[ippm] Re: [bmwg] New ID: Considerations for Interpret ing Packet Loss Observed by Active Performance Measurements
Libin Liu <[email protected]> Fri, 24 Jul 2026 07:08:08 +0000
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--===============8354606633942886223== Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_TY4PR01MB12668D750000AC86698CB5E1EE2CF2TY4PR01MB12668jp_" --_000_TY4PR01MB12668D750000AC86698CB5E1EE2CF2TY4PR01MB12668jp_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Hi Tim, > I think this is useful work, applicable to many tools that would come out= of the new joint bpm WG. [Libin:] Thank you very much for your feedback. > The question is where it fits - there or, presumably, the catchall opsawg= . > The bpm charter is still bashable. You can propose an edit to clarify th= e applicability of your work at https://github.com/ietf-ippm/wg-charter/blo= b/main/ippm-bmwg-joint.md. The wg would need to agree that interpretation/= troubleshooting informational/guidance documents are in scope. If we=92re = including security / sensitivity perspectives, it could be. [Libin:] Thank you very much for the suggestions. Glad to have a chance to = discuss the charter now. I am going to propose an edit to the bpm charter. Best, Libin ________________________________ From: Tim Chown <[email protected]> Sent: Thursday, July 23, 2026 5:48 PM To: Libin Liu <[email protected]>; [email protected] <Ruediger.G= [email protected]> Cc: [email protected] <[email protected]>; [email protected] <[email protected]> Subject: Re: [bmwg] New ID: Considerations for Interpreting Packet Loss Obs= erved by Active Performance Measurements Hi, I think this is useful work, applicable to many tools that would come out o= f the new joint bpm WG. The question is where it fits - there or, presumabl= y, the catchall opsawg. The bpm charter is still bashable. You can propose an edit to clarify the = applicability of your work at https://github.com/ietf-ippm/wg-charter/blob/= main/ippm-bmwg-joint.md. The wg would need to agree that interpretation/tr= oubleshooting informational/guidance documents are in scope. If we=92re in= cluding security / sensitivity perspectives, it could be. Tim On 23/07/2026, 11:39, "Libin Liu" <[email protected]> wrote: Hi Ruediger, Thank you very much for your feedback and for raising this question for dis= cussion. Given the close relationship between measurement results and their interpre= tation, I believe IPPM (or BMP WG later) is a natural venue for this work, = and I hope to continue developing it within the WG. At the same time, I app= reciate the opportunity to hear the views of the WG members about this, and= I am open to further input and review. Thanks. Best, Libin ________________________________ From: [email protected] <[email protected]> Sent: Thursday, July 23, 2026 4:59 PM To: [email protected] <[email protected]> Cc: [email protected] <[email protected]>; [email protected] <[email protected]> Subject: AW: [bmwg] New ID: Considerations for Interpreting Packet Loss Obs= erved by Active Performance Measurements Hi Libin, thanks for your draft. The draft discusses the topic quite well, I think. The question I have is addressed to the chairs and community: IPPM is chart= ered to specify metrics and metric measurement metrics. Your draft regards = result interpretation. - interpreting results is the reason, why measurements are collected. - is IPPM (or another IETF WG; if yes, which one) chartered for documentati= on or standardization of doc=92s as your draft? As my point isn=92t related to content and rather an organizational questio= n, I appreciate feedback of others who may be interested in the subject (co= ntent of your draft). Regards, Ruediger Von: Libin Liu <[email protected]> Gesendet: Dienstag, 14. Juli 2026 03:54 An: ippm <[email protected]>; bmwg <[email protected]> Betreff: [ippm] Fw: [bmwg] New ID: Considerations for Interpreting Packet L= oss Observed by Active Performance Measurements Dear All, Following my previous email, I would like to share a more detailed set of s= lides introducing draft-liu-ippm-active-loss-considerations. The presentati= on provides more background on the motivation, the interpretation problem, = and the overall framework discussed in the draft. The slides are available in the GitHub repo: https://github.com/LibinLiu018= 9/draft-ippm-active-loss-considerations/blob/main/slides-ippm-active-loss-c= onsiderations-00.pdf If the topic is of interest, I would appreciate any comments or feedback. I= would also be happy to discuss the work, either in Vienna during IETF 126 = or online. Thank you very much. Best, Libin ________________________________ From: Libin Liu <liulb=3D40zgclab.edu.cn-Tr9gZwTxerDR74oF6e/[email protected]<mailto:liulb=3D40zg= clab.edu.cn-Tr9gZwTxerDR74oF6e/[email protected]>> Sent: Thursday, July 2, 2026 9:30 AM To: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]= >>; [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]= >> Subject: [bmwg] New ID: Considerations for Interpreting Packet Loss Observe= d by Active Performance Measurements Dear All, I would like to draw your attention to a new draft that has recently been s= ubmitted: draft-liu-ippm-active-measurement-loss-considerations-00. This document discusses considerations for interpreting packet loss observe= d by active performance measurements. While measurement protocols and metri= cs accurately report observable outcomes such as packet loss, missing respo= nses, delay, and delay variation, these observations alone often do not rev= eal the underlying operational cause. Similar measurement results may arise= from different conditions, including congestion, forwarding failures, rout= ing changes, filtering policies, endpoint behavior, multipath forwarding, o= r validation-related packet discard. The document proposes a common interpretation framework that distinguishes = measured outcomes from inferred causes. It discusses how different operatio= nal conditions may affect the interpretation of packet loss, delay, and del= ay variation in active performance measurements, including one-way and two-= way measurements, OWAMP, TWAMP, STAMP, and measurements over ECMP and link = aggregation. The document also discusses how additional operational context= may assist operators and measurement systems in reasoning about possible e= xplanations for observed measurement results. The draft is available here: = https://datatracker.ietf.org/doc/draft-liu-ippm-active-loss-considerations/= . The GitHub repository for the draft is also available here for issues, co= mments, and pull requests: https://github.com/LibinLiu0189/draft-ippm-activ= e-loss-considerations. Comments, suggestions, and discussions would be greatly appreciated. I woul= d also be interested to hear whether similar interpretation challenges have= been encountered in operational deployments or existing measurement system= s, and whether there are additional scenarios that should be considered in = the document. Thank you very much. Best, Libin > -----Original Messages----- > From: [email protected]<mailto:[email protected]> > Send time:Wednesday, 01/07/2026 17:09:28 > To: "Libin Liu" <[email protected]<mailto:[email protected]>> > Subject: New Version Notification for draft-liu-ippm-active-loss-consider= ations-00.txt > > A new version of Internet-Draft > draft-liu-ippm-active-loss-considerations-00.txt has been successfully > submitted by Libin Liu and posted to the > IETF repository. > > Name: draft-liu-ippm-active-loss-considerations > Revision: 00 > Title: Considerations for Interpreting Packet Loss Observed by Active = Performance Measurements > Date: 2026-07-01 > Group: Individual Submission > Pages: 30 > URL: https://www.ietf.org/archive/id/draft-liu-ippm-active-loss-cons= iderations-00.txt > Status: https://datatracker.ietf.org/doc/draft-liu-ippm-active-loss-con= siderations/ > HTML: https://www.ietf.org/archive/id/draft-liu-ippm-active-loss-cons= iderations-00.html > HTMLized: https://datatracker.ietf.org/doc/html/draft-liu-ippm-active-los= s-considerations > > > Abstract: > > Active performance measurement protocols and metrics are commonly > used to measure packet loss, delay, delay variation, reachability, > and path behavior. When an active measurement packet is not > received, a response is missing, or a measurement exchange times out, > the measurement result identifies the observable outcome but often > does not identify the underlying cause. > > Loss observed by active performance measurements can be associated > with congestion, queue discard, link or forwarding failures, routing > changes, endpoint or reflector behavior, administrative filtering, > policing, multipath effects, or validation-related packet discard > such as Source Address Validation (SAV). Different operational > conditions can produce similar measurement observations, but they may > have different meanings and require different troubleshooting > actions. > > This document discusses considerations for interpreting packet loss > observed by active performance measurements. It provides a common > set of considerations for separating measured outcomes from inferred > causes, describes operational conditions that can lead to observed > loss, discusses implications for one-way and two-way measurements, > delay and delay variation interpretation, OWAMP, TWAMP, STAMP, and > measurements over ECMP and link aggregation. It also discusses how > some considerations may apply to hybrid and passive performance > measurements and identifies sources of operational context that can > help operators and measurement systems reason about possible > explanations. > > > > The IETF Secretariat > _______________________________________________ bmwg mailing list -- [email protected]<mailto:[email protected]> To unsubscribe send an email to [email protected]<mailto:bmwg-leave@ietf.= org> --_000_TY4PR01MB12668D750000AC86698CB5E1EE2CF2TY4PR01MB12668jp_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable <html> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3DWindows-1= 252"> <style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo= ttom:0;} </style> </head> <body dir=3D"ltr"> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> Hi Tim,</div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> > I think this is useful work, applicable to many tools that would come = out of the new joint bpm WG. </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> [Libin:] Thank you very much for your feedback.</div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> > The question is where it fits - there or, presumably, the catchall ops= awg.</div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> > The bpm charter is still bashable. You can propose an edit to cl= arify the applicability of your work at <a href=3D"https://github.com/ietf-ippm/wg-charter/blob/main/ippm-bmwg-join= t.md" id=3D"OWAeca030c6-dcbe-2df0-a1c3-71cae5834c34" class=3D"OWAAutoLink"> <u>https://github.com/ietf-ippm/wg-charter/blob/main/ippm-bmwg-joint.md</u>= </a>. The wg would need to agree that interpretation/troubleshooting = informational/guidance documents are in scope. If we=92re including s= ecurity / sensitivity perspectives, it could be.</div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> [Libin:] Thank you very much for the suggestions. Glad to have a chance to = discuss the charter now. I am going to propose an edit to the bpm charter.<= /div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; mi= n-height: 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService= , Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> Best,</div> <div class=3D"elementToProof" style=3D"line-height: normal; margin: 0px; fo= nt-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helveti= ca, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> Libin</div> <div style=3D"font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, = Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <hr style=3D"display: inline-block; width: 98%;"> <div id=3D"divRplyFwdMsg"> <div style=3D"direction: ltr; font-family: Calibri, sans-serif; font-size: = 11pt; color: rgb(0, 0, 0);"> <b>From:</b> Tim Chown <[email protected]><br> <b>Sent:</b> Thursday, July 23, 2026 5:48 PM<br> <b>To:</b> Libin Liu <[email protected]>; [email protected]= e <[email protected]><br> <b>Cc:</b> [email protected] <[email protected]>; [email protected] <bmwg@ietf= .org><br> <b>Subject:</b> Re: [bmwg] New ID: Considerations for Interpreting Packet L= oss Observed by Active Performance Measurements</div> <div style=3D"direction: ltr;"> </div> </div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> Hi,</div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> I think this is useful work, applicable to many tools that would come out o= f the new joint bpm WG. The question is where it fits - there or, presumabl= y, the catchall opsawg.</div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> The bpm charter is still bashable. You can propose an edit to clarify= the applicability of your work at <a href=3D"https://github.com/ietf-ippm/wg-charter/blob/main/ippm-bmwg-join= t.md" id=3D"OWA8147b543-2456-6747-e979-b8b55d3b9529" class=3D"OWAAutoLink" = data-auth=3D"NotApplicable" data-outlook-id=3D"1ac34ac2-f698-4dfc-bc59-c82e= 652d1a0f"> https://github.com/ietf-ippm/wg-charter/blob/main/ippm-bmwg-joint.md</a>. &= nbsp;The wg would need to agree that interpretation/troubleshooting informa= tional/guidance documents are in scope. If we=92re including security= / sensitivity perspectives, it could be.</div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> Tim</div> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div id=3D"x_mail-editor-reference-message-container"> <div>On 23/07/2026, 11:39, "Libin Liu" <[email protected]&= gt; wrote:</div> <div style=3D"direction: ltr;"><br> </div> <div style=3D"line-height: normal; margin: 0px; font-family: Aptos, Aptos_E= mbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size= : 12pt; color: rgb(0, 0, 0);"> Hi Ruediger,</div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; font-family= : Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-= serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"line-height: normal; margin: 0px; font-family: Aptos, Aptos_E= mbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size= : 12pt; color: rgb(0, 0, 0);"> Thank you very much for your feedback and for raising this question for dis= cussion.</div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; min-height:= 15px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri= , Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"line-height: normal; margin: 0px; font-family: Aptos, Aptos_E= mbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size= : 12pt; color: rgb(0, 0, 0);"> Given the close relationship between measurement results and their interpre= tation, I believe IPPM (or BMP WG later) is a natural venue for this work, = and I hope to continue developing it within the WG. At the same time, I app= reciate the opportunity to hear the views of the WG members about this, and I am open to further input and= review. Thanks.</div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; font-family= : Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-= serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; font-family= : Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-= serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; font-family= : Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-= serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style=3D"line-height: normal; margin: 0px; font-family: Aptos, Aptos_E= mbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size= : 12pt; color: rgb(0, 0, 0);"> Best,<br> Libin</div> <div style=3D"direction: ltr; line-height: normal; margin: 0px; font-family= : Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-= serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <hr style=3D"display: inline-block; width: 98%;"> <div id=3D"x_divRplyFwdMsg"> <div style=3D"direction: ltr; font-family: Calibri, sans-serif; font-size: = 11pt; color: rgb(0, 0, 0);"> <b>From:</b> [email protected] <[email protected]>= <br> <b>Sent:</b> Thursday, July 23, 2026 4:59 PM<br> <b>To:</b> [email protected] <[email protected]><br> <b>Cc:</b> [email protected] <[email protected]>; [email protected] <bmwg= @ietf.org><br> <b>Subject:</b> AW: [bmwg] New ID: Considerations for Interpreting Pac= ket Loss Observed by Active Performance Measurements</div> <div style=3D"direction: ltr;"> </div> </div> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= Hi Libin,</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= thanks for your draft. The draft discusses the topic quite well, I think.</= p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= The question I have is addressed to the chairs and community: IPPM is chart= ered to specify metrics and metric measurement metrics. Your draft regards = result interpretation.</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= - interpreting results is the reason, why measurements are collected.</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= - is IPPM (or another IETF WG; if yes, which one) chartered for documentati= on or standardization of doc=92s as your draft?</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= As my point isn=92t related to content and rather an organizational questio= n, I appreciate feedback of others who may be interested in the subject (co= ntent of your draft).</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= Regards,</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= Ruediger</p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <div style=3D"padding: 3pt 0cm 0cm; border-top: 1pt solid rgb(225, 225, 225= );"> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"font-family: Calibri, sans-serif; font-size: 11pt;"><b>Von:<= /b> Libin Liu <[email protected]><br> <b>Gesendet:</b> Dienstag, 14. Juli 2026 03:54<br> <b>An:</b> ippm <[email protected]>; bmwg <[email protected]><br> <b>Betreff:</b> [ippm] Fw: [bmwg] New ID: Considerations for Interpret= ing Packet Loss Observed by Active Performance Measurements</span></p> </div> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">Dear All,</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">Following my previous email, I would like to = share a more detailed set of slides introducing draft-liu-ippm-active-loss-= considerations. The presentation provides more background on the motivation, the interpretation problem, and the ove= rall framework discussed in the draft.</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">The slides are available in the GitHub repo: </span><span style=3D"color: blue;"><a href=3D"https://github.com/LibinLiu0= 189/draft-ippm-active-loss-considerations/blob/main/slides-ippm-active-loss= -considerations-00.pdf" id=3D"OWA3ca08547-3966-d5d0-5fbc-13e0ae9f2560" clas= s=3D"x_OWAAutoLink" data-auth=3D"NotApplicable" data-outlook-id=3D"b4824cb0= -6610-43a4-afcf-bfe69afa0b2c" style=3D"color: blue; margin-top: 0px; margin= -bottom: 0px;"><u>https://github.com/LibinLiu0189/draft-ippm-active-loss-co= nsiderations/blob/main/slides-ippm-active-loss-considerations-00.pdf</u></a= ></span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">If the topic is of interest, I would apprecia= te any comments or feedback. I would also be happy to discuss the work, eit= her in Vienna during IETF 126 or online.</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">Thank you very much.</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">Best,</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;">Libin</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"color: black;"> </span></p> <hr align=3D"center" style=3D"margin-right: 0cm; margin-left: 0cm; width: 9= 8%;"> <div id=3D"x_x_divRplyFwdMsg"> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"font-family: Calibri, sans-serif; font-size: 11pt; color: bl= ack;"><b>From:</b> Libin Liu <</span><span style=3D"font-family: Ca= libri, sans-serif; font-size: 11pt; color: blue;"><a href=3D"mailto:liulb= =3D40zgclab.edu.cn-Tr9gZwTxerDR74oF6e/[email protected]" id=3D"OWA04e1af83-4baa-41a2-b22c-b904f13= 58e27" class=3D"x_OWAAutoLink" data-outlook-id=3D"7d193480-1d86-4d45-bbdf-9= ddd22c8066d" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"><u= >liulb=3D40zgclab.edu.cn-Tr9gZwTxerDR74oF6e/[email protected]</u></a></span><span style=3D"font-f= amily: Calibri, sans-serif; font-size: 11pt; color: black;">><br> <b>Sent:</b> Thursday, July 2, 2026 9:30 AM<br> <b>To:</b> </span><span style=3D"font-family: Calibri, sans-serif; font-siz= e: 11pt; color: blue;"><a href=3D"mailto:[email protected]" id=3D"OWA8f55c01a-f= d1b-8ce3-4ac9-c703bd17da56" class=3D"x_OWAAutoLink" data-outlook-id=3D"21cc= 80fb-0e05-4350-82a3-13a004708071" style=3D"color: blue; margin-top: 0px; ma= rgin-bottom: 0px;"><u>[email protected]</u></a></span><span style=3D"font-famil= y: Calibri, sans-serif; font-size: 11pt; color: black;"> <</span><s= pan style=3D"font-family: Calibri, sans-serif; font-size: 11pt; color: blue= ;"><a href=3D"mailto:[email protected]" id=3D"OWA05966250-2493-4b75-473b-a6dc32= a6cb21" class=3D"x_OWAAutoLink" data-outlook-id=3D"b8b110b9-808d-4a78-8113-= e11cc8c24caf" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"><= u>[email protected]</u></a></span><span style=3D"font-family: Calibri, sans-ser= if; font-size: 11pt; color: black;">>; </span><span style=3D"font-family: Calibri, sans-serif; font-size: 11pt; co= lor: blue;"><a href=3D"mailto:[email protected]" id=3D"OWAc0ed115e-1f0d-65fe-b0= e9-8fc59d41d40c" class=3D"x_OWAAutoLink" data-outlook-id=3D"1d2a003b-c481-4= 20c-82be-bc224ba8f107" style=3D"color: blue; margin-top: 0px; margin-bottom= : 0px;"><u>[email protected]</u></a></span><span style=3D"font-family: Calibri,= sans-serif; font-size: 11pt; color: black;"> <</span><span style= =3D"font-family: Calibri, sans-serif; font-size: 11pt; color: blue;"><a hre= f=3D"mailto:[email protected]" id=3D"OWAa8735372-7042-c56b-9f21-c4e93603f896" c= lass=3D"x_OWAAutoLink" data-outlook-id=3D"f4dc8611-8c56-44a0-b51f-04af8a77c= 698" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"><u>bmwg@ie= tf.org</u></a></span><span style=3D"font-family: Calibri, sans-serif; font-= size: 11pt; color: black;">><br> <b>Subject:</b> [bmwg] New ID: Considerations for Interpreting Packet = Loss Observed by Active Performance Measurements</span></p> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= </p> </div> <p style=3D"margin: 0cm; font-family: Aptos, sans-serif; font-size: 12pt;">= <span style=3D"font-size: 11pt;">Dear All,<br> <br> I would like to draw your attention to a new draft that has recently been s= ubmitted: draft-liu-ippm-active-measurement-loss-considerations-00.<br> <br> This document discusses considerations for interpreting packet loss observe= d by active performance measurements. While measurement protocols and metri= cs accurately report observable outcomes such as packet loss, missing respo= nses, delay, and delay variation, these observations alone often do not reveal the underlying operational ca= use. Similar measurement results may arise from different conditions, inclu= ding congestion, forwarding failures, routing changes, filtering policies, = endpoint behavior, multipath forwarding, or validation-related packet discard. <br> <br> The document proposes a common interpretation framework that distinguishes = measured outcomes from inferred causes. It discusses how different operatio= nal conditions may affect the interpretation of packet loss, delay, and del= ay variation in active performance measurements, including one-way and two-way measurements, OWAMP, TWAMP, ST= AMP, and measurements over ECMP and link aggregation. The document also dis= cusses how additional operational context may assist operators and measurem= ent systems in reasoning about possible explanations for observed measurement results. The draft is available here= : </span> <span style=3D"font-size: 11pt; color: blue;"><a href=3D"https://datatracke= r.ietf.org/doc/draft-liu-ippm-active-loss-considerations/" id=3D"OWA44a6135= 5-0000-1633-e5c5-61c4b7a9694c" class=3D"x_OWAAutoLink" data-auth=3D"NotAppl= icable" data-outlook-id=3D"da9f6cce-5dc5-46ed-ace1-683b91cda7fc" style=3D"c= olor: blue; margin-top: 0px; margin-bottom: 0px;"><u>https://datatracker.ie= tf.org/doc/draft-liu-ippm-active-loss-considerations/</u></a></span><span s= tyle=3D"font-size: 11pt;">. The GitHub repository for the draft is also available here for issues, com= ments, and pull requests: </span><span style=3D"font-size: 11pt; color: blue;"><a href=3D"https://git= hub.com/LibinLiu0189/draft-ippm-active-loss-considerations" id=3D"OWA89b6f7= f7-e9e1-1b3c-0fb5-3e12943cc823" class=3D"x_OWAAutoLink" data-auth=3D"NotApp= licable" data-outlook-id=3D"d4023496-0cf7-48b2-bd6d-38cf30a3a55e" style=3D"= color: blue; margin-top: 0px; margin-bottom: 0px;"><u>https://github.com/Li= binLiu0189/draft-ippm-active-loss-considerations</u></a></span><span style= =3D"font-size: 11pt;">.<br> <br> Comments, suggestions, and discussions would be greatly appreciated. I woul= d also be interested to hear whether similar interpretation challenges have= been encountered in operational deployments or existing measurement system= s, and whether there are additional scenarios that should be considered in the document.<br> <br> Thank you very much.<br> <br> <br> Best,<br> Libin<br> <br> > -----Original Messages-----<br> > From: </span><span style=3D"font-size: 11pt; color: blue;"><a href=3D"= mailto:[email protected]" id=3D"OWA814cf6f8-1dd7-46eb-06a7-f7fdd642a= 5f9" class=3D"x_OWAAutoLink" data-outlook-id=3D"b6b8502c-25fa-4502-9c2e-18b= 7e0fbf16e" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"><u>i= [email protected]</u></a></span><span style=3D"font-size: 11pt;"><br> > Send time:Wednesday, 01/07/2026 17:09:28<br> > To: "Libin Liu" <</span><span style=3D"font-size: 11pt; c= olor: blue;"><a href=3D"mailto:[email protected]" id=3D"OWAcbe391d6-9ae6-= 43d7-8618-565370fafc2e" class=3D"x_OWAAutoLink" data-outlook-id=3D"06b5547d= -6362-4eac-aa52-a580d5fe79fa" style=3D"color: blue; margin-top: 0px; margin= -bottom: 0px;"><u>[email protected]</u></a></span><span style=3D"font-siz= e: 11pt;">><br> > Subject: New Version Notification for draft-liu-ippm-active-loss-consi= derations-00.txt<br> ><br> > A new version of Internet-Draft<br> > draft-liu-ippm-active-loss-considerations-00.txt has been successfully= <br> > submitted by Libin Liu and posted to the<br> > IETF repository.<br> ><br> > Name: draft-liu-ippm-active-loss-consideration= s<br> > Revision: 00<br> > Title: Considerations for Interpreting Packet Loss O= bserved by Active Performance Measurements<br> > Date: 2026-07-01<br> > Group: Individual Submission<br> > Pages: 30<br> > URL: </span><span style=3D"font-size: 11= pt; color: blue;"><a href=3D"https://www.ietf.org/archive/id/draft-liu-ippm= -active-loss-considerations-00.txt" id=3D"OWAc273ec46-6863-5d30-bc47-3722f2= c6bd4a" class=3D"x_OWAAutoLink" data-auth=3D"NotApplicable" data-outlook-id= =3D"1916b421-1b75-4964-9969-450a73d18354" style=3D"color: blue; margin-top:= 0px; margin-bottom: 0px;"><u>https://www.ietf.org/archive/id/draft-liu-ipp= m-active-loss-considerations-00.txt</u></a></span><span style=3D"font-size:= 11pt;"><br> > Status: </span><span style=3D"font-size: 11pt; color: blue= ;"><a href=3D"https://datatracker.ietf.org/doc/draft-liu-ippm-active-loss-c= onsiderations/" id=3D"OWAe0b7d623-af12-f805-ff3e-df34ed228a31" class=3D"x_O= WAAutoLink" data-auth=3D"NotApplicable" data-outlook-id=3D"00aa3351-4f12-4b= a3-9593-c54a660ecf75" style=3D"color: blue; margin-top: 0px; margin-bottom:= 0px;"><u>https://datatracker.ietf.org/doc/draft-liu-ippm-active-loss-consi= derations/</u></a></span><span style=3D"font-size: 11pt;"><br> > HTML: </span><span style=3D"font-size: 11pt; c= olor: blue;"><a href=3D"https://www.ietf.org/archive/id/draft-liu-ippm-acti= ve-loss-considerations-00.html" id=3D"OWA5f6e61dc-d36a-d561-5bb2-4054005511= 6b" class=3D"x_OWAAutoLink" data-auth=3D"NotApplicable" data-outlook-id=3D"= 31066c4a-c31e-4f63-ad05-42d28c78ee91" style=3D"color: blue; margin-top: 0px= ; margin-bottom: 0px;"><u>https://www.ietf.org/archive/id/draft-liu-ippm-ac= tive-loss-considerations-00.html</u></a></span><span style=3D"font-size: 11= pt;"><br> > HTMLized: </span><span style=3D"font-size: 11pt; color: blue;"><a href= =3D"https://datatracker.ietf.org/doc/html/draft-liu-ippm-active-loss-consid= erations" id=3D"OWAead395c8-ed6f-c335-1cfa-3a5eb0ee1f81" class=3D"x_OWAAuto= Link" data-auth=3D"NotApplicable" data-outlook-id=3D"41db0261-9048-493a-8ff= 9-01c4a491a763" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"= ><u>https://datatracker.ietf.org/doc/html/draft-liu-ippm-active-loss-consid= erations</u></a></span><span style=3D"font-size: 11pt;"><br> ><br> ><br> > Abstract:<br> ><br> > Active performance measurement protocols and metrics= are commonly<br> > used to measure packet loss, delay, delay variation,= reachability,<br> > and path behavior. When an active measurement = packet is not<br> > received, a response is missing, or a measurement ex= change times out,<br> > the measurement result identifies the observable out= come but often<br> > does not identify the underlying cause.<br> ><br> > Loss observed by active performance measurements can= be associated<br> > with congestion, queue discard, link or forwarding f= ailures, routing<br> > changes, endpoint or reflector behavior, administrat= ive filtering,<br> > policing, multipath effects, or validation-related p= acket discard<br> > such as Source Address Validation (SAV). Diffe= rent operational<br> > conditions can produce similar measurement observati= ons, but they may<br> > have different meanings and require different troubl= eshooting<br> > actions.<br> ><br> > This document discusses considerations for interpret= ing packet loss<br> > observed by active performance measurements. I= t provides a common<br> > set of considerations for separating measured outcom= es from inferred<br> > causes, describes operational conditions that can le= ad to observed<br> > loss, discusses implications for one-way and two-way= measurements,<br> > delay and delay variation interpretation, OWAMP, TWA= MP, STAMP, and<br> > measurements over ECMP and link aggregation. I= t also discusses how<br> > some considerations may apply to hybrid and passive = performance<br> > measurements and identifies sources of operational c= ontext that can<br> > help operators and measurement systems reason about = possible<br> > explanations.<br> ><br> ><br> ><br> > The IETF Secretariat<br> ><br> _______________________________________________<br> bmwg mailing list -- </span><span style=3D"font-size: 11pt; color: blue;"><= a href=3D"mailto:[email protected]" id=3D"OWA737ad100-2fe8-78fb-01d5-0055842e52= 42" class=3D"x_OWAAutoLink" data-outlook-id=3D"b8d06556-deca-4b09-ad62-5d83= bfc0b006" style=3D"color: blue; margin-top: 0px; margin-bottom: 0px;"><u>bm= [email protected]</u></a></span><span style=3D"font-size: 11pt;"><br> To unsubscribe send an email to </span><span style=3D"font-size: 11pt; colo= r: blue;"><a href=3D"mailto:[email protected]" id=3D"OWA401d3789-2224-a24= d-91d7-874a271e7bcf" class=3D"x_OWAAutoLink" data-outlook-id=3D"8ba4346b-a5= e3-48c2-b6c7-7891de377cbc" style=3D"color: blue; margin-top: 0px; margin-bo= ttom: 0px;"><u>[email protected]</u></a></span></p> </div> </body> </html> --_000_TY4PR01MB12668D750000AC86698CB5E1EE2CF2TY4PR01MB12668jp_-- --===============8354606633942886223== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KaXBwbSBtYWls aW5nIGxpc3QgLS0gaXBwbUBpZXRmLm9yZwpUbyB1bnN1YnNjcmliZSBzZW5kIGFuIGVtYWlsIHRv IGlwcG0tbGVhdmVAaWV0Zi5vcmcK --===============8354606633942886223==--