OWPDV_Active_IP-UDP-Periodic_RFC8912sec5_Seconds_95Percentile All section numbers below refer to RFC 8912 5.1. Summary    This category includes multiple indexes to the Registry Entry: the     element ID and Metric Name. 5.1.1. ID (Identifier)    3 5.1.2. Name    OWPDV_Active_IP-UDP-Periodic_RFC8912sec5_Seconds_95Percentile 5.1.3. URI    URL: https://www.iana.org/assignments/performance-metrics/OWPDV_Active_IP-UDP-Periodic_RFC8912sec5_Seconds_95Percentile 5.1.4. Description    This metric assesses packet delay variation with respect to the     minimum delay observed on the periodic stream. The output is     expressed as the 95th percentile of the one-way packet delay     variation distribution. 5.1.5. Change Controller    IETF 5.1.6. Version (of Registry Format)    1.0 5.2. Metric Definition    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". 5.2.1. Reference Definition    Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP     Performance Metrics", RFC 2330, DOI 10.17487/RFC2330, May 1998,     . [RFC2330]    Demichelis, C. and P. Chimento, "IP Packet Delay Variation Metric     for IP Performance Metrics (IPPM)", RFC 3393, DOI 10.17487/RFC3393,     November 2002, . [RFC3393]    Morton, A. and B. Claise, "Packet Delay Variation Applicability     Statement", RFC 5481, DOI 10.17487/RFC5481, March 2009,     . [RFC5481]    Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time     Protocol Version 4: Protocol and Algorithms Specification", RFC 5905,     DOI 10.17487/RFC5905, June 2010, .     [RFC5905]    See Sections 2.4 and 3.4 of [RFC3393]. The measured singleton delay     differences 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 [RFC5481], where the singleton PDV for     packet i is referred to by the variable name "PDV(i)". 5.2.2. Fixed Parameters    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       Next Header: Set to 17 (UDP)       Flow Label: Set to 0       Extension Headers: None        UDP header values:       Checksum: The checksum MUST be calculated and the non-zero        checksum included in the header    UDP Payload:       Total of 200 bytes Other measurement Parameters:    Tmax: A loss threshold waiting time with value 3.0, expressed in units     of seconds, as a positive value of type decimal64 with fraction digits     = 4 (see Section 9.3 of [RFC6020]) and with a resolution of 0.0001     seconds (0.1 ms), with lossless conversion to/from the 32-bit NTP     timestamp as per Section 6 of [RFC5905].    F: A selection function unambiguously defining the packets from the     stream selected for the metric. See Section 4.2 of [RFC5481] for the     PDV form.    See the Packet Stream Generation section for two additional     Fixed Parameters. 5.3. Method of Measurement    This category includes columns for references to relevant sections of     the RFC(s) and any supplemental information needed to ensure an unambiguous     method for implementations. 5.3.1. Reference Methods    See Sections 2.6 and 3.6 of [RFC3393] for general singleton element     calculations. This Metric Entry requires implementation of the PDV     form defined in Section 4.2 of [RFC5481]. Also see measurement     considerations in Section 8 of [RFC5481].    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 that     calculates the one-way delay value MUST enforce the Tmax threshold     on stored values before calculations. See Section 4.1 of [RFC3393]     for details on the conditional distribution to exclude undefined     values of delay, and see Section 5 of [RFC6703] 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 disambiguate     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 timestamps, if they are conveyed in the     packet payload. 5.3.2. Packet Stream Generation    This section provides details regarding packet traffic, which is used     as the basis for measurement. In IPPM Metrics, this is called the     "stream"; this stream can easily be described by providing the list     of stream Parameters.    Section 3 of [RFC3432] prescribes the method for generating Periodic    streams using associated Parameters.    incT: The nominal duration of the inter-packet interval, first bit to     first bit, with value 0.0200, expressed in units of seconds, as a     positive value of type decimal64 with fraction digits = 4 (see Section     9.3 of [RFC6020]) and with a resolution of 0.0001 seconds (0.1 ms).    dT: The duration of the interval for allowed sample start times, with     value 1.0, expressed in units of seconds, as a positive value of type     decimal64 with fraction digits = 4 (see Section 9.3 of [RFC6020]) and     with a resolution of 0.0001 seconds (0.1 ms).       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 is a valid replacement        for selecting a start time at random from a fixed interval.    The T0 Parameter will be reported as a measured Parameter. Parameters incT     and dT are Fixed Parameters. 5.3.3. Traffic Filtering (Observation) Details    N/A 5.3.4. Sampling Distribution    N/A 5.3.5. Runtime Parameters and Data Format    Src: 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 [RFC6991]).    Dst: 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 [RFC6991]).    T0: A time, the start of a measurement interval (format "date‑time"     as specified in Section 5.6 of [RFC3339]; see also "date‑and‑time" in     Section 3 of [RFC6991]). The UTC Time Zone is required by Section 6.1     of [RFC2330]. 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.    Tf: A time, the end of a measurement interval (format "date‑time" as     specified in Section 5.6 of [RFC3339]; see also "date‑and‑time" in     Section 3 of [RFC6991]). The UTC Time Zone is required by Section 6.1     of [RFC2330]. When T0 is "all-zeros", an ending time and date is     ignored and Tf is interpreted as the duration of the measurement     interval. 5.3.6. Roles    Src: Launches each packet and waits for return transmissions from the Dst.    Dst: Waits for each packet from the Src and sends a return packet to the     Src (when required by the test protocol). 5.4. Output    This category specifies all details of the output of measurements using     the metric. 5.4.1. Type    Percentile: For the conditional distribution of all packets with a valid     value of one-way delay (undefined delays are excluded), this is a single     value corresponding to the 95th percentile, as follows:    See Section 4.1 of [RFC3393] for details on the conditional distribution     to exclude undefined values of delay, and see Section 5 of [RFC6703] for     background on this analysis choice.    The percentile = 95, meaning that the reported delay, "95Percentile", is     the smallest value of one-way PDV for which the Empirical Distribution     Function, EDF(95Percentile), is greater than or equal to 95% of the     singleton one-way PDV values in the conditional distribution. See     Section 11.3 of [RFC2330] for the definition of the percentile statistic     using the EDF. 5.4.2. Reference Definition    T0: The start of a measurement interval (format "date‑time" as specified     in Section 5.6 of [RFC3339]; see also "date‑and‑time" in Section 3 of     [RFC6991]). The UTC Time Zone is required by Section 6.1 of [RFC2330].    Tf: The end of a measurement interval (format "date‑time" as specified     in Section 5.6 of [RFC3339]; see also "date‑and‑time" in Section 3 of     [RFC6991]). The UTC Time Zone is required by Section 6.1 of [RFC2330].    95Percentile: 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 [RFC6020]) with a resolution of     0.000000001 seconds (1.0 ns), and with lossless conversion to/from the     64-bit NTP timestamp as per Section 6 of [RFC5905]. 5.4.3. Metric Units    The 95th percentile of one-way PDV is expressed in seconds. 5.4.4. Calibration    Section 3.7.3 of [RFC7679] provides a means to quantify the systematic     and random errors of a time measurement. Calibration in-situ could be     enabled with an internal loopback that includes as much of the     measurement system as possible, performs address manipulation as needed,     and provides some form of isolation (e.g., deterministic delay) to     avoid send-receive interface contention. Some portion of the random and     systematic error can be characterized in this way.    For one-way delay measurements, the error calibration must include an     assessment of the internal clock synchronization with its external     reference (this internal clock is supplying timestamps for measurement).     In practice, the time offsets [RFC5905] of clocks at both the Source     and Destination are needed to estimate the systematic error due to     imperfect clock synchronization (the time offsets are smoothed; thus,     the random variation is not usually represented in the results).    time_offset: The time value of the result is expressed in units of seconds,     as a signed value of type decimal64 with fraction digits = 9 (see Section     9.3 of [RFC6020]) with a resolution of 0.000000001 seconds (1.0 ns), and     with lossless conversion to/from the 64-bit NTP timestamp as per     Section 6 of [RFC5905].    When a measurement controller requests a calibration measurement, the     loopback is applied and the result is output in the same format as a     normal measurement, with an additional indication that it is a calibration     result. In any measurement, the measurement function SHOULD report its     current estimate of the time offset [RFC5905] as an indicator of the     degree of synchronization.    Both internal loopback calibration and clock synchronization can be used     to estimate the available accuracy of the Output Metric Units. For example,     repeated loopback delay measurements will reveal the portion of the     output result resolution that is the result of system noise and is thus     inaccurate. 5.5. Administrative Items 5.5.1. Status    Current 5.5.2. Requester    RFC 8912 5.5.3. Revision    1.0 5.5.4. Revision Date    2021-11-17 5.6. Comments and Remarks    Lost packets represent a challenge for delay variation metrics.     See Section 4.1 of [RFC3393] and the delay variation applicability     statement [RFC5481] for extensive analysis and comparison of PDV     and an alternate metric, IPDV (Inter-Packet Delay Variation).