CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>List of ITU-T V-series recommendations - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"345150c0-9b8a-4ff3-bc86-f408c249d9ef","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"List_of_ITU-T_V-series_recommendations","wgTitle":"List of ITU-T V-series recommendations","wgCurRevisionId":1265227066,"wgRevisionId":1265227066,"wgArticleId":5419226,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Articles with short description","Short description is different from Wikidata","Modems","ITU-T recommendations","Lists of standards"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"List_of_ITU-T_V-series_recommendations","wgRelevantArticleId":5419226,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[], "wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":20000,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q2624253","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={ "ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming", "ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.16"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="List of ITU-T V-series recommendations - Wikipedia"> <meta property="og:type" content="website"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/List_of_ITU-T_V-series_recommendations"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/List_of_ITU-T_V-series_recommendations"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-List_of_ITU-T_V-series_recommendations rootpage-List_of_ITU-T_V-series_recommendations skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" title="Main menu" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li><li id="n-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages"><span>Special pages</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=List+of+ITU-T+V-series+recommendations" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=List+of+ITU-T+V-series+recommendations" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=List+of+ITU-T+V-series+recommendations" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=List+of+ITU-T+V-series+recommendations" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-General_standards" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#General_standards"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>General standards</span> </div> </a> <ul id="toc-General_standards-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Interfaces_and_voiceband_modems" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interfaces_and_voiceband_modems"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Interfaces and voiceband modems</span> </div> </a> <button aria-controls="toc-Interfaces_and_voiceband_modems-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Interfaces and voiceband modems subsection</span> </button> <ul id="toc-Interfaces_and_voiceband_modems-sublist" class="vector-toc-list"> <li id="toc-Ad_hoc_standards" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Ad_hoc_standards"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Ad hoc standards</span> </div> </a> <ul id="toc-Ad_hoc_standards-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Wideband_modems" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Wideband_modems"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Wideband modems</span> </div> </a> <ul id="toc-Wideband_modems-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Error_control_and_data_compression" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Error_control_and_data_compression"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Error control and data compression</span> </div> </a> <ul id="toc-Error_control_and_data_compression-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Simultaneous_transmission_of_data_and_other_signals" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Simultaneous_transmission_of_data_and_other_signals"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Simultaneous transmission of data and other signals</span> </div> </a> <ul id="toc-Simultaneous_transmission_of_data_and_other_signals-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Interworking_with_other_networks" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interworking_with_other_networks"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Interworking with other networks</span> </div> </a> <ul id="toc-Interworking_with_other_networks-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Interface_layer_specifications_for_data_communication" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interface_layer_specifications_for_data_communication"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Interface layer specifications for data communication</span> </div> </a> <ul id="toc-Interface_layer_specifications_for_data_communication-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Control_procedures" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Control_procedures"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Control procedures</span> </div> </a> <ul id="toc-Control_procedures-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Digital_circuit_modems" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Digital_circuit_modems"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>Digital circuit modems</span> </div> </a> <ul id="toc-Digital_circuit_modems-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">12</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">List of ITU-T V-series recommendations</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 3 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-3" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">3 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Llista_de_recomanacions_de_la_s%C3%A8rie_V_de_l%27ITU-T" title="Llista de recomanacions de la sèrie V de l'ITU-T – Catalan" lang="ca" hreflang="ca" data-title="Llista de recomanacions de la sèrie V de l'ITU-T" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Anexo:Recomendaciones_de_la_serie_V_de_UIT-T" title="Anexo:Recomendaciones de la serie V de UIT-T – Spanish" lang="es" hreflang="es" data-title="Anexo:Recomendaciones de la serie V de UIT-T" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9F%D1%80%D0%BE%D1%82%D0%BE%D0%BA%D0%BE%D0%BB%D1%8B_%D0%BC%D0%BE%D0%B4%D0%B5%D0%BC%D0%BD%D0%BE%D0%B9_%D1%81%D0%B2%D1%8F%D0%B7%D0%B8" title="Протоколы модемной связи – Russian" lang="ru" hreflang="ru" data-title="Протоколы модемной связи" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q2624253#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/List_of_ITU-T_V-series_recommendations" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:List_of_ITU-T_V-series_recommendations" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/List_of_ITU-T_V-series_recommendations"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/List_of_ITU-T_V-series_recommendations"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/List_of_ITU-T_V-series_recommendations" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/List_of_ITU-T_V-series_recommendations" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&oldid=1265227066" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=List_of_ITU-T_V-series_recommendations&id=1265227066&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FList_of_ITU-T_V-series_recommendations"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FList_of_ITU-T_V-series_recommendations"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=List_of_ITU-T_V-series_recommendations&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Modem_spectrums" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q2624253" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><p> The <b>ITU-T V-Series Recommendations</b> on <b>Data communication over the telephone network</b> specify the protocols that govern approved <a href="/wiki/Modem" title="Modem">modem</a> communication standards and interfaces.<sup id="cite_ref-Vseries_1-0" class="reference"><a href="#cite_note-Vseries-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p><p><b>Note:</b> the <i><a href="https://en.wiktionary.org/wiki/bis#Latin" class="extiw" title="wikt:bis">bis</a></i> and <i><a href="https://en.wiktionary.org/wiki/ter#Latin" class="extiw" title="wikt:ter">ter</a></i> suffixes are <a href="/wiki/ITU-T" title="ITU-T">ITU-T</a> standard designators of successive iterations of a standard (<i>bis</i> and <i>ter</i> are the <a href="/wiki/Latin" title="Latin">Latin</a> words for "twice" and "thrice"). </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="General_standards">General standards</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=1" title="Edit section: General standards"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.1–V.9</i> </p> <ul><li><span class="anchor" id="V.1"></span> <b>V.1</b> is an ITU-T recommendation, entitled <i>Equivalence between binary notation symbols and the significant conditions of a two-condition code.</i></li> <li><span class="anchor" id="V.2"></span> <b>V.2</b> is an ITU-T recommendation, approved in November 1988, titled <i>Power levels for data transmission over telephone lines.</i></li> <li><span class="anchor" id="V.4"></span> <b>V.4</b> is an ITU-T recommendation, approved in November 1988, titled <i>General structure of signals of International Alphabet No. 5 code for character oriented data transmission over public telephone networks.</i></li> <li><span class="anchor" id="V.5"></span> <b>V.5</b> was an ITU-T recommendation, approved in November 1988, titled <i>Standardization of data signalling rates for synchronous data transmission in the general switched telephone network.</i> It has been withdrawn since.</li> <li><span class="anchor" id="V.6"></span> <b>V.6</b> was an ITU-T recommendation, approved in November 1988, titled <i>Standardization of data signalling rates for synchronous data transmission on leased telephone-type circuits.</i> It has been withdrawn since.</li> <li><span class="anchor" id="V.7"></span> <b>V.7</b> is an ITU-T recommendation, approved in November 1988, titled <i>Definitions of terms concerning data communication over the telephone network.</i></li> <li><span class="anchor" id="V.8"></span> <b>V.8</b> is an ITU-T recommendation, first approved in September 1994, titled <i>Procedures for starting sessions of data transmission over the public switched telephone network.</i> It has been superseded three times. The current version was approved in November 2000. <ul><li><b>V.8bis</b> is an ITU-T recommendation, first approved in August 1996, titled <i>Procedures for the identification and selection of common modes of operation between data circuit-terminating equipments (DCEs) and between data terminal equipments (DTEs) over the public switched telephone network and on leased point-to-point telephone-type circuits.</i> It has been superseded twice. The current version was approved in November 2000.</li></ul></li></ul> <div class="mw-heading mw-heading2"><h2 id="Interfaces_and_voiceband_modems">Interfaces and voiceband modems</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=2" title="Edit section: Interfaces and voiceband modems"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.10–V.34</i> </p> <ul><li><b><a href="/wiki/ITU-T_V.10" class="mw-redirect" title="ITU-T V.10">V.10</a></b> is an ITU-T recommendation, first agreed in 1976, for unbalanced electrical circuits for data communication at up to 100 <a href="/wiki/Kilobit" class="mw-redirect" title="Kilobit">kbit</a>/s. It can interwork with V.28, provided it is not exposed to signals greater than 12 volts. Used with the 37-pin ISO 4902 connector, it is compatible with EIA <a href="/wiki/RS-423" title="RS-423">RS-423</a>.</li> <li><b><a href="/wiki/ITU-T_V.11" class="mw-redirect" title="ITU-T V.11">V.11</a></b> is an ITU-T recommendation, first agreed in 1976, for balanced electrical circuits for data communication at up to 10 <a href="/wiki/Megabit" class="mw-redirect" title="Megabit">Mbit</a>/s. Used with the 37-pin ISO 4902 connector ("<a href="/wiki/D-subminiature" title="D-subminiature">DC-37</a>"), it is compatible with <a href="/wiki/EIA-422" class="mw-redirect" title="EIA-422">EIA-422</a>. The 15-pin ISO 4903 connector ("<a href="/wiki/D-subminiature" title="D-subminiature">DA-15</a>") is recommended for data network interface.</li> <li><span class="anchor" id="V.17"></span> <b>V.17</b> is an ITU-T recommendation for a <a href="/wiki/Fax" title="Fax">fax</a> modem using <a href="/wiki/Trellis_modulation" class="mw-redirect" title="Trellis modulation">TCM</a> <a href="/wiki/Modulation" title="Modulation">modulation</a> at 12 and 14.4 <a href="/wiki/Kbit/s" class="mw-redirect" title="Kbit/s">kbit/s</a>.</li> <li><b><a href="/wiki/ITU-T_V.18" class="mw-redirect" title="ITU-T V.18">V.18</a></b> is an ITU-T recommendation for operation and interworking of text telephone devices</li> <li><span class="anchor" id="V.21"></span> <b>V.21</b> is an ITU-T recommendation for <a href="/wiki/Duplex_(telecommunications)" title="Duplex (telecommunications)">full-duplex</a> communication between two <a href="/wiki/Analog_signal" title="Analog signal">analogue</a> dial-up <a href="/wiki/Modem" title="Modem">modems</a> using <a href="/wiki/Audio_frequency-shift_keying" class="mw-redirect" title="Audio frequency-shift keying">audio frequency-shift keying</a> <a href="/wiki/Modulation" title="Modulation">modulation</a> at 300 <a href="/wiki/Baud" title="Baud">baud</a> to carry <a href="/wiki/Digital_data" title="Digital data">digital</a> <a href="/wiki/Data" title="Data">data</a> at 300 <a href="/wiki/Bit/s" class="mw-redirect" title="Bit/s">bit/s</a>. It is a variant of the original <a href="/wiki/Bell_103" title="Bell 103">Bell 103</a> modulation format.</li> <li><span class="anchor" id="V.22"></span> <b>V.22</b> is an ITU-T recommendation for <a href="/wiki/Duplex_(telecommunications)" title="Duplex (telecommunications)">full-duplex</a> communication between two <a href="/wiki/Analog_signal" title="Analog signal">analogue</a> dial-up <a href="/wiki/Modem" title="Modem">modems</a> using <a href="/wiki/Phase-shift_keying" title="Phase-shift keying">PSK</a> <a href="/wiki/Modulation" title="Modulation">modulation</a> at 600 <a href="/wiki/Baud" title="Baud">baud</a> to carry data at 1200 or 600 <a href="/wiki/Bit/s" class="mw-redirect" title="Bit/s">bit/s</a>. It is a variant of the <a href="/wiki/Bell_212A" title="Bell 212A">Bell 212A</a> modulation format. <ul><li><b>V.22bis</b> is an ITU-T recommendation extending V.22 with a faster rate using <a href="/wiki/Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">QAM</a> at 600 <a href="/wiki/Baud" title="Baud">baud</a> to carry <a href="/wiki/Digital_data" title="Digital data">digital</a> <a href="/wiki/Data" title="Data">data</a> at 2400 or 1200 <a href="/wiki/Bit/s" class="mw-redirect" title="Bit/s">bit/s</a>. The 1200 bit/s mode is compatible with V.22.</li></ul></li> <li><b><a href="/wiki/ITU-T_V.23" title="ITU-T V.23">V.23</a></b> is an ITU-T recommendation for <a href="/wiki/Duplex_(telecommunications)" title="Duplex (telecommunications)">half-duplex</a> communication between two <a href="/wiki/Analog_signal" title="Analog signal">analogue</a> dial-up <a href="/wiki/Modem" title="Modem">modems</a> using <a href="/wiki/Frequency-shift_keying" title="Frequency-shift keying">FSK</a> <a href="/wiki/Modulation" title="Modulation">modulation</a> at up to 600 or 1200 <a href="/wiki/Baud" title="Baud">baud</a> to carry <a href="/wiki/Digital_data" title="Digital data">digital</a> <a href="/wiki/Data" title="Data">data</a> at up to 600 or 1200 <a href="/wiki/Bit/s" class="mw-redirect" title="Bit/s">bit/s</a> respectively. An optional 75 baud reverse channel carries 75 <a href="/wiki/Bit" title="Bit">bit</a>/s.</li> <li><b><a href="/wiki/ITU-T_V.24" class="mw-redirect" title="ITU-T V.24">V.24</a></b> is referenced as <a href="/wiki/RS-232" title="RS-232">RS-232</a> which also includes V.28.</li> <li><b>V.25ter</b> see <a href="#V.250">V.250</a></li> <li><span class="anchor" id="V.27ter"></span> <b>V.27ter</b> is an ITU-T recommendation for a <a href="/wiki/Half-duplex" class="mw-redirect" title="Half-duplex">half-duplex</a> <a href="/wiki/Modem" title="Modem">modem</a>, allowing 2400 and 4800 bit/s (<a href="/wiki/Phase-shift_keying" title="Phase-shift keying">PSK</a> modulation).</li> <li><span class="anchor" id="V.28"></span> <b>V.28</b> is an ITU-T recommendation defining the electrical characteristics for unbalanced double-current interchange circuits.</li> <li><span class="anchor" id="V.29"></span> <b>V.29</b> is an ITU-T recommendation for a <a href="/wiki/Modem" title="Modem">modem</a>, allowing 4.8 kbit/s, 7.2 kbit/s and 9.6 kbit/s transfer modes (<a href="/wiki/Phase-shift_keying" title="Phase-shift keying">PSK</a> and <a href="/wiki/QAM" class="mw-redirect" title="QAM">QAM</a> modulations).</li> <li><span class="anchor" id="V.32"></span> <b>V.32 (11/88)</b> is an ITU-T recommendation for a <a href="/wiki/Modem" title="Modem">modem</a> operating as <a href="/wiki/Full-duplex" class="mw-redirect" title="Full-duplex">full-duplex</a> on a 4-wire circuit, or <a href="/wiki/Half-duplex" class="mw-redirect" title="Half-duplex">half-duplex</a> on a two-wire circuit, allowing bidirectional data transfer at either 9.6 kbit/s or 4.8 kbit/s at a <a href="/wiki/Symbol_rate" title="Symbol rate">symbol rate</a> of 2,400 <a href="/wiki/Baud" title="Baud">baud</a> instead of the 600 <a href="/wiki/Baud" title="Baud">baud</a> of the V.22 standards.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> <ul><li><b>V.32bis (02/91)</b> is an ITU-T recommendation for a <a href="/wiki/Modem" title="Modem">modem</a>, allowing up to 14.4 kbit/s bidirectional data transfer. Other additional defined data transfer rates are 12.0 kbit/s, 9.6 kbit/s, 7.2 kbit/s, and 4.8 kbit/s.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The standard was extended by several modem manufacturers to allow bidirectional data transfer rates of 19.2 kbit/s, but never ratified as a V.32<i>ter</i> standard. These non-ITU-T standard modems were often referred to as "<a href="#V.32terbo">V.32terbo</a>" modems.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup></li></ul></li> <li><span class="anchor" id="V.33"></span> <b>V.33</b> is an ITU-T recommendation for a <a href="/wiki/Modem" title="Modem">modem</a> operating as <a href="/wiki/Full-duplex" class="mw-redirect" title="Full-duplex">full-duplex</a> on a 4-wire point-to-point leased line allowing bidirectional data transfer at either 14.4 kbit/s.</li> <li><span class="anchor" id="V.34"></span> <b>V.34 (09/94)</b> is an ITU-T recommendation (superseded) for a <a href="/wiki/Modem" title="Modem">modem</a>, allowing up to 28.8 kbit/s bidirectional data transfer using <a href="/wiki/Trellis_modulation" class="mw-redirect" title="Trellis modulation">TCM</a> <a href="/wiki/Modulation" title="Modulation">modulation</a>. Other additional defined data transfer rates are 24.0 kbit/s and 19.2 kbit/s as well as all the permitted V.32 and V.32bis rates. Additionally, V.34 modems employ shell mapping as <a href="/wiki/Shaping_codes" title="Shaping codes">shaping code</a> to reduce the transmit power.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> <ul><li><b>V.34 (10/96)</b> is an updated ITU-T recommendation for a modem, building on the V.34 standard but allowing up to 33.6 kbit/s bidirectional data transfer. Other additional defined data transfer rates are 31.2 kbit/s, as well as all the permitted V.34 rates. Modems implementing this standard were often marketed under the moniker <b>V.34+</b>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup></li> <li><b>V.34 (02/98)</b> commonly rendered as V.34bis, is a further update to V.34 which corrected some errata in the original 1996 document.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup></li></ul></li></ul> <div class="mw-heading mw-heading3"><h3 id="Ad_hoc_standards">Ad hoc standards</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=3" title="Edit section: Ad hoc standards"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In order to gain <a href="/wiki/First-mover_advantage" title="First-mover advantage">first-mover advantage</a>, many modem companies introduced models based on upcoming V-series standards before they reached final ratification. In other cases, companies introduced non-standard systems but gave them ITU-like names. </p> <ul><li><span class="anchor" id="V.32terbo"></span> <b>V.32terbo</b>, or <b>V.32ter</b> for short, was a 19.2 kbit/s standard introduced by <a href="/wiki/AT%26T_Paradyne" class="mw-redirect" title="AT&T Paradyne">AT&T Paradyne</a>. It was based on V.32bis and did little other than increase the data rate. V.32ter is compatible with V.32bis at speeds of 14.4 kbit/s and lower, but it is not compatible with V.34 at 19.2.</li> <li><span class="anchor" id="V.FC"></span> <b>V.FC</b>, short for <b>V.Fast Class</b> and sometimes referred to as <b>V.FAST</b>, was developed by <a href="/wiki/Hayes_Microcomputer_Products" title="Hayes Microcomputer Products">Hayes</a> and <a href="/wiki/Conexant" title="Conexant">Rockwell</a> to introduce a 28.8 kbit/s standard while the V.34 efforts dragged on. V.FC was not compatible with V.34, although most V.34 modems could support V.FC, notably, those using Rockwell chipsets.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Wideband_modems">Wideband modems</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=4" title="Edit section: Wideband modems"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.35–V.39</i> </p> <ul><li><span class="anchor" id="V.35"></span> <b>V.35</b> is an ITU-T standard located on layer 1 on the <a href="/wiki/OSI_model" title="OSI model">OSI model</a>. Max speed is 2 Mbit/s and synchronous only. Withdrawn ITU-T recommendation for 48 kbit/s data transmission over wideband circuits. The physical and electrical characteristics of this interface are now specified in ITU-T recommendation V.11.</li> <li><span class="anchor" id="V.36"></span> <b>V.36</b> is an ITU-T standard located on layer 2 on the <a href="/wiki/OSI_model" title="OSI model">OSI model</a> called Modems For Synchronous Data Transmission Using 60–108 kHz Group Band Circuits.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Error_control_and_data_compression">Error control and data compression</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=5" title="Edit section: Error control and data compression"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.40–V.49</i> </p> <ul><li><span class="anchor" id="V.41"></span> <b>V.41</b> is a code-independent error control system. It defines the <a href="/wiki/ITU-T" title="ITU-T">ITU-T</a> standard <a href="/wiki/Cyclic_redundancy_check" title="Cyclic redundancy check">CRC-16</a> polynomial as x<sup>16</sup> + x<sup>12</sup> + x<sup>5</sup> + 1</li> <li><span class="anchor" id="V.42"></span> <b>V.42</b> is an error correction protocol. Its function is to allow the receiver to immediately request re-transmission of any lost data packets. However, it does not guarantee how quickly the error-free data will be delivered to the receiving end. V.42 is generally included in dialup modems. It also defines the ITU-T standard CRC-32 polynomial as x<sup>32</sup>+x<sup>26</sup>+x<sup>23</sup>+x<sup>22</sup>+x<sup>16</sup>+x<sup>12</sup>+x<sup>11</sup>+x<sup>10</sup>+x<sup>8</sup>+x<sup>7</sup>+x<sup>5</sup>+x<sup>4</sup>+x<sup>2</sup>+x+1, and includes the <a href="/wiki/LAPM" class="mw-redirect" title="LAPM">LAPM</a> framing protocol. <ul><li><b>V.42bis</b>, also an adaptive data compression standard, is based on the <a href="/wiki/Lempel_Ziv" class="mw-redirect" title="Lempel Ziv">Lempel Ziv</a> dynamic dictionary approach, and may go to "transparent mode," in which data is transmitted uncompressed. The specific algorithm is "<a href="/w/index.php?title=BTLZ&action=edit&redlink=1" class="new" title="BTLZ (page does not exist)">BTLZ</a>" (British Telecom Lempel Ziv), which was developed by Alan Clark (then with BT).</li></ul></li> <li><span class="anchor" id="V.44"></span> <b>V.44</b> is based on <a href="/w/index.php?title=LZJH&action=edit&redlink=1" class="new" title="LZJH (page does not exist)">LZJH</a> (Lempel-Ziv-Jeff-Heath) adaptive data compression developed by Hughes Electronics for its DirecPC satellite Internet, and incorporated into the v.92 dial-up modem standard. V.44 offers somewhat better compression performance for certain types of data than the V.42bis standard, on average allowing 15% greater throughput. For instance, a 53.3 kbit/s connection with V.44 can transmit up to 53.3×6 = 320 kbit/s using pure text. In reality, the overall data rate rarely exceeds 3:1 compression (~150 kbit/s). The compression tends to get better and worse over time due to noise on the line, or due to the transfer of already-compressed files (ZIP files, JPEG images, MP3 audio, MPEG video). At some points the modem will be sending compressed files at 53 kbit/s, uncompressed files at 160 kbit/s, and pure text at 320 kbit/s, or any value in between.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Simultaneous_transmission_of_data_and_other_signals">Simultaneous transmission of data and other signals</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=6" title="Edit section: Simultaneous transmission of data and other signals"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.60–V.99</i> </p> <ul><li><span class="anchor" id="V.61"></span> <b>V.61</b> Analog Simultaneous Voice and Data (ASVD)</li> <li><span class="anchor" id="V.70"></span> <b>V.70</b> Digital Simultaneous Voice and Data (DSVD)</li> <li><span class="anchor" id="V.80"></span> <b>V.80</b>: <a href="/wiki/Videoconferencing" class="mw-redirect" title="Videoconferencing">videoconferencing</a>. It is generally compatibilized with <a href="/wiki/H.324" title="H.324">H.324</a> standard point-to-point video telephony over regular phone lines.</li> <li><span class="anchor" id="V.90"></span> <b>V.90</b> is an ITU-T recommendation for a <a href="/wiki/Modem" title="Modem">modem</a>, allowing <a href="/wiki/56_kbit/s" class="mw-redirect" title="56 kbit/s">56 kbit/s</a> digital download and 33.6 kbit/s analog upload. It replaced two vendor standards (<a href="/wiki/56_kbit/s_modem#K56flex" class="mw-redirect" title="56 kbit/s modem">K56flex</a> and <a href="/wiki/56_kbit/s_modem#X2" class="mw-redirect" title="56 kbit/s modem">X2</a>) and was designed to allow modems from both prior standards to be flash upgraded to support it. It is also known as <i>V.Last</i> as it was anticipated to be the last standard for modems operating near the channel capacity of <a href="/wiki/Plain_old_telephone_service" title="Plain old telephone service">POTS</a> lines to be developed. V.90 is generally used in concert with the V.42bis compression standard.</li> <li><span class="anchor" id="V.91"></span> <b>V.91</b>: <i>A digital modem operating at data signalling rates of up to 64 000 bit/s for use on a 4-wire circuit switched connection and on leased point-to-point 4-wire digital circuits</i>, published in 1999</li> <li><b><a href="/wiki/ITU-T_V.92" title="ITU-T V.92">V.92</a></b> is an <a href="/wiki/ITU-T" title="ITU-T">ITU-T</a> recommendation, titled <i>Enhancements to Recommendation V.90</i>, that establishes a <a href="/wiki/Modem" title="Modem">modem</a> standard allowing <a href="/wiki/56K" class="mw-redirect" title="56K">56 kbit/s</a> download, 48 kbit/s upload rates, and the new V.44 compression method. It is intended to succeed the V.90 standards. With V.92, <a href="/wiki/Pulse-code_modulation" title="Pulse-code modulation">PCM</a> is used for both the upstream and downstream connections; previously 56K modems only used PCM for downstream data.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Interworking_with_other_networks">Interworking with other networks</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=7" title="Edit section: Interworking with other networks"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.100–V.199</i> </p> <ul><li><span class="anchor" id="V.110"></span> <b>V.110</b> is an ITU-T recommendation for using terminal adaptor functions for the connection of terminals having interfaces conforming to V-series to the <a href="/wiki/ISDN" title="ISDN">ISDN</a>.</li> <li><span class="anchor" id="V.120"></span> <b>V.120</b> is an alternative to V.110 based on the LAPD protocol.</li> <li><span class="anchor" id="V.150.1"></span> <b>V.150.1</b> is an ITU-T recommendation for using a <a href="/wiki/Modem" title="Modem">modem</a> over IP networks.</li> <li><span class="anchor" id="V.152"></span> <b>V.152</b> is an ITU-T recommendation for using Voice-Band Data over IP Networks.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Interface_layer_specifications_for_data_communication">Interface layer specifications for data communication</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=8" title="Edit section: Interface layer specifications for data communication"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.200–V.249</i> </p> <ul><li><span class="anchor" id="V.230"></span> <b>V.230</b> is an ITU-T recommendation, approved in November 1988, titled <i>General data communications interface layer 1 specification.</i></li></ul> <div class="mw-heading mw-heading2"><h2 id="Control_procedures">Control procedures</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=9" title="Edit section: Control procedures"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.250–V.299</i> </p> <ul><li><span class="anchor" id="V.250"></span> <b>V.250</b>, originally known as V.25ter, is an ITU-T recommendation for serial asynchronous automatic dialing and control.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Digital_circuit_modems">Digital circuit modems</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=10" title="Edit section: Digital circuit modems"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><i>Applies to V.300–V.399</i> </p> <ul><li><span class="anchor" id="V.300"></span> <b>V.300</b> is an ITU-T recommendation, first approved in January 1997, titled <i>A 128 (144) kbit/s data circuit-terminating equipment standardized for use on digital point-to-point leased circuits</i>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=11" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Microcom_Networking_Protocol" title="Microcom Networking Protocol">Microcom Networking Protocols</a> (MNP1 to 10)</li> <li><a href="/wiki/List_of_interface_bit_rates" title="List of interface bit rates">List of interface bit rates</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=12" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-Vseries-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-Vseries_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFITU-T2006" class="citation web cs1"><a href="/wiki/ITU-T" title="ITU-T">ITU-T</a> (2006-09-29). <a rel="nofollow" class="external text" href="http://www.itu.int/rec/T-REC-V/en">"Data communication over the telephone network"</a>. ITU<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-03-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Data+communication+over+the+telephone+network&rft.pub=ITU&rft.date=2006-09-29&rft.au=ITU-T&rft_id=http%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.32-198811-S/en">"V.32 : A family of 2-wire, duplex modems operating at data signalling rates of up to 9600 bit/s for use on the general switched telephone network and on leased telephone-type circuits"</a>. <i>www.itu.int</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-08-20</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.itu.int&rft.atitle=V.32+%3A+A+family+of+2-wire%2C+duplex+modems+operating+at+data+signalling+rates+of+up+to+9600+bit%2Fs+for+use+on+the+general+switched+telephone+network+and+on+leased+telephone-type+circuits&rft_id=https%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V.32-198811-S%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.32bis-199102-I/en">"V.32bis : A duplex modem operating at data signalling rates of up to 14 400 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits"</a>. <i>www.itu.int</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-08-20</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.itu.int&rft.atitle=V.32bis+%3A+A+duplex+modem+operating+at+data+signalling+rates+of+up+to+14+400+bit%2Fs+for+use+on+the+general+switched+telephone+network+and+on+leased+point-to-point+2-wire+telephone-type+circuits&rft_id=https%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V.32bis-199102-I%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=Sx0EAAAAMBAJ&dq=v.32terbo&pg=PA4">Vendors rallying around high-speed modem scheme</a></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.34-199409-S/en">"V.34: a modem operating at data signalling rates of up to 28 800 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits"</a>. <i>www.itu.int</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-07-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.itu.int&rft.atitle=V.34%3A+a+modem+operating+at+data+signalling+rates+of+up+to+28+800+bit%2Fs+for+use+on+the+general+switched+telephone+network+and+on+leased+point-to-point+2-wire+telephone-type+circuits&rft_id=https%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V.34-199409-S%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.34-199610-S/en">"V.34: A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits"</a>. <i>www.itu.int</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-07-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.itu.int&rft.atitle=V.34%3A+A+modem+operating+at+data+signalling+rates+of+up+to+33+600+bit%2Fs+for+use+on+the+general+switched+telephone+network+and+on+leased+point-to-point+2-wire+telephone-type+circuits&rft_id=https%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V.34-199610-S%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.34-199802-I/en">"V.34: A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits"</a>. <i>www.itu.int</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-07-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.itu.int&rft.atitle=V.34%3A+A+modem+operating+at+data+signalling+rates+of+up+to+33+600+bit%2Fs+for+use+on+the+general+switched+telephone+network+and+on+leased+point-to-point+2-wire+telephone-type+circuits&rft_id=https%3A%2F%2Fwww.itu.int%2Frec%2FT-REC-V.34-199802-I%2Fen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://encyclopedia2.thefreedictionary.com/V.Fast+Class">"V.FC"</a></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWilldigPatrik_Chen1994" class="citation web cs1">Willdig, Karl; Patrik Chen (August 1994). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20070104124418/http://fndcg0.fnal.gov/Net/modm8-94.txt">"What You Need to Know about Modems"</a>. Archived from <a rel="nofollow" class="external text" href="http://fndcg0.fnal.gov/Net/modm8-94.txt">the original</a> on 2007-01-04<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-03-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=What+You+Need+to+Know+about+Modems&rft.date=1994-08&rft.aulast=Willdig&rft.aufirst=Karl&rft.au=Patrik+Chen&rft_id=http%3A%2F%2Ffndcg0.fnal.gov%2FNet%2Fmodm8-94.txt&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMitronov2001" class="citation web cs1">Mitronov, Pavel (2001-06-29). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170202062749/https://www.pricenfees.com/digit-life-archives/modem-compression-v-44-v-42bis">"Modem compression: V.44 against V.42bis"</a>. Pricenfees.com. Archived from <a rel="nofollow" class="external text" href="https://www.pricenfees.com/digit-life-archives/modem-compression-v-44-v-42bis">the original</a> on 2017-02-02<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-03-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Modem+compression%3A+V.44+against+V.42bis&rft.pub=Pricenfees.com&rft.date=2001-06-29&rft.aulast=Mitronov&rft.aufirst=Pavel&rft_id=https%3A%2F%2Fwww.pricenfees.com%2Fdigit-life-archives%2Fmodem-compression-v-44-v-42bis&rfr_id=info%3Asid%2Fen.wikipedia.org%3AList+of+ITU-T+V-series+recommendations" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.itu.int/rec/T-REC-V.250-200203-S!Amd2/en">Supplement (04/95) to Recommendation V.25ter - Serial asynchronous automatic dialling and control</a></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=List_of_ITU-T_V-series_recommendations&action=edit&section=13" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://www.itu.int/itu-t/recommendations/index.aspx?ser=V">ITU-T Recommendations: V Series</a></li> <li><a rel="nofollow" class="external text" href="http://www.advice1.com/v35.htm">V.35 Technical Info</a> – Includes pinouts and history</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20060617021151/http://v92.com/faqs/">V.44 FAQ</a></li> <li><a rel="nofollow" class="external text" href="https://archive.today/20130119200953/http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122limit/122x/122xa/122xa_2/ftv44mca.htm">Technical information on the LZJH algorithm in use in the V.44 standard</a></li> <li><a rel="nofollow" class="external text" href="http://3amSystems.com/wireline/hmo.htm">Basic handshakes & modulations</a> – V.22, V.22bis & V.32 handshakes</li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="ITU_recommendations_(standards)527" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:ITU_standards" title="Template:ITU standards"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:ITU_standards" title="Template talk:ITU standards"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:ITU_standards" title="Special:EditPage/Template:ITU standards"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="ITU_recommendations_(standards)527" style="font-size:114%;margin:0 4em"><a href="/wiki/International_Telecommunication_Union" title="International Telecommunication Union">ITU</a> recommendations (standards)</div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><i><u>Lists:</u></i> <a class="mw-selflink selflink">List of ITU-T V-series recommendations</a></li> <li><a href="/wiki/List_of_ITU_letter_codes" title="List of ITU letter codes">List of ITU letter codes</a><br /><i><u>Categories:</u></i> <a href="/wiki/Category:ITU-R_recommendations" title="Category:ITU-R recommendations">Category:ITU-R recommendations</a></li> <li><a href="/wiki/Category:ITU-T_recommendations" title="Category:ITU-T recommendations">Category:ITU-T recommendations</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">G series (ITU-T)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/G.114" class="mw-redirect" title="G.114">G.114</a></li> <li><a href="/wiki/G.165" title="G.165">G.165</a></li> <li><a href="/wiki/G.703" title="G.703">G.703</a></li> <li><a href="/w/index.php?title=G.704&action=edit&redlink=1" class="new" title="G.704 (page does not exist)">G.704</a></li> <li><a href="/wiki/G.706" title="G.706">G.706</a></li> <li><a href="/wiki/Synchronous_optical_networking" title="Synchronous optical networking">G.707</a></li> <li><a href="/wiki/G.709" title="G.709">G.709</a></li> <li><a href="/wiki/G.711" title="G.711">G.711</a></li> <li><a href="/wiki/G.718" title="G.718">G.718</a></li> <li><a href="/wiki/G.719" title="G.719">G.719</a></li> <li><a href="/wiki/G.722" title="G.722">G.722</a></li> <li><a href="/wiki/G.722.1" title="G.722.1">G.722.1</a></li> <li><a href="/wiki/Adaptive_Multi-Rate_Wideband" title="Adaptive Multi-Rate Wideband">G.722.2</a></li> <li><a href="/wiki/G.729.1" title="G.729.1">G.729.1</a></li> <li><a href="/wiki/G.723" title="G.723">G.723</a></li> <li><a href="/wiki/G.723.1" title="G.723.1">G.723.1</a></li> <li><a href="/wiki/G.726" title="G.726">G.726</a></li> <li><a href="/wiki/G.728" title="G.728">G.728</a></li> <li><a href="/wiki/G.729" title="G.729">G.729</a></li> <li><a href="/wiki/G.783" title="G.783">G.783</a></li> <li><a href="/wiki/G.798" class="mw-redirect" title="G.798">G.798</a></li> <li><a href="/w/index.php?title=G.806&action=edit&redlink=1" class="new" title="G.806 (page does not exist)">G.806</a></li> <li><a href="/wiki/G.811" title="G.811">G.811</a></li> <li><a href="/wiki/G.983" title="G.983">G.983</a></li> <li><a href="/wiki/G.984" class="mw-redirect" title="G.984">G.984</a></li> <li><a href="/wiki/G.987" class="mw-redirect" title="G.987">G.987</a></li> <li><a href="/wiki/G.988" title="G.988">G.988</a></li> <li><a href="/wiki/High-bit-rate_digital_subscriber_line" title="High-bit-rate digital subscriber line">G.991.1</a></li> <li><a href="/wiki/Single-pair_high-speed_digital_subscriber_line" title="Single-pair high-speed digital subscriber line">G.991.2</a></li> <li><a href="/wiki/ITU_G.992.1" class="mw-redirect" title="ITU G.992.1">G.992.1</a></li> <li><a href="/wiki/ITU_G.992.2" class="mw-redirect" title="ITU G.992.2">G.992.2</a></li> <li><a href="/wiki/ITU_G.992.3" class="mw-redirect" title="ITU G.992.3">G.992.3</a> <ul><li><a href="/wiki/ITU_G.992.3_Annex_J" class="mw-redirect" title="ITU G.992.3 Annex J">Annex J</a></li> <li><a href="/wiki/ITU_G.992.3_Annex_L" class="mw-redirect" title="ITU G.992.3 Annex L">Annex L</a></li></ul></li> <li><a href="/wiki/ITU_G.992.4" class="mw-redirect" title="ITU G.992.4">G.992.4</a></li> <li><a href="/wiki/ITU_G.992.5" class="mw-redirect" title="ITU G.992.5">G.992.5</a> <ul><li><a href="/wiki/ITU_G.992.5_Annex_M" class="mw-redirect" title="ITU G.992.5 Annex M">Annex M</a></li></ul></li> <li><a href="/wiki/Very-high-bit-rate_digital_subscriber_line" class="mw-redirect" title="Very-high-bit-rate digital subscriber line">G.993.1</a></li> <li><a href="/wiki/ITU_G.993.2" class="mw-redirect" title="ITU G.993.2">G.993.2</a></li> <li><a href="/wiki/Generic_Framing_Procedure" title="Generic Framing Procedure">G.7041</a></li> <li><a href="/wiki/Link_Capacity_Adjustment_Scheme" title="Link Capacity Adjustment Scheme">G.7042</a></li> <li><a href="/w/index.php?title=G.7043&action=edit&redlink=1" class="new" title="G.7043 (page does not exist)">G.7043</a></li> <li><a href="/wiki/Synchronous_Ethernet" title="Synchronous Ethernet">G.8262</a></li> <li><a href="/wiki/G.fast" title="G.fast">G.9700, G.9701, G.9710 and G.9711</a></li> <li><a href="/wiki/G.hn" title="G.hn">G.9960</a></li> <li><a href="/wiki/ITU_G.9970" class="mw-redirect" title="ITU G.9970">G.9970</a></li> <li><a href="/wiki/ITU_G.9972" class="mw-redirect" title="ITU G.9972">G.9972</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">H series (ITU-T)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/H.222.0" class="mw-redirect" title="H.222.0">H.222.0</a></li> <li><a href="/wiki/H.225.0" class="mw-redirect" title="H.225.0">H.225.0</a></li> <li><a href="/wiki/H.235" title="H.235">H.235</a></li> <li><a href="/wiki/H.239" title="H.239">H.239</a></li> <li><a href="/wiki/H.241" title="H.241">H.241</a></li> <li><a href="/wiki/H.245" title="H.245">H.245</a></li> <li><a href="/wiki/H.248" title="H.248">H.248</a></li> <li><a href="/wiki/H.261" title="H.261">H.261</a></li> <li><a href="/wiki/H.262/MPEG-2_Part_2" title="H.262/MPEG-2 Part 2">H.262/MPEG-2 Video</a></li> <li><a href="/wiki/H.263" title="H.263">H.263</a></li> <li><a href="/wiki/Advanced_Video_Coding" title="Advanced Video Coding">H.264/MPEG-4 AVC</a></li> <li><a href="/wiki/High_Efficiency_Video_Coding" title="High Efficiency Video Coding">H.265/MPEG-H HEVC</a></li> <li><a href="/wiki/Versatile_Video_Coding" title="Versatile Video Coding">H.266/MPEG-I VVC</a></li> <li><a href="/wiki/H.320" title="H.320">H.320</a></li> <li><a href="/wiki/H.323" title="H.323">H.323</a></li> <li><a href="/wiki/H.323_Gatekeeper" title="H.323 Gatekeeper">H.323 Gatekeeper</a></li> <li><a href="/wiki/H.324" title="H.324">H.324</a></li> <li><a href="/wiki/H.450" title="H.450">H.450</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a class="mw-selflink selflink">V series</a> (ITU-T)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/RS-423" title="RS-423">V.10</a></li> <li><a href="/wiki/RS-422" title="RS-422">V.11</a></li> <li><a href="/wiki/ITU-T_V.23" title="ITU-T V.23">V.23</a></li> <li><a href="/wiki/RS-232" title="RS-232">V.24</a></li> <li><a href="/wiki/ITU-T_V.92" title="ITU-T V.92">V.92</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">ITU-R</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ITU-R_468_noise_weighting" title="ITU-R 468 noise weighting">ITU-R 468 noise weighting</a></li> <li><a href="/wiki/ITU-R_BS.1534-1" class="mw-redirect" title="ITU-R BS.1534-1">ITU-R BS.1534-1</a></li> <li><a href="/wiki/ITU-R_BT.1304" class="mw-redirect" title="ITU-R BT.1304">ITU-R BT.1304</a></li> <li><a href="/wiki/ITU-R_BT.470-6" class="mw-redirect" title="ITU-R BT.470-6">ITU-R BT.470-6</a></li> <li><a href="/wiki/ITU-R_BT.470-7" class="mw-redirect" title="ITU-R BT.470-7">ITU-R BT.470-7</a></li> <li><a href="/wiki/ITU-R_BT.601" class="mw-redirect" title="ITU-R BT.601">ITU-R BT.601</a></li> <li><a href="/wiki/ITU-R_BT.709" class="mw-redirect" title="ITU-R BT.709">ITU-R BT.709</a></li> <li><a href="/wiki/ITU-R_BT.2020" class="mw-redirect" title="ITU-R BT.2020">ITU-R BT.2020</a></li> <li><a href="/wiki/Rec._2100" title="Rec. 2100">ITU-R BT.2100</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div><i>See also:</i> <span class="plainlinks"><a class="external text" href="https://en.wikipedia.org/w/index.php?title=Special:PrefixIndex&prefix=ITU&namespace=0">All articles beginning with "ITU"</a></span></div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Telephone_network_modem_standards37" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Modem_standards" title="Template:Modem standards"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Modem_standards" title="Template talk:Modem standards"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Modem_standards" title="Special:EditPage/Template:Modem standards"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Telephone_network_modem_standards37" style="font-size:114%;margin:0 4em">Telephone network <a href="/wiki/Modem" title="Modem">modem</a> standards</div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">ITU-T V-series recommendations</a></li> <li><a href="/wiki/ITU-T_V.92" title="ITU-T V.92">V.92</a></li> <li><a href="/wiki/Modem#K56flex" title="Modem">K56flex</a></li> <li><a href="/wiki/Modem#X2" title="Modem">X2</a></li> <li><a href="/wiki/Microcom_Networking_Protocol" title="Microcom Networking Protocol">MNP</a></li> <li><a href="/wiki/Hayes_AT_command_set" title="Hayes AT command set">Hayes AT command set</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=List_of_ITU-T_V-series_recommendations&oldid=1265227066">https://en.wikipedia.org/w/index.php?title=List_of_ITU-T_V-series_recommendations&oldid=1265227066</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Modems" title="Category:Modems">Modems</a></li><li><a href="/wiki/Category:ITU-T_recommendations" title="Category:ITU-T recommendations">ITU-T recommendations</a></li><li><a href="/wiki/Category:Lists_of_standards" title="Category:Lists of standards">Lists of standards</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 25 December 2024, at 21:12<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=List_of_ITU-T_V-series_recommendations&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" lang="en" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><picture><source media="(min-width: 500px)" srcset="/w/resources/assets/poweredby_mediawiki.svg" width="88" height="31"><img src="/w/resources/assets/mediawiki_compact.svg" alt="Powered by MediaWiki" width="25" height="25" loading="lazy"></picture></a></li> </ul> </footer> </div> </div> </div> <div class="vector-header-container vector-sticky-header-container"> <div id="vector-sticky-header" class="vector-sticky-header"> <div class="vector-sticky-header-start"> <div class="vector-sticky-header-icon-start vector-button-flush-left vector-button-flush-right" aria-hidden="true"> <button class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-sticky-header-search-toggle" tabindex="-1" data-event-name="ui.vector-sticky-search-form.icon"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </button> </div> <div role="search" class="vector-search-box-vue vector-search-box-show-thumbnail vector-search-box"> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail"> <form action="/w/index.php" id="vector-sticky-search-form" class="cdx-search-input cdx-search-input--has-end-button"> <div class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia"> <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <div class="vector-sticky-header-context-bar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-sticky-header-toc" class="vector-dropdown mw-portlet mw-portlet-sticky-header-toc vector-sticky-header-toc vector-button-flush-left" > <input type="checkbox" id="vector-sticky-header-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-sticky-header-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-sticky-header-toc-label" for="vector-sticky-header-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-sticky-header-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div class="vector-sticky-header-context-bar-primary" aria-hidden="true" ><span class="mw-page-title-main">List of ITU-T V-series recommendations</span></div> </div> </div> <div class="vector-sticky-header-end" aria-hidden="true"> <div class="vector-sticky-header-icons"> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-talk-sticky-header" tabindex="-1" data-event-name="talk-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbles mw-ui-icon-wikimedia-speechBubbles"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-subject-sticky-header" tabindex="-1" data-event-name="subject-sticky-header"><span class="vector-icon mw-ui-icon-article mw-ui-icon-wikimedia-article"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-history-sticky-header" tabindex="-1" data-event-name="history-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-history mw-ui-icon-wikimedia-wikimedia-history"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only mw-watchlink" id="ca-watchstar-sticky-header" tabindex="-1" data-event-name="watch-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-star mw-ui-icon-wikimedia-wikimedia-star"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-edit-sticky-header" tabindex="-1" data-event-name="wikitext-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-wikiText mw-ui-icon-wikimedia-wikimedia-wikiText"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-ve-edit-sticky-header" tabindex="-1" data-event-name="ve-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-edit mw-ui-icon-wikimedia-wikimedia-edit"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-viewsource-sticky-header" tabindex="-1" data-event-name="ve-edit-protected-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-editLock mw-ui-icon-wikimedia-wikimedia-editLock"></span> <span></span> </a> </div> <div class="vector-sticky-header-buttons"> <button class="cdx-button cdx-button--weight-quiet mw-interlanguage-selector" id="p-lang-btn-sticky-header" tabindex="-1" data-event-name="ui.dropdown-p-lang-btn-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-language mw-ui-icon-wikimedia-wikimedia-language"></span> <span>3 languages</span> </button> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive" id="ca-addsection-sticky-header" tabindex="-1" data-event-name="addsection-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbleAdd-progressive mw-ui-icon-wikimedia-speechBubbleAdd-progressive"></span> <span>Add topic</span> </a> </div> <div class="vector-sticky-header-icon-end"> <div class="vector-user-links"> </div> </div> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-b766959bd-2wsjz","wgBackendResponseTime":127,"wgPageParseReport":{"limitreport":{"cputime":"0.327","walltime":"0.401","ppvisitednodes":{"value":1087,"limit":1000000},"postexpandincludesize":{"value":34668,"limit":2097152},"templateargumentsize":{"value":296,"limit":2097152},"expansiondepth":{"value":8,"limit":100},"expensivefunctioncount":{"value":1,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":46614,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 339.051 1 -total"," 41.57% 140.943 1 Template:Reflist"," 34.15% 115.774 8 Template:Cite_web"," 23.74% 80.492 1 Template:ITU_standards"," 23.40% 79.353 2 Template:Navbox"," 22.16% 75.129 1 Template:Short_description"," 13.44% 45.585 2 Template:Pagetype"," 8.59% 29.111 35 Template:Anchor"," 4.91% 16.640 3 Template:Main_other"," 4.16% 14.090 1 Template:SDcat"]},"scribunto":{"limitreport-timeusage":{"value":"0.200","limit":"10.000"},"limitreport-memusage":{"value":4545542,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-84b999ff94-d84n4","timestamp":"20250204094700","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"List of ITU-T V-series recommendations","url":"https:\/\/en.wikipedia.org\/wiki\/List_of_ITU-T_V-series_recommendations","sameAs":"http:\/\/www.wikidata.org\/entity\/Q2624253","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q2624253","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2006-06-04T13:52:20Z","dateModified":"2024-12-25T21:12:16Z"}</script> </body> </html>