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diff --git a/doc/rfc/rfc6958.txt b/doc/rfc/rfc6958.txt new file mode 100644 index 0000000..b7da404 --- /dev/null +++ b/doc/rfc/rfc6958.txt @@ -0,0 +1,899 @@ + + + + + + +Internet Engineering Task Force (IETF) A. Clark +Request for Comments: 6958 Telchemy +Category: Standards Track S. Zhang +ISSN: 2070-1721 J. Zhao + STTRI + Q. Wu, Ed. + Huawei + May 2013 + + + RTP Control Protocol (RTCP) Extended Report (XR) Block for + Burst/Gap Loss Metric Reporting + +Abstract + + This document defines an RTP Control Protocol (RTCP) Extended Report + (XR) Block that allows the reporting of burst and gap loss metrics + for use in a range of RTP applications. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6958. + +Copyright Notice + + Copyright (c) 2013 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + + +Clark, et al. Standards Track [Page 1] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 + 1.1. Burst/Gap Loss Metrics Block . . . . . . . . . . . . . . 2 + 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . 3 + 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 + 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 3. Burst/Gap Loss Metrics Block . . . . . . . . . . . . . . . . 4 + 3.1. Report Block Structure . . . . . . . . . . . . . . . . . 5 + 3.2. Definition of Fields in Burst/Gap Loss Metrics Block . . 5 + 3.3. Derived Metrics Based on Reported Metrics . . . . . . . . 7 + 4. Considerations for Voice-over-IP Applications . . . . . . . . 8 + 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 9 + 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . 9 + 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . 9 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 + 6.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 9 + 6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9 + 6.3. Contact Information for Registrations . . . . . . . . . . 10 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 + 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 + 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 10.2. Informative References . . . . . . . . . . . . . . . . . 11 + Appendix A. Metrics Represented Using the Template from RFC 6390 13 + +1. Introduction + +1.1. Burst/Gap Loss Metrics Block + + This document defines a new block type to augment those defined in + [RFC3611] for use in a range of RTP applications. The new block type + supports the reporting of the proportion of packets lost by the + network. The losses during loss bursts are reported, together with + the number of bursts and additional data, allowing the calculation of + statistical parameters (mean and variance) of the distribution of + burst lengths. Some uses of these metrics depend on the availability + of the metric "cumulative number of packets lost" from RTCP + [RFC3550]. + + This block provides information on transient IP problems. Burst/gap + metrics are typically used in Cumulative reports; however, they also + may be used in Interval reports. The burstiness of packet loss + affects user experience, may influence any sender strategies to + mitigate the problem, and may also have diagnostic value. + + + + +Clark, et al. Standards Track [Page 2] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + The metric belongs to the class of transport-related end system + metrics defined in [RFC6792]. + + The definitions of "burst", "gap", "loss", and "discard" are + consistent with definitions in [RFC3611]. To accommodate the range + of jitter buffer algorithms and packet discard logic that may be used + by implementors, the method used to distinguish between bursts and + gaps may be an equivalent method to that defined in [RFC3611]. The + method used should produce the same result as that defined in + [RFC3611] for conditions of burst packet loss but may produce + different results for conditions of time-varying jitter. + +1.2. RTCP and RTCP XR Reports + + The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] + defines an extensible structure for reporting by using an RTCP + Extended Report (XR). This document defines a new Extended Report + block for use with [RFC3550] and [RFC3611]. + +1.3. Performance Metrics Framework + + The Performance Metrics Framework [RFC6390] provides guidance on the + definition and specification of performance metrics. The "Guidelines + for Use of the RTP Monitoring Framework" [RFC6792] provides + guidelines for reporting block format using RTCP XR. The Metrics + Block described in this document is in accordance with the guidelines + in [RFC6390] and [RFC6792]. + +1.4. Applicability + + These metrics are applicable to a range of RTP applications that + contain jitter buffers and don't use stream repair means, e.g., + Forward Error Correction (FEC) [RFC5109] and/or retransmission + [RFC4588]. + +2. Terminology + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in RFC 2119 [RFC2119]. + + + + + + + + + + + +Clark, et al. Standards Track [Page 3] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + In addition, the following terms are defined: + + Received, Lost, and Discarded + + A packet shall be regarded as lost if it fails to arrive within an + implementation-specific time window. A packet that arrives within + this time window but is too early or late to be played out or + thrown away before playout due to packet duplication or redundancy + shall be regarded as discarded. A packet shall be classified as + one of received (or OK), discarded, or lost. The metric + "cumulative number of packets lost" defined in [RFC3550] reports a + count of packets lost from the media stream (single + Synchronization Source (SSRC) within a single RTP session). + Similarly, the metric "number of packets discarded" defined in + [DISCARD] reports a count of packets discarded from the media + stream (single SSRC within single RTP session) arriving at the + receiver. The post-repair Loss RLE metric, which is defined in + [RFC5725], can be used to report the number of packets that are + not recovered by any repair techniques that are in use. + + Bursts and Gaps + + The terms "burst" and "gap" are used in a manner consistent with + that of RTCP XR [RFC3611]. RTCP XR views an RTP stream as being + divided into bursts, which are periods when the loss rate is high + enough to cause noticeable quality degradation (generally over 5 + percent loss rate) and gaps, which are periods when lost packets + are infrequent and hence quality is generally acceptable. + +3. Burst/Gap Loss Metrics Block + + Metrics in this block report on burst/gap loss in the stream arriving + at the RTP system. The measurement of these metrics is made at the + receiving end of the RTP stream. Each instance of this Metrics Block + refers by SSRC to a separate auxiliary Measurement Information Block + [RFC6776], which describes the measurement periods in use (see RFC + 6776, 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. + + + + + + + +Clark, et al. Standards Track [Page 4] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +3.1. Report Block Structure + + The structure of the Burst/Gap Loss Metrics Block is as follows. + + 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | BT=20 | I |C| resv. | Block Length = 5 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SSRC of Source | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ -+-+-+-+-+-+-+-+ + | Threshold | Sum of Burst Durations (ms) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Packets Lost in Bursts | Total... | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | ...Packets Expected in Bursts | Number of Bursts | Sum of| + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | ...Squares of Burst Durations (ms-squared) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 1: Report Block Structure + +3.2. Definition of Fields in Burst/Gap Loss Metrics Block + + Block Type (BT): 8 bits + + A Burst/Gap Loss Metrics Block is identified by the constant 20. + + Interval Metric flag (I): 2 bits + + This field is used to indicate whether the burst/gap loss metrics + are Sampled, Interval, or Cumulative metrics: + + 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. + + I=01: Sampled Value - the reported value is a sampled + instantaneous value. + + In this document, burst/gap loss metrics can only be measured over + definite intervals and cannot be sampled. Also, the value I=00 is + reserved for future use. Senders MUST NOT use the values I=00 or + I=01. If a block is received with I=00 or I=01, the receiver MUST + discard the block. + + + +Clark, et al. Standards Track [Page 5] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + Loss and Discard Combination flag (C): 1 bit + + The 'C' flag is used to indicate whether the loss/discard report + is combined with the burst/gap loss report in the same compound + RTCP packet. The value is set to '1' if the loss/discard report + and the burst gap loss report are combined. Otherwise, the value + is set to '0'. If the 'C' flag is set to '1' but the burst/gap + discard was not sent, the receiver MUST discard the burst/gap + loss. + + Reserved (resv.): 5 bits + + These bits are reserved. They MUST be set to zero by senders and + ignored by receivers (see [RFC6709], Section 4.2). + + Block Length: 16 bits + + The length of this report block in 32-bit words, minus one. For + the Burst/Gap Loss Metrics Block, the block length is equal to 5. + The block MUST be discarded if the block length is set to a + different value. + + SSRC of Source: 32 bits + + As defined in Section 4.1 of [RFC3611]. + + Threshold: 8 bits + + The Threshold is equivalent to Gmin in [RFC3611], i.e., the number + of successive packets that must be received prior to and following + a lost packet in order for this lost packet to be regarded as part + of a gap. Note that the threshold is calculated in accordance + with the Gmin Calculation defined in Section 4.7.2 of RFC 3611. + + Sum of Burst Durations (ms): 24 bits + + The total duration of bursts of lost packets in the period of the + report (Interval or Cumulative). + + The measured value is an 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. + + + + + + + + +Clark, et al. Standards Track [Page 6] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + Packets Lost in Bursts: 24 bits + + The total number of packets lost during loss bursts. + + The measured value is an 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. + + Total Packets Expected in Bursts: 24 bits + + The total number of packets expected during loss bursts (that is, + the sum of received packets and lost packets). + + The measured value is an 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. + + Number of Bursts: 16 bits + + The number of bursts in the period of the report (Interval or + Cumulative). + + The measured value is an unsigned value. If the measured value + exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an + over-range measurement. If the measurement is unavailable, the + value 0xFFFF MUST be reported. + + Sum of Squares of Burst Durations (ms-squared): 36 bits + + The sum of the squares of burst durations (where individual burst + durations are expressed in ms) in the period of the report + (Interval or Cumulative). The units for this quantity are + milliseconds-squared. + + The measured value is an unsigned value. If the measured value + exceeds 0xFFFFFFFFD, the value 0xFFFFFFFFE MUST be reported to + indicate an over-range measurement. If the measurement is + unavailable, the value 0xFFFFFFFFF MUST be reported. + +3.3. Derived Metrics Based on Reported Metrics + + The metrics described here are intended to be used as described in + this section, in conjunction with information from the Measurement + Information Block [RFC6776] and also with the metric "cumulative + number of packets lost" provided in standard RTCP [RFC3550]. + + + + +Clark, et al. Standards Track [Page 7] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + These metrics provide information relevant to statistical parameters, + including: + + o the fraction of packets lost during bursts (i.e., Burst Loss Rate + in [SUMSTAT]), which can be calculated using the metric "Packets + Loss in Bursts" and the metric "Total Packets Expected in Bursts" + provided in the Burst/Gap Loss Metrics Block. + + o the fraction of packets lost during gaps (i.e., Gap Loss Rate in + [SUMSTAT]), which can be calculated using the metric "Packets Loss + in Bursts" and the metric "Total Packets Expected in Bursts" + provided in the Burst/Gap Loss Metrics Block. + + o burst duration mean [SUMSTAT], which can be calculated using the + metric "Packets Loss in Bursts" and the metric "Total Packets + Expected in Bursts" provided in the Burst/Gap Loss Metrics Block. + + o burst duration variance [SUMSTAT], which can be calculated using + the metric "Packets Loss in Bursts" and the metric "Total Packets + Expected in Bursts" provided in the Burst/Gap Loss Metrics Block. + + The details on calculation of these parameters in the metrics are + described in [SUMSTAT]. + +4. Considerations for Voice-over-IP Applications + + This Metrics Block is applicable to a broad range of RTP + applications. Where the metric is used with a Voice-over-IP (VoIP) + application and the stream repair means is not available, the + following considerations apply. + + RTCP XR views a call as being divided into bursts, which are periods + when the loss rate is high enough to cause noticeable call quality + degradation (generally over 5 percent loss rate), and gaps, which are + periods when lost packets are infrequent and hence call quality is + generally acceptable. + + If Voice Activity Detection is used, the Burst and Gap Durations + shall be determined as if silence packets had been sent, i.e., a + period of silence in excess of Gmin packets will terminate a burst + condition. + + The recommended value for the threshold Gmin in [RFC3611] causes a + burst during which the call quality is degraded to a similar extent + as it would be during a typical Pulse Code Modulation (PCM) Severely + Errored Second. + + + + + +Clark, et al. Standards Track [Page 8] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +5. SDP Signaling + + [RFC3611] defines the use of the Session Description Protocol (SDP) + [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used + without prior signaling. + +5.1. SDP rtcp-xr-attrib Attribute Extension + + This section augments the SDP [RFC4566] attribute "rtcp-xr" defined + in [RFC3611] by providing an additional value of "xr-format" to + signal the use of the report block defined in this document. The + ABNF [RFC5234] syntax is below. + + xr-format =/ xr-bgl-block + + xr-bgl-block = "burst-gap-loss" + +5.2. Offer/Answer Usage + + When SDP is used in the offer/answer context, the SDP Offer/Answer + usage defined in [RFC3611] for unilateral "rtcp-xr" attribute + parameters applies. For detailed usage of offer/answer for + unilateral parameters, refer to Section 5.2 of [RFC3611]. + +6. IANA Considerations + + New block types for RTCP XR are subject to IANA registration. For + general guidelines on IANA considerations for RTCP XR, refer to + [RFC3611]. + +6.1. New RTCP XR Block Type Value + + This document assigns the block type value 20 in the IANA "RTP + Control Protocol Extended Reports (RTCP XR) Block Type Registry" to + the "Burst/Gap Loss Metrics Block". + +6.2. New RTCP XR SDP Parameter + + This document also registers a new parameter "burst-gap-loss" in the + "RTP Control Protocol Extended Reports (RTCP XR) Session Description + Protocol (SDP) Parameters Registry". + + + + + + + + + + +Clark, et al. Standards Track [Page 9] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +6.3. Contact Information for Registrations + + The contact information for the registrations is: + + Qin Wu (sunseawq@huawei.com) + + 101 Software Avenue, Yuhua District + Nanjing, Jiangsu 210012 + China + +7. Security Considerations + + This block does not provide per-packet statistics, so the risk to + confidentiality documented in Section 7, paragraph 3 of [RFC3611] + does not apply. However, the gaps indicated within this block could + be used to detect the timing of other events on the path between the + sender and receiver. For example, a competing multimedia stream + might cause a loss burst for the duration of the stream, allowing the + receiver of this block to know when the competing stream was active. + This risk is not a significant threat since the only information + leaked is the timing of the loss, not the cause. Besides this, it is + believed that this proposed RTCP XR report block introduces no other + new security considerations beyond those described in [RFC3611]. + +8. Contributors + + Geoff Hunt wrote the initial draft of this document. + +9. Acknowledgments + + The authors gratefully acknowledge reviews and feedback provided by + Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor, + Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, + Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, + Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi + Raviraj, Albrecht Schwarz, Tom Taylor, Hideaki Yamada, Adam Roach, + Dan Romascanu, Chris Lonvick, Alfred C. Morton Jr., Pete Resnick, Ted + Lemon, Stephen Farrell, Richard Barnes, and Benoit Claise. + + + + + + + + + + + + + +Clark, et al. Standards Track [Page 10] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +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. + + [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. + Jacobson, "RTP: A Transport Protocol for Real-Time + Applications", STD 64, RFC 3550, July 2003. + + [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control + Protocol Extended Reports (RTCP XR)", RFC 3611, November + 2003. + + [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session + Description Protocol", RFC 4566, July 2006. + + [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax + Specifications: ABNF", STD 68, RFC 5234, January 2008. + + [RFC5725] Begen, A., Hsu, D., and M. Lague, "Post-Repair Loss RLE + Report Block Type for RTP Control Protocol (RTCP) Extended + Reports (XRs)", RFC 5725, February 2010. + +10.2. Informative References + + [DISCARD] Clark, A., Huang, R., and Q. Wu, Ed., "RTP Control + Protocol (RTCP) Extended Report (XR) Block for Discard + Count metric Reporting", Work in Progress, April 2013. + + [RFC4588] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. + Hakenberg, "RTP Retransmission Payload Format", RFC 4588, + July 2006. + + [RFC5109] Li, A., "RTP Payload Format for Generic Forward Error + Correction", RFC 5109, December 2007. + + [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New + Performance Metric Development", BCP 170, RFC 6390, + October 2011. + + [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design + Considerations for Protocol Extensions", RFC 6709, + September 2012. + + + + + + +Clark, et al. Standards Track [Page 11] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + [RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information + Reporting Using a Source Description (SDES) Item and an + RTCP Extended Report (XR) Block", RFC 6776, October 2012. + + [RFC6792] Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the + RTP Monitoring Framework", RFC 6792, November 2012. + + [SUMSTAT] Zorn, G., Schott, R., Wu, Q., Ed., and R. Huang, "RTP + Control Protocol (RTCP) Extended Report (XR) Blocks for + Summary Statistics Metrics Reporting", Work in Progress, + March 2013. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Clark, et al. Standards Track [Page 12] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +Appendix A. Metrics Represented Using the Template from RFC 6390 + + The six metrics defined in this document are described below using + the template from Section 5.4.4 of RFC 6390. + + a. Threshold Metric + + * Metric Name: Threshold in RTP + + * Metric Description: The Threshold is equivalent to Gmin in + [RFC3611], i.e., the number of successive RTP packets that + must be received prior to and following a lost RTP packet in + order for this lost RTP packet to be regarded as part of a + gap. + + * Method of Measurement or Calculation: See Section 3.2, + Threshold definition. + + * Units of Measurement: See Section 3.2, Threshold definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + * Use and Applications: See Section 1.4. + + * Reporting Model: See RFC 3611. + + b. Sum of Burst Durations Metric + + * Metric Name: Sum of Burst Durations in RTP + + * Metric Description: The total duration of bursts of lost RTP + packets in the period of the report. + + * Method of Measurement or Calculation: See Section 3.2, Sum of + Burst Durations definition. + + * Units of Measurement: See Section 3.2, Sum of Burst Durations + definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + + +Clark, et al. Standards Track [Page 13] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + * Use and Applications: See Section 1.4. + + * Reporting Model: See RFC 3611. + + c. Packets Lost in Bursts Metric + + * Metric Name: RTP Packets lost in bursts + + * Metric Description: The total number of RTP packets lost + during loss bursts. + + * Method of Measurement or Calculation: See Section 3.2, Packets + Lost in Bursts definition. + + * Units of Measurement: See Section 3.2, Packets lost in bursts + definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + * Use and Applications: See Section 1.4. + + * Reporting Model: See RFC 3611. + + d. Total Packets Expected in Bursts Metric + + * Metric Name: Total RTP packets expected in bursts + + * Metric Description: The total number of RTP packets expected + during loss bursts (that is, the sum of received RTP packets + and lost RTP packets). + + * Method of Measurement or Calculation: See Section 3.2, Total + packets expected in bursts definition. + + * Units of Measurement: See Section 3.2, Total packets expected + in bursts definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + * Use and Applications: See Section 1.4. + + + +Clark, et al. Standards Track [Page 14] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + + * Reporting Model: See RFC 3611. + + e. Number of Bursts Metric + + * Metric Name: Number of bursts in RTP + + * Metric Description: The total duration of bursts of lost RTP + packets in the period of the report. + + * Method of Measurement or Calculation: See Section 3.2, Number + of bursts definition. + + * Units of Measurement: See Section 3.2, Number of bursts + definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + * Use and Applications: See Section 1.4. + + * Reporting Model: See RFC 3611. + + f. Sum of Squares of Burst Durations Metric + + * Metric Name: Sum of Squares of Burst Durations in RTP + + * Metric Description: The sum of the squares of burst durations + (where individual burst durations are expressed in ms) over in + the period of the report. + + * Method of Measurement or Calculation: See Section 3.2, Sum of + Squares of Burst Durations definition. + + * Units of Measurement: See Section 3.2, Sum of Squares of Burst + Durations definition. + + * Measurement Point(s) with Potential Measurement Domain: See + Section 3, 1st paragraph. + + * Measurement Timing: See Section 3, 2nd paragraph for + measurement timing and Section 3.2 for Interval Metric flag. + + * Use and Applications: See Section 1.4. + + * Reporting Model: See RFC 3611. + + + +Clark, et al. Standards Track [Page 15] + +RFC 6958 RTCP XR Burst/Gap Loss May 2013 + + +Authors' Addresses + + Alan Clark + Telchemy Incorporated + 2905 Premiere Parkway, Suite 280 + Duluth, GA 30097 + USA + + EMail: alan.d.clark@telchemy.com + + + Sunshine Zhang + Shanghai Research Institute of China Telecom Corporation Limited + No. 1835, South Pudong Road + Shanghai 200122 + China + + EMail: zhangyx@sttri.com.cn + + + Jing Zhao + Shanghai Research Institute of China Telecom Corporation Limited + No. 1835, South Pudong Road + Shanghai 200122 + China + + EMail: zhaojing@sttri.com.cn + + + Qin Wu (editor) + Huawei + 101 Software Avenue, Yuhua District + Nanjing, Jiangsu 210012 + China + + EMail: sunseawq@huawei.com + + + + + + + + + + + + + + + +Clark, et al. Standards Track [Page 16] + |