFC 2681, September 1999. <specific section reference and additional clarifications, if needed> Section 2.4 of provides the reference definition of the singleton (single value) Round-trip delay metric. Section 3.4 of provides the reference definition expanded to cover a multi-singleton sample. Note that terms such as singleton and sample are defined in Section 11 of . Note that although the definition of "Round-trip-Delay between Src and Dst" is directionally ambiguous in the text, this metric tightens the definition further to recognize that the host in the "Src" role will send the first packet to "Dst", and ultimately receive the corresponding return packet from "Dst" (when neither are lost). Finally, note that the variable "dT" is used in to refer to the value of Round-trip delay in metric definitions and methods. The variable "dT" has been re-used in other IPPM literature to refer to different quantities, and cannot be used as a global variable name.

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> Type-P as defined in Section 13 of : IPv4 header values: DSCP: set to 0 TTL: set to 255 Protocol: Set to 17 (UDP) IPv6 header values: DSCP: set to 0 Hop Count: set to 255 Protocol: Set to 17 (UDP) UDP header values: Checksum: the checksum MUST be calculated UDP Payload total of 9 bytes Other measurement parameters: Tmax: a loss threshold waiting time 3.0, expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) and with resolution of 0.0001 seconds (0.1 ms), with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of .

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

<for metric, insert relevant section references and supplemental info> The methodology for this metric is defined as Type-P-Round-trip-Delay-Poisson-Stream in section 2.6 of RFC 2681 and section 3.6 of RFC 2681 using the Type-P and Tmax defined under Fixed Parameters. The reference method distinguishes between long-delayed packets and lost packets by implementing a maximum waiting time for packet arrival. Tmax is the waiting time used as the threshold to declare a packet lost. Lost packets SHALL be designated as having undefined delay. The calculations on the delay (RTT) SHALL be performed on the conditional distribution, conditioned on successful packet arrival within Tmax. Also, when all packet delays are stored, the process which calculates the RTT value MAY enforce the Tmax threshold on stored values before calculations. See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. The reference method requires some way to distinguish between different packets in a stream to establish correspondence between sending times and receiving times for each successfully-arriving packet. Sequence numbers or other send-order identification MUST be retained at the Src or included with each packet to dis-ambiguate packet reordering if it occurs. If a standard measurement protocol is employed, then the measurement process will determine the sequence numbers or timestamps applied to test packets after the Fixed and Runtime parameters are passed to that process. The chosen measurement protocol will dictate the format of sequence numbers and time-stamps, if they are conveyed in the packet payload. Refer to Section 4.4 of for expanded discussion of the instruction to "send a Type-P packet back to the Src as quickly as possible" in Section 2.6 of RFC 2681. Section 8 of presents additional requirements which MUST be included in the method of measurement for this metric.

This section gives the details of the packet traffic which is the basis for measurement. In IPPM metrics, this is called the Stream, and can easily be described by providing the list of stream parameters. <section/specification references, and description of any new generation parameters, if needed> Section 11.1.3 of provides three methods to generate Poisson sampling intervals. the reciprocal of lambda is the average packet spacing, thus the Run-time Parameter is Reciprocal_lambda = 1/lambda, in seconds. >>> Check with Sam, most likely it is this... Method 3 SHALL be used, where given a start time (Run-time Parameter), the subsequent send times are all computed prior to measurement by computing the pseudo-random distribution of inter-packet send times, (truncating the distribution as specified in the Run-time Parameter, Trunc), and the Src sends each packet at the computed times. Note that Trunc is the upper limit on inter-packet times in the Poisson distribution. A random value greater than Trunc is set equal to Trunc instead.

The measured results based on a filtered version of the packets observed, and this section provides the filter details (when present). <section reference>. NA

<insert time distribution details, or how this is diff from the filter> NA

Run-time Parameters are input factors that must be determined, configured into the measurement system, and reported with the results for the context to be complete. <list of run-time parameters, and their data formats> the IP address of the host in the Src Role (format ipv4-address-no-zone value for IPv4, or ipv6-address-no-zone value for IPv6, see Section 4 of ) the IP address of the host in the Dst Role (format ipv4-address-no-zone value for IPv4, or ipv6-address-no-zone value for IPv6, see section 4 of ) a time, the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . When T0 is "all-zeros", a start time is unspecified and Tf is to be interpreted as the Duration of the measurement interval. The start time is controlled through other means. a time, the end of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . When T0 is "all-zeros", a end time date is ignored and Tf is interpreted as the Duration of the measurement interval. average packet interval for Poisson Streams expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) with resolution of 0.0001 seconds (0.1 ms), and with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of . Upper limit on Poisson distribution expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) with resolution of 0.0001 seconds (0.1 ms), and with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of (values above this limit will be clipped and set to the limit value). (if fixed, Trunc = 30.0000 seconds.) >>> should Poisson run-time params be fixed instead? probably yes if modeling a specific version of MBA tests.

<lists the names of the different roles from the measurement method> launches each packet and waits for return transmissions from Dst. waits for each packet from Src and sends a return packet to Src.

This category specifies all details of the Output of measurements using the metric.

<insert name of the output type, raw or a selected summary statistic> Percentile -- for the conditional distribution of all packets with a valid value of Round-trip delay (undefined delays are excluded), a single value corresponding to the 95th percentile, as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. The percentile = 95, meaning that the reported delay, "Percentile95", is the smallest value of Round-trip delay for which the Empirical Distribution Function (EDF), F(Percentile95) >= 95% of the singleton Round-trip delay values in the conditional distribution. See section 11.3 of for the definition of the percentile statistic using the EDF.

<describe the data format for each type of result> For all outputs --- the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . Raw -- REMOVED IN VERSION 01 For Act_IP_UDP_Round-trip_Delay_Poisson_95th-percentile: The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of ) with resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of RFC

<pointer to section/spec where output type/format is defined> See the Data Format column for references.

<insert units for the measured results, and the reference specification>. The 95th Percentile of Round-trip Delay is expressed in seconds.

name or RFC, etc.

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Additional (Informational) details for this entry

This section gives an initial registry entry for a Packet Delay Variation metric. Note: If each Registry entry should only produce a "raw" output or a statistical summary, then the "Output" Category can be split and this section can become two closely-related metrics.

This category includes multiple indexes to the registry entries, the element ID and metric name. <skipping some Summary columns for now>

<insert name according to metric naming convention> Act_IP-UDP-One-way-pdv-95th-percentile-Poisson OwPDV_Active_UDP_Poisson_RFCXXXXsecY_Seconds_95%tile

URI: Prefix urn:ietf:params:performance:metric:<name> URL: http://<TBD by IANA>/<name>

An assessment of packet delay variation with respect to the minimum delay observed on the stream, and the Output is expressed as the 95th percentile of the packet delay variation distribution.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<Full bibliographic reference to an immutable doc.> Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, May 1998. Demichelis, C. and P. Chimento, "IP Packet Delay Variation Metric for IP Performance Metrics (IPPM)", RFC 3393, November 2002. Morton, A. and B. Claise, "Packet Delay Variation Applicability Statement", RFC 5481, March 2009. Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, June 2010. <specific section reference and additional clarifications, if needed> See sections 2.4 and 3.4 of . Singleton delay differences measured are referred to by the variable name "ddT" (applicable to all forms of delay variation). However, this metric entry specifies the PDV form defined in section 4.2 of , where the singleton PDV for packet i is referred to by the variable name "PDV(i)".

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> IPv4 header values: DSCP: set to 0 TTL: set to 255 Protocol: Set to 17 (UDP) IPv6 header values: DSCP: set to 0 Hop Count: set to 255 Protocol: Set to 17 (UDP) UDP header values: Checksum: the checksum MUST be calculated UDP Payload total of 200 bytes Other measurement parameters: a loss threshold waiting time with value 3.0, expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) and with resolution of 0.0001 seconds (0.1 ms), with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of . a selection function unambiguously defining the packets from the stream selected for the metric. See section 4.2 of for the PDV form.

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

<for metric, insert relevant section references and supplemental info> See section 2.6 and 3.6 of for general singleton element calculations. This metric entry requires implementation of the PDV form defined in section 4.2 of . Also see measurement considerations in section 8 of . The reference method distinguishes between long-delayed packets and lost packets by implementing a maximum waiting time for packet arrival. Tmax is the waiting time used as the threshold to declare a packet lost. Lost packets SHALL be designated as having undefined delay. The calculations on the one-way delay SHALL be performed on the conditional distribution, conditioned on successful packet arrival within Tmax. Also, when all packet delays are stored, the process which calculates the one-way delay value MAY enforce the Tmax threshold on stored values before calculations. See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. The reference method requires some way to distinguish between different packets in a stream to establish correspondence between sending times and receiving times for each successfully-arriving packet. Sequence numbers or other send-order identification MUST be retained at the Src or included with each packet to dis-ambiguate packet reordering if it occurs. If a standard measurement protocol is employed, then the measurement process will determine the sequence numbers or timestamps applied to test packets after the Fixed and Runtime parameters are passed to that process. The chosen measurement protocol will dictate the format of sequence numbers and time-stamps, if they are conveyed in the packet payload.

<list of generation parameters and section/spec references if needed> Section 11.1.3 of provides three methods to generate Poisson sampling intervals. the reciprocal of lambda is the average packet spacing, thus the Run-time Parameter is Reciprocal_lambda = 1/lambda, in seconds. >>> Check with Sam, most likely it is this... Method 3 SHALL be used, where given a start time (Run-time Parameter), the subsequent send times are all computed prior to measurement by computing the pseudo-random distribution of inter-packet send times, (truncating the distribution as specified in the Run-time Parameter, Trunc), and the Src sends each packet at the computed times. Note that Trunc is the upper limit on inter-packet times in the Poisson distribution. A random value greater than Trunc is set equal to Trunc instead. lambda, a rate in reciprocal seconds (for Poisson Streams). lambda = 1 packet per second Upper limit on Poisson distribution (values above this limit will be clipped and set to the limit value). Upper limit = 30 seconds.

<insert the measured results based on a filtered version of the packets observed, and this section provides the filter details (when present), and section reference>. NA

<insert time distribution details, or how this is diff from the filter> NA

<list of run-time parameters, and their data formats> the IP address of the host in the Src Role (format ipv4-address-no-zone value for IPv4, or ipv6-address-no-zone value for IPv6, see Section 4 of ) the IP address of the host in the Dst Role (format ipv4-address-no-zone value for IPv4, or ipv6-address-no-zone value for IPv6, see section 4 of ) a time, the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . When T0 is "all-zeros", a start time is unspecified and Tf is to be interpreted as the Duration of the measurement interval. The start time is controlled through other means. a time, the end of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . When T0 is "all-zeros", a end time date is ignored and Tf is interpreted as the Duration of the measurement interval. average packet interval for Poisson Streams expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) with resolution of 0.0001 seconds (0.1 ms), and with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of . Upper limit on Poisson distribution expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 5 (see section 9.3 of ) with resolution of 0.0001 seconds (0.1 ms), and with lossless conversion to/from the 32-bit NTP timestamp as per section 6 of (values above this limit will be clipped and set to the limit value). (if fixed, Trunc = 30.0000 seconds.) >>> should Poisson run-time params be fixed instead? probably yes if modeling a specific version of MBA tests.

<lists the names of the different roles from the measurement method> launches each packet to Dst. waits for each packet from Src.

This category specifies all details of the Output of measurements using the metric.

<insert name of the output type, raw or a selected summary statistic> Percentile -- for the conditional distribution of all packets with a valid value of one-way delay (undefined delays are excluded), a single value corresponding to the 95th percentile, as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. The percentile = 95, meaning that the reported delay, "Percentile95", is the smallest value of one-way PDV for which the Empirical Distribution Function (EDF), F(Percentile95) >= 95% of the singleton one-way PDV values in the conditional distribution. See section 11.3 of for the definition of the percentile statistic using the EDF.

<describe the data format for each type of result> the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . the start of a measurement interval, (format "date-and-time" as specified in Section 5.6 of , see also Section 3 of ). The UTC Time Zone is required by Section 6.1 of . The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of ) with resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of RFC

<pointer to section/spec where output type/format is defined> See the Data Format column for references.

<insert units for the measured results, and the reference specification>. The 95th Percentile of one-way PDV is expressed in seconds.

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<Additional (Informational) details for this entry> Lost packets represent a challenge for delay variation metrics. See section 4.1 of and the delay variation applicability statement for extensive analysis and comparison of PDV and an alternate metric, IPDV.

This section gives an initial registry entry for DNS Response Latency. RFC 2681 defines a Round-trip delay metric. We build on that metric by specifying several of the input parameters to precisely define a metric for measuring DNS latency.

This category includes multiple indexes to the registry entries, the element ID and metric name. <skipping some admin columns for now>

<insert name according to metric naming convention> RTDNS_Active_UDP_DNS_Poisson_RFCXXXXsecY_Seconds_95%tile

URI: Prefix urn:ietf:params:performance:metric URL:

This metric assesses the response time, the interval from the query transmission to the response.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<Full bibliographic reference to an immutable doc.> Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. (and updates) Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip Delay Metric for IPPM", RFC 2681, September 1999. <specific section reference and additional clarifications, if needed> Section 2.4 of provides the reference definition of the singleton (single value) Round-trip delay metric. Section 3.4 of provides the reference definition expanded to cover a multi-value sample. Note that terms such as singleton and sample are defined in Section 11 of . For DNS Response Latency, the entities in must be mapped to . The Local Host with its User Program and Resolver take the role of "Src", and the Foreign Name Server takes the role of "Dst". Note that although the definition of "Round-trip-Delay between Src and Dst at T" is directionally ambiguous in the text, this metric tightens the definition further to recognize that the host in the "Src" role will send the first packet to "Dst", and ultimately receive the corresponding return packet from "Dst" (when neither are lost).

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> Type-P: IPv4 header values: DSCP: set to 0 TTL set to 255 Protocol: Set to 17 (UDP) UDP header values: Source port: 53 Destination port: 53 Checksum: the checksum must be calculated Payload: The payload contains a DNS message as defined in RFC 1035 with the following values: The DNS header section contains: QR: set to 0 (Query) OPCODE: set to 0 (standard query) AA: not set TC: not set RD: set to one (recursion desired) RA: not set RCODE: not set QDCOUNT: set to one (only one entry) ANCOUNT: not set NSCOUNT: not set ARCOUNT: not set The Question section contains: QNAME: the FQDN provided as input for the test QTYPE: the query type provided as input for the test QCLASS: set to IN The other sections do not contain any Resource Records. Observation: reply packets will contain a DNS response and may contain RRs. Timeout: Tmax = 5 seconds (to help disambiguate queries)

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

This section gives the details of the packet traffic which is the basis for measurement. In IPPM metrics, this is called the Stream, and can easily be dscribed by providing the list of stream parameters. <list of generation parameters and section/spec references if needed> Section 11.1.3 of RFC 2681 provides three methods to generate Poisson sampling intervals. the reciprocal of lambda is the average packet rate, thus the Run-time Parameter is 1/lambda. >>> Check with Sam, most likely it is this... Method 3 is used, where given a start time (Run-time Parameter), the subsequent send times are all computed prior to measurement by computing the pseudo-random distribution of inter-packet send times, (truncating the distribution as specified in the Run-time Parameters), and the Src sends each packet at the computed times.

The measured results based on a filtered version of the packets observed, and this section provides the filter details (when present). <section reference>. NA

<insert time distribution details, or how this is diff from the filter> NA

Run-time Parameters are input factors that must be determined, configured into the measurement system, and reported with the results for the context to be complete. <list of run-time parameters, and their data formats> Src, the IP address of a host (32-bit value for IPv4, 128-bit value for IPv6) Dst, the IP address of a host (32-bit value for IPv4, 128-bit value for IPv6) T0, a time (start of measurement interval, 128-bit NTP Date Format, see section 6 of ). When T0 is "all-zeros", a start time is unspecified and Tf is to be interpreted as the Duration of the measurement interval. Tf, a time (end of measurement interval, 128-bit NTP Date Format, see section 6 of ), interpreted as the Duration of the measurement interval. 1/lambda, average packet rate (for Poisson Streams). (1/lambda = 0.1 packet per second, if fixed) Upper limit on Poisson distribution (values above this limit will be clipped and set to the limit value). (if fixed, Upper limit = 300 seconds.) ID, the 16-bit identifier assigned by the program that generates the query, and which must vary in successive queries, see Section 4.1.1 of . This identifier is copied into the corresponding reply and can be used by the requester to match-up replies to outstanding queries. The format for 1/lambda and Upper limit of Poisson Dist. are the short format in (32 bits) and is as follows: the first 16 bits represent the integer number of seconds; the next 16 bits represent the fractional part of a second. >>> should Poisson run-time params be fixed instead? probably yes if modeling a specific version of MBA tests.

<lists the names of the different roles from the measurement method> Src - launches each packet and waits for return transmissions from Dst. Dst - waits for each packet from Src and sends a return packet to Src.

This category specifies all details of the Output of measurements using the metric.

<insert name of the output type, raw or a selected summary statistic> For all output types: T0, a time (start of measurement interval, 128-bit NTP Date Format, see section 6 of ) Tf, a time (end of measurement interval, 128-bit NTP Date Format, see section 6 of ) Raw -- for each packet sent, pairs of values. >>> and the status of the response, only assigning values to successful query-response pairs. Percentile -- for the conditional distribution of all packets with a valid value of Round-trip delay (undefined delays are excluded), a single value corresponding to the 95th percentile.

<describe the data format for each type of result> Raw -- for each packet sent, pairs of values as follows: T, the time when the packet was sent from Src, 128-bit NTP Date Format, see section 6 of ) dT, a value of Round-trip delay, format is *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second. dT is undefined when the packet is not received at Src in waiting time Tmxax seconds (need undefined code for no-response or un-successful response) Percentile -- for the conditional distribution of all packets with a valid value of Round-trip delay (undefined delays are excluded), a single value as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. See section 4.3 of for details on the percentile statistic (where Round-trip delay should be substituted for "ipdv"). The percentile = 95. Data format is a 32-bit signed floating point value, *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second.

<pointer to section/spec where output type/format is defined> See the Data Format column for references.

<insert units for the measured results, and the reference specification>. Round-trip Delay, dT, is expressed in seconds. The 95th Percentile of Round-trip Delay is expressed in seconds.

name or RFC, etc.

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Additional (Informational) details for this entry

This section gives an initial registry entry for the UDP Poisson One-way Delay. Note: Each Registry "Name" below specifies a single registry entry, whose output format varies according to a component of the name that specifies one form of statistical summary. IANA is asked to assign a different numeric identifiers to each Name. All column entries beside the Summary and Output categories are the same, thus this section proposes five closely-related registry entries. As a result, IANA is also asked to assign corresponding URIs and URLs.

This category includes multiple indexes to the registry entries, the element ID and metric name.

<insert name according to metric naming convention> Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_<statistic> OwDelay_Active_IP_UDP_Poisson_UDP_Payload_250_RFCXXXXsecY_Seconds_<statistic> Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_Percentile95 Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_Mean Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_Min Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_Max Act_IP_UDP_Poisson_UDP-Payload-250_One-way_Delay_Std_Dev

URI: Prefix urn:ietf:params:performance:metric...<name> URL: http:\\www.iana.org\ ... <name>

This metric assesses the delay of a stream of packets exchanged between two hosts (or measurement points), and reports the <statistic> One-way delay for all successfully exchanged packets based on their conditional delay distribution.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<Full bibliographic reference to an immutable doc.> Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way Delay Metric for IPPM", RFC 2679, September 1999. Morton, A., and Stephan, E., "Spatial Composition of Metrics", RFC 6049, January 2011. <specific section reference and additional clarifications, if needed> Section 3.4 of provides the reference definition of the singleton (single value) One-way delay metric. Section 4.4 of provides the reference definition expanded to cover a multi-value sample. Note that terms such as singleton and sample are defined in Section 11 of . Only successful packet transfers with finite delay are included in the sample, as prescribed in section 4.1.2 of . NOTE: RFC2679 will be replaced by 2679-bis on approval, see draft-ietf-ippm-2679-bis-01.

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> Type-P: IPv4 header values: DSCP: set to 0 TTL set to 255 Protocol: Set to 17 (UDP) UDP header values: Checksum: the checksum must be calculated UDP Payload: TWAMP Test Packet Formats, Section 4.1.2 of Security features in use influence the number of Padding octets. 250 octets total, including the TWAMP format Timeout, Tmax: 3 seconds

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

<for metric, insert relevant section references and supplemental info> The methodology for this metric is defined as Type-P-One-way-Delay-Poisson-Stream in section 3.6 of and section 4.6 of using the Type-P and Timeout defined under Fixed Parameters. The method requires sequence numbers or other send-order information to be retained at the Src or included with each packet to dis-ambiguate packet reordering if it occurs. Sequence number is part of the TWAMP payload described under Fixed Parameters.

This section gives the details of the packet traffic which is the basis for measurement. In IPPM metrics, this is called the Stream, and can easily be dscribed by providing the list of stream parameters. <list of generation parameters and section/spec references if needed> Section 11.1.3 of RFC 2681 provides three methods to generate Poisson sampling intervals. The reciprocal of lambda is the average packet rate, thus the Run-time Parameter is 1/lambda. Method 3 or equivalent SHALL used, where given a start time (Run-time Parameter), the subsequent send times are all computed prior to measurement by computing the pseudo-random distribution of inter-packet send times, (truncating the distribution as specified in the Run-time Parameters), and the Src sends each packet at the computed times.

<lists the names of the different roles from the measurement method> Src - launches each packet and waits for return transmissions from Dst. This is the TWAMP Session-Sender. Dst - waits for each packet from Src and sends a return packet to Src. This is the TWAMP Session-Reflector.

This category specifies all details of the Output of measurements using the metric.

<insert name of the output type, raw or a selected summary statistic> See subsection titles below for Types.

<describe the data format for each type of result> For all output types --- T0, a time (start of measurement interval, 128-bit NTP Date Format, see section 6 of ) Tf, a time (end of measurement interval, 128-bit NTP Date Format, see section 6 of )

The 95th percentile SHALL be calculated using the conditional distribution of all packets with a finite value of One-way delay (undefined delays are excluded), a single value as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. See section 4.3 of for details on the percentile statistic (where Round-trip delay should be substituted for "ipdv"). The percentile = 95. Data format is a 32-bit signed value, *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second.

The mean SHALL be calculated using the conditional distribution of all packets with a finite value of One-way delay (undefined delays are excluded), a single value as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. See section 4.2.2 of for details on calculating this statistic, and 4.2.3 of . Data format is a 32-bit signed value, *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second.

The minimum SHALL be calculated using the conditional distribution of all packets with a finite value of One-way delay (undefined delays are excluded), a single value as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. See section 4.3.2 of for details on calculating this statistic, and 4.3.3 of . Data format is a 32-bit signed value, *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second.

The maximum SHALL be calculated using the conditional distribution of all packets with a finite value of One-way delay (undefined delays are excluded), a single value as follows: See section 4.1 of for details on the conditional distribution to exclude undefined values of delay, and Section 5 of for background on this analysis choice. See section 4.3.2 of for a closely related method for calculating this statistic, and 4.3.3 of . The formula is as follows:

= FiniteDelay[n] for all n]]> Data format is a 32-bit signed value, *similar to* the 32-bit short NTP Time format in Section 6 of and is as follows: the first 16 bits represent the *signed* integer number of seconds; the next 16 bits represent the fractional part of a second.

<pointer to section/spec where output type/format is defined> See the Data Format column for references.

<insert units for the measured results, and the reference specification>. The <statistic> of One-way Delay is expressed in seconds. The 95th Percentile of One-way Delay is expressed in seconds.

name or RFC, etc.

1.0

YYYY-MM-DD

Additional (Informational) details for this entry

This section gives an initial registry entry for the UDP Periodic One-way Delay. Note: Each Registry "Name" below specifies a single registry entry, whose output format varies according to a component of the name that specifies one form of statistical summary. IANA is asked to assign a different numeric identifiers to each Name. All other column entries are the same, thus this section is proposes five closely-related registry entries. As a result, IANA is also asked to assign corresponding URIs and URLs.

This category includes multiple indexes to the registry entries, the element ID and metric name.

<insert name according to metric naming convention> Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_<statistic> OwDelay_Active_IP_UDP_Periodic_UDP_Payload_142_RFCXXXXsecY_Seconds_<statistic> Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_Percentile95 Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_Mean Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_Min Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_Max Act_IP_UDP_Periodic-var_UDP-Payload-142_One-way_Delay_Std_Dev

URI: Prefix urn:ietf:params:performance:metric...<name> URL: http:\\www.iana.org\ ... <name>

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> Type-P: IPv4 header values: DSCP: set to 0 TTL set to 255 Protocol: Set to 17 (UDP) UDP header values: Checksum: the checksum must be calculated UDP Payload: TWAMP Test Packet Formats, Section 4.1.2 of Security features in use influence the number of Padding octets. 142 octets total, including the TWAMP format Timeout, Tmax: 3 seconds

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

This section gives the details of the packet traffic which is the basis for measurement. In IPPM metrics, this is called the Stream, and can easily be dscribed by providing the list of stream parameters. <list of generation parameters and section/spec references if needed> Section 3 of prescribes the method for generating Periodic streams using associated parameters. incT, the nominal duration of inter-packet interval, first bit to first bit dT, the duration of the interval for allowed sample start times T0, the actual start time NOTE: an initiation process with a number of control exchanges resulting in unpredictable start times (within a time interval) may be sufficient to avoid synchronization of periodic streams, and therefore a valid replacement for selecting a start time at random from a fixed interval. These stream parameters will be specified as Run-time parameters.

This category specifies all details of the Output of measurements using the metric.

<insert name of the output type, raw or a selected summary statistic> See subsection titles in Data Format for Types.

<pointer to section/spec where output type/format is defined> See the Data Format column for references.

<insert units for the measured results, and the reference specification>. The <statistic> of One-way Delay is expressed in seconds.

name or RFC, etc.

1.0

YYYY-MM-DD

Additional (Informational) details for this entry

This section gives an initial registry entry for ....

This category includes multiple indexes to the registry entries, the element ID and metric name. <skipping the admin columns for now>

<insert name according to metric naming convention> URL: ??

URI: Prefix urn:ietf:params:performance:metric

TBD.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

<Full bibliographic reference to an immutable doc.> Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip Delay Metric for IPPM", RFC 2681, September 1999. <specific section reference and additional clarifications, if needed> Section 2.4 of provides the reference definition of the singleton (single value) Round-trip delay metric. Section 3.4 of provides the reference definition expanded to cover a multi-value sample. Note that terms such as singleton and sample are defined in Section 11 of . Note that although the definition of "Round-trip-Delay between Src and Dst at T" is directionally ambiguous in the text, this metric tightens the definition further to recognize that the host in the "Src" role will send the first packet to "Dst", and ultimately receive the corresponding return packet from "Dst" (when neither are lost). <<< Check how the Methodology also makes this clear (or not) >>>

<list and specify Fixed Parameters, input factors that must be determined and embedded in the measurement system for use when needed> Type-P: IPv4 header values: DSCP: set to 0 TTL set to 255 Protocol: Set to 17 (UDP) UDP header values: Checksum: the checksum must be calculated Payload Sequence number: 8-byte integer Timestamp: 8 byte integer. Expressed as 64-bit NTP timestamp as per section 6 of RFC 5905 No padding (total of 9 bytes) Timeout: 3 seconds

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

The measured results based on a filtered version of the packets observed, and this section provides the filter details (when present). <section reference>.

This category specifies all details of the Output of measurements using the metric.

<describe the data format for each type of result> Value: Data Format: (There may be some precedent to follow here, but otherwise use 64-bit NTP Timestamp Format, see section 6 of ). Reference: <section reference>

<insert units for the measured results, and the reference specification>.

name or RFC, etc.

1.0

YYYY-MM-DD

Additional (Informational) details for this entry

This section gives an initial registry entry for ....

This category includes multiple indexes to the registry entries, the element ID and metric name. <skipping the Summary columns for now>

<insert name according to metric naming convention> URL: ??

URI: Prefix urn:ietf:params:performance:metric

TBD.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters.

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations.

<insert the measured results based on a filtered version of the packets observed, and this section provides the filter details (when present), and section reference>.

<list of run-time parameters, and any reference(s)>.

This category specifies all details of the Output of measurements using the metric.

<insert units for the measured results, and the reference specification>.

1.0

YYYY-MM-DD

Additional (Informational) details for this entry

This section is MAY BE DELETED or adapted before submission. This section gives an example registry entry for the end-point metric described in RFC 7003 , for RTCP-XR Burst/Gap Discard Metric reporting.

This category includes multiple indexes to the registry entries, the element ID and metric name.

An integer having enough digits to uniquely identify each entry in the Registry.

A metric naming convention is TBD.

Prefix urn:ietf:params:performance:metric

current

Alcelip Mornuley

1.0

2014-07-04

TBD.

This category includes columns to prompt the entry of all necessary details related to the metric definition, including the RFC reference and values of input factors, called fixed parameters. Section 3.2 of provides the reference information for this category.

Packets Discarded in Bursts: The total number of packets discarded during discard bursts. The measured value is unsigned value. If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE MUST be reported to indicate an over-range measurement. If the measurement is unavailable, the value 0xFFFFFF MUST be reported.

Fixed Parameters are input factors that must be determined and embedded in the measurement system for use when needed. The values of these parameters is specified in the Registry. Threshold: 8 bits, set to value = 3 packets. The Threshold is equivalent to Gmin in [RFC3611], i.e., the number of successive packets that must not be discarded prior to and following a discard packet in order for this discarded packet to be regarded as part of a gap. Note that the Threshold is set in accordance with the Gmin calculation defined in Section 4.7.2 of [RFC3611]. Interval Metric flag: 2 bits, set to value 11=Cumulative Duration This field is used to indicate whether the burst/gap discard metrics are Sampled, Interval, or Cumulative metrics [RFC6792]: I=10: Interval Duration - the reported value applies to the most recent measurement interval duration between successive metrics reports. I=11: Cumulative Duration - the reported value applies to the accumulation period characteristic of cumulative measurements. Senders MUST NOT use the values I=00 or I=01.

This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous methods for implementations. For the Burst/Gap Discard Metric, it appears that the only guidance on methods of measurement is in Section 3.0 of and its supporting references. Relevant information is repeated below, although there appears to be no section titled "Method of Measurement" in .

Metrics in this block report on burst/gap discard in the stream arriving at the RTP system. Measurements of these metrics are made at the receiving end of the RTP stream. Instances of this metrics block use the synchronization source (SSRC) to refer to the separate auxiliary Measurement Information Block [RFC6776], which describes measurement periods in use (see [RFC6776], Section 4.2). This metrics block relies on the measurement period in the Measurement Information Block indicating the span of the report. Senders MUST send this block in the same compound RTCP packet as the Measurement Information Block. Receivers MUST verify that the measurement period is received in the same compound RTCP packet as this metrics block. If not, this metrics block MUST be discarded.

Since RTCP-XR Measurements are conducted on live RTP traffic, the complete description of the stream is contained in SDP messages that proceed the establishment of a compatible stream between two or more communicating hosts. See Run-time Parameters, below.

The output type defines the type of result that the metric produces. Value: Packets Discarded in Bursts Data Format: 24 bits Reference: Section 3.2 of

The measured results are apparently expressed in packets, although there is no section of titled "Metric Units".

Run-Time Parameters are input factors that must be determined, configured into the measurement system, and reported with the results for the context to be complete. However, the values of these parameters is not specified in the Registry, rather these parameters are listed as an aid to the measurement system implementor or user (they must be left as variables, and supplied on execution). The Data Format of each Run-time Parameter SHALL be specified in this column, to simplify the control and implementation of measurement devices. SSRC of Source: 32 bits As defined in Section 4.1 of [RFC3611]. SDP Parameters: As defined in [RFC4566] Session description v= (protocol version number, currently only 0) o= (originator and session identifier : username, id, version number, network address) s= (session name : mandatory with at least one UTF-8-encoded character) i=* (session title or short information) u=* (URI of description) e=* (zero or more email address with optional name of contacts) p=* (zero or more phone number with optional name of contacts) c=* (connection information—not required if included in all media) b=* (zero or more bandwidth information lines) One or more Time descriptions ("t=" and "r=" lines; see below) z=* (time zone adjustments) k=* (encryption key) a=* (zero or more session attribute lines) Zero or more Media descriptions (each one starting by an "m=" line; see below) m= (media name and transport address) i=* (media title or information field) c=* (connection information — optional if included at session level) b=* (zero or more bandwidth information lines) k=* (encryption key) a=* (zero or more media attribute lines — overriding the Session attribute lines) An example Run-time SDP description follows: v=0 o=jdoe 2890844526 2890842807 IN IP4 192.0.2.5 s=SDP Seminar i=A Seminar on the session description protocol u=http://www.example.com/seminars/sdp.pdf e=j.doe@example.com (Jane Doe) c=IN IP4 233.252.0.12/127 t=2873397496 2873404696 a=recvonly m=audio 49170 RTP/AVP 0 m=video 51372 RTP/AVP 99 a=rtpmap:99 h263-1998/90000

TBD.

This section may be removed for publication. It contains partial information on updtes. This draft replaced draft-mornuley-ippm-initial-registry. In version 02, Section 4 has been edited to reflect recent discussion on the ippm-list: * Removed the combination or "Raw" and left 95th percentile. * Hanging Indent on Run-time parameters (Fixed parameters use bullet lists and other indenting formats. * Payload format for measurement has been removed. * Explanation of Conditional delay distribution. Version 03 addressed Phil Eardley's comments and suggestions in sections 1-4. and resolved the definition of Percentiles. Version 04 * All section 4 parameters reference YANG types for alternate data formats. * Discussion has concluded that usecase(s) for machine parse-able registry columns are not needed. Still need: * suggestion of standard naming format for parameters. Note: lambda parameter description is correct in section 4, elsewhere needs fix.

These registry entries represent no known security implications for Internet Security. Each referenced Metric contains a Security Considerations section.

IANA is requested to populate The Performance Metric Registry defined in with the values defined above. <more is needed here>

The authors thank Brian Trammell for suggesting the term "Run-time Parameters", which led to the distinction between run-time and fixed parameters implemented in this memo, for identifying the IPFIX metric with Flow Key as an example, and for many other productive suggestions. Thanks to Peter Koch, who provided several useful suggestions for disambiguating successive DNS Queries in the DNS Response time metric. The authors also acknowledge the constructive reviews and helpful suggestions from Barbara Stark, Juergen Schoenwaelder, Tim Carey, and participants in the LMAP working group.