From 0de316f8022c421fca6099c2d5b70ecaf92264c8 Mon Sep 17 00:00:00 2001 From: Omer Shapira Date: Mon, 6 Dec 2021 10:16:47 -0800 Subject: [PATCH] Working on adding the notes and summarizing the metrics discussions --- draft-iab-mnqeu-report.md | 47 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/draft-iab-mnqeu-report.md b/draft-iab-mnqeu-report.md index cbc7920..d644021 100644 --- a/draft-iab-mnqeu-report.md +++ b/draft-iab-mnqeu-report.md @@ -275,6 +275,9 @@ informative: - ins: S. Cheshire seriesinfo: https://www.iab.org/wp-content/IAB-uploads/2021/09/Internet-Score-2.pdf + ping: + title: "PING(8)" + --- abstract The Measuring Network Quality for End-Users workshop was held @@ -433,6 +436,50 @@ of the Internet. The need for improvements to latency and its measurements was heavily discussed, especially for certain classes of users such as live, collaborative content and gaming. +### Latency considerations + +End-to-end latency is the time it takes for a particular segment to traverse +the entire network path from the user to their destionation. The end-to-end +latency comprises several components: + +1. The propagation delay, which reflects the path distance and the individual + link technologies (e.g. fibre vs satellite). The propagation doesn't depend + on the utilization of the network, to the extent that the network path + remains constant. +2. The buffering delay, which reflects the time segments spend in the memory of + the network equipment that connect the individual network links, as well as + in the memory of the transmitting endpoint. The buffering delay depends on + the network utilization, as well as on the algorithms that govern the queued segments. +3. The transport protocol delays, which reflects the time spent in + retransmission and reassembly, as well as the time spent when the transport + is "head-of-line blocked." +4. Some of the workshop sumbissions have explicitly called out the application + delay, which reflects the inefficiencies in the application layer. + +### Idle latency vs. working latency. + +Tradionally, end-to-end latency is measured with tools such as {{ping}}, as +well as with services such as {{speedtest}} or {{ookla}}. +Such measurements are typically performed when the network is idle, and as a +result, such measurements reflect mostly the propagation delay. + +A different way to measure end-to-end latency is to perform the test when the +network is not idle, but in its typical working conditions. + +The workshop participants used the term "Idle latency" when referring to the +subject of the former measurement methods, and "Working latency" when referring +to the latter. + +### Metrics - conclusions + +Through the course of the workshop, the following statements have emerged: + +1. There's a dramatic difference between the idle latency and the working + latency measurements. +2. The variance in idle latency is not high, while the working latency varies + wildly. +3. Most of the tools to measure end-to-end latency focus on the idle latency. + ## Cross-layer considerations In the Cross-layer section participants presented material and discussed