{"id":6154,"date":"2021-01-08T12:59:08","date_gmt":"2021-01-08T10:59:08","guid":{"rendered":"https:\/\/tekmart.co.za\/t-blog\/?p=6154"},"modified":"2021-01-08T12:59:09","modified_gmt":"2021-01-08T10:59:09","slug":"latency-a-tech-definition","status":"publish","type":"post","link":"https:\/\/tekmart.co.za\/t-blog\/latency-a-tech-definition\/","title":{"rendered":"latency-a tech definition"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading Time-approximately:<\/span> <span class=\"rt-time\"> 4<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span>\n<h2 class=\"wp-block-heading\"><strong>Latency is a synonym for delay. In\u00a0telecommunications, low latency is associated with a positive user experience (UX) while high latency is associated with poor UX.<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/cdn.ttgtmedia.com\/rms\/onlineImages\/rouse_margaret.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p>Posted by:\u00a0<a href=\"https:\/\/www.techtarget.com\/contributor\/Margaret-Rouse\">Margaret Rouse<\/a><\/p>\n\n\n\n<p>WhatIs.com<\/p>\n\n\n\n<p>Contributor(s):\u00a0<a href=\"https:\/\/www.techtarget.com\/contributor\/Alexander-S-Gillis\">Alexander Gillis<\/a>, Matthew Haughn and Ed Blair<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>In computer networking, latency is an expression of how much time it takes for a data\u00a0packet\u00a0to travel from one designated point to another. Ideally, latency will be as close to zero as possible. Network latency can be measured by determining the <strong>round-trip time (RTT<\/strong>) for a packet of data to travel to a destination and back again.<\/p><\/blockquote>\n\n\n\n<p>High network latency can dramatically increase webpage load times, interrupt video and audio streams, and render an application unusable. Depending on the application, even a relatively small increase in&nbsp;latency&nbsp;can ruin UX.<\/p>\n\n\n\n<p>One of the major reasons for poor latency is geography. Highly distributed Internet Protocol (IP) networks traverse vast distances, adding transmission time that can derail an application. In any situation where the latency between sensing and responding needs to be extremely low &#8212; for example, certain actions in autonomous driving &#8212; it makes sense to put the computer that&#8217;s processing the data as close to the source of the data as possible, a concept known as\u00a0<em>edge computing<\/em>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Causes of latency in telecom<\/strong><\/h3>\n\n\n\n<p>Latency can be caused by many things, including the following:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Transmission media.<\/strong>\u00a0Latency can be affected by the type of media being used to transmit data, voice and video. For example, packets traveling over a\u00a0<a href=\"https:\/\/searchnetworking.techtarget.com\/definition\/T1-T-1\">T1<\/a>\u00a0line can be expected to experience lower latency than packets traveling over a\u00a0Cat5\u00a0cable.<\/li><li><strong>Packet size.<\/strong>\u00a0A large packet will take longer to send round trip than a small one.<\/li><li><strong>Packet loss\u00a0and\u00a0jitter.<\/strong>\u00a0Latency can also be introduced by a high percentage of packets that fail to make their destination or too much variation in the time it takes for some packets to travel from one system to another.<\/li><li><strong>Signal strength.<\/strong>\u00a0If the signal is weak and has to be boosted by a\u00a0repeater, this can introduce latency.<\/li><li><strong>Propagation delays.\u00a0<\/strong>If each\u00a0gateway\u00a0node\u00a0has to take time to examine and possibly change the header in a packet &#8212; for example, changing the hop count in the\u00a0time-to-live\u00a0(TTL) field &#8212; latency will be higher.<\/li><li><strong>Other computer and storage delays.<\/strong>\u00a0If a packet is subject to\u00a0storage and hard disk access delays\u00a0at an intermediate device, such as a\u00a0switch, latency is likely to be higher.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Types of latency<\/strong><\/h3>\n\n\n\n<p><strong>Interrupt latency<\/strong>\u00a0is the length of time that it takes for a computer to act on a signal that tells the host\u00a0operating system\u00a0(OS) to stop until it can decide what it should do in response to an event.<\/p>\n\n\n\n<p><strong>fiber optic&nbsp;<\/strong><strong>latency<\/strong>&nbsp;is how long it takes for light to travel a specified distance through a fiber optic cable. For every kilometer (km) covered, a latency of 3.33 microseconds (\u03bcs) naturally occurs, according to the speed of light. In reality, however, the per-kilometer latency of fiber optic cables is about 4.9 \u03bcs &#8212; this is because light travels slower in a cable. Bends or other imperfections in the cable could make the latency higher.<\/p>\n\n\n\n<p><strong>Internet latency<\/strong>\u00a0times are dependent upon distance. The longer a packet has to travel across a global wide area network (WAN), the higher the latency.<\/p>\n\n\n\n<p><strong>WAN latency<\/strong>\u00a0can be an important factor in determining internet latency. A WAN that is busy directing other traffic will produce a delay, whether the resource is being requested from a server on the local area network\u00a0(LAN), another computer on that network or elsewhere on the internet.<\/p>\n\n\n\n<p><strong>Audio latency<\/strong>\u00a0is the delay between sound being created and heard. In sound created in the physical world, this delay is determined by the\u00a0speed of sound, which varies slightly depending on the medium the\u00a0sound wave\u00a0travels through. Sound travels faster in denser mediums: It travels faster through solids, less quickly through liquids and slowest through air. In audio, the acceptable midrange of latency is around 8 to 12 \u03bcs. Latencies of 30\u00a0milliseconds\u00a0(ms) are generally noticed by the listener.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"Measuring audio latency on iOS\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/C8StPwiHTCc?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption><em><strong>Watch the video demonstration above, and learn how to measure audio latency on iOS devices<\/strong><\/em><\/figcaption><\/figure>\n\n\n\n<p><em>Watch the video demonstration below, and learn how to measure audio latency on iOS devices.<\/em>https:\/\/www.youtube.com\/embed\/C8StPwiHTCc<\/p>\n\n\n\n<p><strong>Operational latency<\/strong>\u00a0can be defined as the sum time of operations if they are performed in a linear\u00a0workflow. In parallel workflows, the latency is determined by the slowest operation performed by a single task worker.<\/p>\n\n\n\n<p><strong>Mechanical latency<\/strong>\u00a0is the delay from input into a mechanical system or device to the desired output. This delay is determined by Newtonian physics-based limits of the mechanism (excepting\u00a0quantum\u00a0mechanics).<\/p>\n\n\n\n<p><strong>Computer and OS latency<\/strong>\u00a0is the combined delay between an input or command and the desired output. Contributors to increased computer latency include insufficient data\u00a0buffers\u00a0and mismatches in data speed between the microprocessor and input\/output (I\/O) devices.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Latency testing and measurement<\/strong><\/h3>\n\n\n\n<p>Latency testing can vary from application to application. In some applications, measuring latency requires special and complex equipment or knowledge of special computer commands and programs; in other cases, latency can be measured with a stopwatch. Network managers have&nbsp;a number of tools&nbsp;to choose from to do this, including Traceroute, My traceroute (MTR) and Ping.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>Ping\u00a0commands are used to determine if a host computer the user is trying to reach is operating. To evaluate latency, a network administrator sends an Internet Control Message Protocol (ICMP) echo request to a specified interface on the network and waits for a reply.<\/p><\/blockquote>\n\n\n\n<p>Information about latency can also be gathered by using a\u00a0traceroute\u00a0command. Traceroute visualizes the path that packets take across an IP network, recording latency between each host on the route. MTR blends elements of both Ping and Traceroute to track both the delay between devices on the path and the total transit time.<\/p>\n\n\n\n<p>To evaluate mechanical latency, high-speed cameras can be used to capture the minute differences in response times from input to mechanical action.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Reducing latency<\/strong><\/h3>\n\n\n\n<p>Latency can be reduced by tuning, tweaking and upgrading computer hardware, software and mechanical systems. Within a computer, latency can be removed or hidden by such techniques as prefetching &#8212; anticipating the need for data input requests &#8212; and&nbsp;Multithreading&nbsp;or by using parallelism across multiple execution threads.<\/p>\n\n\n\n<p>Other steps to reduce latency and increase performance include uninstalling unnecessary programs, optimizing networking and software configurations, and upgrading or\u00a0overclocking\u00a0hardware.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Latency vs. throughput<\/strong><\/h3>\n\n\n\n<p>Both\u00a0throughput\u00a0and latency are commonly used to measure network performance and improve load times.<\/p>\n\n\n\n<p>Latency can be thought of as the time it takes to perform an action, while throughput can be thought of as the number of actions that can be executed in one unit of time. In other words, latency measures how quickly data takes to be transferred, while throughput is how much data can be sent.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p><a href=\"https:\/\/www.techtarget.com\/contributor\/Margaret-Rouse\"><\/a><a href=\"https:\/\/www.techtarget.com\/contributor\/Margaret-Rouse\">Margaret Rouse<\/a>\u00a0asks:<\/p><p>What&#8217;s an acceptable latency for enterprise IT connectivity between major cities?<\/p><\/blockquote>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><a href=\"https:\/\/whatis.techtarget.com\/definition\/latency?_ga=2.238100422.737222100.1610003465-706917095.1609594483#commenting\"><strong>Join the Discussion<\/strong><\/a><\/h2>\n\n\n\n<p>Bandwidth\u00a0is another concept that is often associated with latency. Bandwidth describes the maximum capacity of a network\/internet connection. The less bandwidth a network has, the more latency.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>To understand bandwidth&#8217;s relationship with latency, picture bandwidth as a pipe and throughput as how much water a pipe can carry over a specified time. Latency becomes the time it takes for the water to reach its destination. The smaller the pipe, the more time it takes for the water to reach its destination. With the same notion, the bigger the pipe, the faster the water can reach its destination. Bandwidth and latency have a cause-and-effect relationship in this way.<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p><span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading Time-approximately:<\/span> <span class=\"rt-time\"> 4<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span>Latency is a synonym for delay. In\u00a0telecommunications, low latency is associated with a positive user experience (UX) while high latency is associated with poor UX. Posted by:\u00a0Margaret Rouse WhatIs.com Contributor(s):\u00a0Alexander Gillis, Matthew Haughn and Ed Blair In computer networking, latency is an expression of how much time it takes for a data\u00a0packet\u00a0to travel from one designated point to another. Ideally,<\/p>\n<p><a class=\"more-link\" href=\"https:\/\/tekmart.co.za\/t-blog\/latency-a-tech-definition\/\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,5,30,3,51,9],"tags":[],"class_list":["post-6154","post","type-post","status-publish","format-standard","hentry","category-datacenter-news","category-engage-the-experts","category-expert-advise-and-opinion","category-industry-news-and-expert-advise","category-tech-acronyms-and-initialisms","category-tech-definitions"],"_links":{"self":[{"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/posts\/6154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/comments?post=6154"}],"version-history":[{"count":1,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/posts\/6154\/revisions"}],"predecessor-version":[{"id":6155,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/posts\/6154\/revisions\/6155"}],"wp:attachment":[{"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/media?parent=6154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/categories?post=6154"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tekmart.co.za\/t-blog\/wp-json\/wp\/v2\/tags?post=6154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}