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<!DOCTYPE html>
<html lang="en" dir="ltr" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Microsoft Object RTC (ORTC) Implementation</title>
<meta charset='utf-8'>
<script src="respec-w3c-common.js" async class="remove"></script>
<script src="respec-config.js" class="remove"></script>
</head>
<body>
<section id="abstract">
<p>This document describes the Microsoft Edge ORTC API supported in the
Windows 10 Fall Creators Update, as of October 2017.</p>
<p>The Microsoft Edge ORTC API implementation differs from the most recent version of the
<a href="http://draft.ortc.org/">ORTC API</a> since ORTC has continued to evolve since the development of
Microsoft Edge got underway. In addition, Microsoft Edge does not implement every object or method
within the ORTC API, and includes some extensions not currently incorporated within the specification.
Since both Microsoft Edge and this document represent works-in-progress, the behavior of Microsoft Edge can
change substantially from build-to-build. Please bring questions, errors and omissions to the attention of the
Edge RTC team (Bernard Aboba, bernarda@microsoft and Angelina Gambo, [email protected]).
</p>
</section>
<section id='sotd'>
</section>
<section id="overview*">
<h2><span class="secno"> </span>Overview</h2>
<p>Microsoft's Object Real-Time Communications (ORTC) API implementation enables the development of realtime communications applications.
Within Microsoft's implementation,
the relationship between the application and the objects, as well
as between the objects themselves is shown below.
Horizontal or slanted arrows denote the flow of media or data,
whereas vertical arrows denote interactions via methods and events.
</p>
<img alt="The non-normative ORTC Big Picture Diagram" src="images/msortc-big-picture.svg" style="width:100%" />
<p>In the figure above, the <code><a>RTCRtpSender</a></code> (<a href="#rtcrtpsender*">Section 6</a>) encodes the
track provided as input, which is transported over a <code><a>RTCDtlsTransport</a></code>
(<a href="#rtcdtlstransport*">Section 4</a>) or an <code><a>RTCSrtpSdesTransport</a></code>
(<a href="#rtcsrtpsdestransport*">Section 5</a>).
Sending of Dual Tone Multi Frequency (DTMF) tones is supported via the
<code><a>RTCDtmfSender</a></code> (<a href="#rtcdtmfsender*">Section 9</a>).</p>
<p>The <code><a>RTCDtlsTransport</a></code> and <code><a>RTCSrtpSdesTransport</a></code> utilize an <code><a>RTCIceTransport</a></code>
(<a href="#rtcicetransport*">Section 3</a>) to select a communication path to reach the
receiving peer's <code><a>RTCIceTransport</a></code>, which is in turn associated with
an <code><a>RTCDtlsTransport</a></code> or <code><a>RTCSrtpSdesTransport</a></code> which de-multiplexes
media to the <code><a>RTCRtpReceiver</a></code> (<a href="#rtcrtpreceiver*">Section 7</a>).
The <code><a>RTCRtpReceiver</a></code> then decodes media, producing a track which is rendered
by an audio or video tag.</p>
<p>Several other objects also play a role.
The <code><a>RTCIceGatherer</a></code> (<a href="#rtcicegatherer*">Section 2</a>) gathers local ICE candidates for use by a single
<code><a>RTCIceTransport</a></code> object.</p>
<div class="note">
<p>Edge Interop Note: Since Microsoft Edge does not implement the data channel, the <code>RTCDataChannel</code> and <code>RTCSctpTransport</code> objects are not supported.
</p>
</div>
<p>Remaining sections of the specification fill in details relating to RTP capabilities and parameters,
operational statistics and compatibility with the
WebRTC 1.0 API.
RTP dictionaries are described in <a href="#rtcrtpdictionaries*">Section 8</a>,
the Statistics API is described in <a href="#statistics-api">Section 10</a>,
Microsoft extensions related to the H.264UC codec [[MS-H264PF]] and statistics are described in <a href="#msextensions*">Section 11</a>,
an event summary is provided in <a href="#event-summary">Section 12</a>,
a list of error codes is provided in <a href="#error-codes*">Section 13</a>
and WebRTC 1.0 compatibility issues are discussed in <a href="#webrtc-compat*">Section 14</a>.
</p>
<p>Complete examples are provided in <a href="#examples*">Section 15</a>.</p>
</div>
<section>
<h3>Terminology</h3>
<p>The <code><a href=
"http://dev.w3.org/html5/spec/webappapis.html#eventhandler">EventHandler</a></code>
interface represents a callback used for event handlers as defined in
[[!HTML5]].</p>
<p>The concepts <dfn><a href=
"http://dev.w3.org/html5/spec/webappapis.html#queue-a-task">queue a
task</a></dfn> and <dfn><a href=
"http://dev.w3.org/html5/spec/webappapis.html#fire-a-simple-event">fires a
simple event</a></dfn> are defined in [[!HTML5]].</p>
<p>The terms <dfn>event</dfn>, <dfn><a href=
"http://dev.w2.org/html5/spec/webappapis.html#event-handlers">event
handlers</a></dfn> and <dfn><a href=
"http://dev.w3.org/html5/spec/webappapis.html#event-handler-event-type">event
handler event types</a></dfn> are defined in [[!HTML5]].</p>
<p>The terms <dfn>MediaStream</dfn> and <dfn>MediaStreamTrack</dfn>
are defined in
[[!GETUSERMEDIA]].</p>
<p>For Scalable Video Coding (SVC), the terms single-session transmission (<dfn>SST</dfn>) and multi-session transmission (<dfn>MST</dfn>)
are defined in [[RFC6190]]. This specification only supports <a>SST</a> but not <a>MST</a>.
The term Single Real-time transport protocol stream Single Transport (<dfn>SRST</dfn>),
defined in [[RFC7656]] Section 3.7, refers to an SVC implementation that transmits all layers within a
single transport, using a single Real-time Transport Protocol (RTP) stream and synchronization source (SSRC).
The term Multiple RTP stream Single Transport (<dfn>MRST</dfn>), also defined in [[RFC7656]] Section 3.7, refers
to an implementation that transmits all layers within a single transport, using multiple RTP streams with
a distinct SSRC for each layer.</p>
</section>
</section>
<section id="rtcicegatherer*">
<h2>The RTCIceGatherer Object</h2>
<p>
The <dfn>RTCIceGatherer</dfn> gathers local host, server reflexive and relay candidates, as
well as enabling the retrieval of local Interactive Connectivity Establishment (ICE) parameters which can be exchanged in signaling.
</p>
<section id="rtcicegatherer-overview*">
<h3>Overview</h3>
<p>The Microsoft Edge implementation of the <code><a>RTCIceGatherer</a></code> does not support
the <var>component</var> or <var>state</var> attributes, nor does it support the
<code>close()</code> method or the <code>ongatherstatechange</code> event handler.
</p>
<div class="note">
<p>Edge Interop Note: In the Microsoft Edge implementation, an <code><a>RTCIceGatherer</a></code> instance can only
be associated to a single <code><a>RTCIceTransport</a></code>
object. As a result, forking scenarios are not supported.
The <code><a>RTCIceGatherer</a></code> prunes local candidates when its
associated <code><a>RTCIceTransport</a></code> object enters the "completed" state.
</p>
</div>
<p>As noted in [[!RFC5245]] Section 7.1.2.2, an incoming connectivity check contains an <code>ICE-CONTROLLING</code>
or <code>ICE-CONTROLLED</code> attribute, depending on the role of the ICE agent initiating the check.
Since an <code><a>RTCIceGatherer</a></code> object does not have a role, it cannot determine whether
to respond to an incoming connectivity check with a 487 (Role Conflict) error; however, it can validate
that an incoming connectivity check utilizes the correct local username fragment and password,
and if not, can respond with an
401 (Unauthorized) error, as described in [[!RFC5389]] Section 10.1.2.</p>
<p>For incoming connectivity checks that pass validation, the <code><a>RTCIceGatherer</a></code>
<em class="rfc2119" title="MUST">MUST</em>
buffer incoming connectivity checks so as to be able to provide them to associated
<code><a>RTCIceTransport</a></code> objects so that they can respond.</p>
</section>
<section id="rtcicegatherer-operation*">
<h3>Operation</h3>
<p>An <code><a>RTCIceGatherer</a></code> instance is constructed from an
<code><a>RTCIceGatherOptions</a></code> object.
. If <code><a>RTCIceGatherOptions</a>.portRange</code>
is invalid (e.g. <code>portRange.max</code> < <code>portRange.min</code>),
throw an <code>InvalidParameters</code> exception.</p>
</section>
<section id="rtcicegatherer-interface-definition*">
<h3>Interface Definition</h3>
<dl class="idl" title="[Constructor(RTCIceGatherOptions options)] interface RTCIceGatherer : RTCStatsProvider">
<dt>readonly attribute RTCIceComponent component</dt>
<dd><p>The component-id of the <code><a>RTCIceGatherer</a></code>.</p></dd>
<dt>RTCIceParameters getLocalParameters()</dt>
<dd><p>Obtain the ICE parameters of the <code><a>RTCIceGatherer</a></code>.</p></dd>
<dt>sequence<RTCIceCandidate> getLocalCandidates()</dt>
<dd><p>Retrieve the sequence of valid local candidates associated with the
<code><a>RTCIceGatherer</a></code>.
This retrieves all unpruned local candidates currently known (except for peer reflexive candidates),
even if an <code><a>onlocalcandidate</a></code>
event hasn't been processed yet. In Microsoft Edge, if <code>getLocalCandidates()</code> is called prior to emitting of the
first candidate, an exception is thrown.
</p></dd>
<dt>RTCIceGatherer createAssociatedGatherer()</dt>
<dd><p>Create an associated <code><a>RTCIceGatherer</a></code> for RTCP, with the same
<code><a>RTCIceParameters</a></code> and <code><a>RTCIceGatherOptions</a></code>.
If an <code><a>RTCIceGatherer</a></code> calls the method more than once,
or if <var>component</var> is "RTCP", throw
an <code>InvalidStateError</code> exception.
</p></dd>
<dt>attribute EventHandler? onerror</dt>
<dd><p>This event handler, of event handler type <code>error</code>,
<em class="rfc2119" title="MUST">MUST</em> be supported by all objects
implementing the <code><a>RTCIceGatherer</a></code> interface.
If TURN credentials are invalid, or a port cannot be allocated for a local ICE candidate, then this event <em class="rfc2119" title="MUST">MUST</em>
be fired.
</p></dd>
<dt>attribute EventHandler? onlocalcandidate</dt>
<dd><p>This event handler, of event handler event type <code>icecandidate</code>, uses
the <code><a>RTCIceGathererEvent</a></code> interface.
It <em class="rfc2119" title="MUST">MUST</em> be supported by all objects implementing the
<code><a>RTCIceGatherer</a></code> interface.
It receives events when a new local ICE candidate is available. Since ICE candidate gathering begins once
an <code><a>RTCIceGatherer</a></code> object is created,
<code>candidate</code> events are queued until an <code>onlocalcandidate</code> event handler is assigned.
When the final candidate is gathered, a <code>candidate</code> event occurs with an <code>RTCIceCandidateComplete</code> emitted.
</p></dd>
</dl>
</section>
<section id="rtciceparameters*">
<h3>The RTCIceParameters Object</h3>
<p>
The <dfn>RTCIceParameters</dfn> object includes the ICE username fragment and password, as well as an indication of whether ICE lite is supported.
</p>
<dl class="idl" title="dictionary RTCIceParameters">
<dt>DOMString usernameFragment</dt>
<dd><p>ICE username.</p></dd>
<dt>DOMString password</dt>
<dd><p>ICE password.</p></dd>
<dt>boolean? iceLite</dt>
<dd>Whether ICE lite is supported (true) or not (false). If unset, ICE lite is not supported.
Since browsers support full ICE, <code>getLocalParameters().iceLite</code> MUST NOT be set. This
attribute is only set in remote parameters signaled by a remote peer (such as a gateway) that only supports ICE lite.</dd>
</dl>
</section>
<section id="rtcicecandidate*">
<h3>The RTCIceCandidate Object</h3>
<p>
The <dfn>RTCIceCandidate</dfn> object includes information relating to an ICE candidate.
</p>
<pre xml:space="preserve" class='example highlight'>
foundation: "abcd1234",
priority: 1694498815,
ip: "192.0.2.33",
protocol: "udp",
port: 10000,
type: "host"
};
</pre>
<dl class="idl" title="typedef (RTCIceCandidate or RTCIceCandidateComplete) RTCIceGatherCandidate">
</dl>
<dl class="idl" title="dictionary RTCIceCandidate">
<dt>DOMString foundation</dt>
<dd>
<p>A unique identifier that allows ICE to correlate candidates that appear on multiple <code><a>RTCIceTransport</a></code>s.</p>
</dd>
<dt>unsigned long priority</dt>
<dd><p>The assigned priority of the candidate. This is automatically populated by the browser.</p></dd>
<dt>DOMString ip</dt>
<dd><p>The IP address of the candidate.</p></dd>
<dt>RTCIceProtocol protocol</dt>
<dd><p>The protocol of the candidate (UDP/TCP).</p></dd>
<dt>unsigned short port</dt>
<dd><p>The port for the candidate.</p></dd>
<dt>DOMString interfaceType</dt>
<dd><p>The interface type for the candidate. Types include "lan", "wlan", "wwan" and "vpn".
Not supported in Microsoft Edge.</p></dd>
<dt>RTCIceCandidateType type</dt>
<dd><p>The type of candidate.</p></dd>
<dt>RTCIceTcpCandidateType tcpType=null</dt>
<dd><p>The type of TCP candidate.</p></dd>
<dt>DOMString relatedAddress=""</dt>
<dd>
<p>For candidates that are derived from others, such as relay or reflexive candidates, the <dfn>relatedAddress</dfn>
refers to the candidate that these are derived from. For host candidates, the <var>relatedAddress</var>
is set to the empty string.</p>
</dd>
<dt>unsigned short relatedPort=null</dt>
<dd>
<p>For candidates that are derived from others, such as relay or reflexive candidates, the <dfn>relatedPort</dfn>
refers to the host candidate that these are derived from. For host candidates, the <var>relatedPort</var>
is null.</p>
</dd>
<dt>DOMString msMTurnSessionId</dt>
<dd><p>The assigned MTURN session identifier of the candidate. This is only set when an MSTURN URI is provided in the <code><a>RTCIceServer</a></code> object.</p></dd>
</dl>
<section>
<h4>The RTCIceProtocol</h4>
<p>
The <dfn>RTCIceProtocol</dfn> includes the protocol of the ICE candidate.
</p>
<dl class="idl" title="enum RTCIceProtocol">
<dt>udp</dt>
<dd><p>A UDP candidate, as described in [[!RFC5245]].</p></dd>
<dt>tcp</dt>
<dd><p>A TCP candidate, as described in [[!RFC6544]].</p></dd>
</dl>
</section>
<section>
<h4>The RTCIceTcpCandidateType</h4>
<p>
The <dfn>RTCIceTcpCandidateType</dfn> includes the type of the ICE TCP candidate, as described in [[!RFC6544]].
Browsers MUST gather active TCP candidates and only active TCP candidates.
Servers and other endpoints MAY gather active, passive or so candidates.
</p>
<dl class="idl" title="enum RTCIceTcpCandidateType">
<dt>active</dt>
<dd><p>An active TCP candidate is one for which the transport will
attempt to open an outbound connection but will not receive incoming
connection requests.</p></dd>
<dt>passive</dt>
<dd><p>A passive TCP candidate is one for which the transport
will receive incoming connection attempts but not attempt a
connection.</p></dd>
<dt>so</dt>
<dd><p>An so candidate is one for which the transport will attempt
to open a connection simultaneously with its peer.</p></dd>
</dl>
</section>
<section>
<h4>The RTCIceCandidateType</h4>
<p>
The <dfn>RTCIceCandidateType</dfn> includes the type of the ICE candidate.
</p>
<dl class="idl" title="enum RTCIceCandidateType">
<dt>host</dt>
<dd><p>A host candidate.</p></dd>
<dt>srflx</dt>
<dd><p>A server reflexive candidate.</p></dd>
<dt>prflx</dt>
<dd><p>A peer reflexive candidate.</p></dd>
<dt>relay</dt>
<dd><p>A relay candidate.</p></dd>
</dl>
</section>
</section>
<section id="rtcicecandidatecomplete*">
<h3>dictionary RTCIceCandidateComplete</h3>
<p>
<dfn>RTCIceCandidateComplete</dfn> is a dictionary signifying that all <code>RTCIceCandidate</code>s are gathered.
<p>
<dl class="idl" title="dictionary RTCIceCandidateComplete">
</dl>
</section>
<section>
<h4>RTCIceGathererEvent</h4>
<p>The <code>icecandidate</code> event of the <code><a>RTCIceGatherer</a></code> object uses
the <code><a>RTCIceGathererEvent</a></code> interface.</p>
<p>Firing an
<code><a>RTCIceGathererEvent</a></code> event named
<var>e</var> with an <code><a>RTCIceGatherCandidate</a></code>
<var>candidate</var> means that an event with the name <var>e</var>,
which does not bubble (except where otherwise stated) and is not
cancelable (except where otherwise stated), and which uses the
<code><a>RTCIceGathererEvent</a></code> interface with the
<var>candidate</var> attribute set to the new ICE candidate,
<em class="rfc2119" title="MUST">MUST</em> be
created and dispatched at the given target.</p>
<dl class="idl" data-merge="RTCIceGathererEventInit" title=
"[Constructor(DOMString type, RTCIceGathererEventInit eventInitDict)] interface RTCIceGathererEvent : Event">
<dt>readonly attribute RTCIceGatherCandidate candidate</dt>
<dd>
<p>The <var>candidate</var> attribute is the
<code><a>RTCIceGatherCandidate</a></code> object with the new ICE
candidate that caused the event.
If <var>candidate</var> is of type <code>RTCIceCandidateComplete</code>,
there are no additional candidates.
</p>
</dd>
</dl>
<dl class="idl" title=
"dictionary RTCIceGathererEventInit : EventInit">
<dt>RTCIceGatherCandidate candidate</dt>
<dd>
<p>The ICE candidate that caused the event.</p>
</dd>
</dl>
</section>
<section id="rtcicegatheroptions*">
<h3>dictionary RTCIceGatherOptions</h3>
<p><dfn>RTCIceGatherOptions</dfn> provides options relating to the gathering of ICE candidates.</p>
<dl class="idl" title=
"dictionary RTCIceGatherOptions">
<dt>RTCIceGatherPolicy gatherPolicy</dt>
<dd><p>The ICE gather policy.</p></dd>
<dt>sequence<RTCIceServer> iceservers</dt>
<dd><p>The ICE servers to be configured.</p></dd>
<dt>MSPortRange portRange</dt>
<dd><p>The port range to use for local candidates</p></dd>
</dl>
</section>
<section id="msportrange*">
<h3>dictionary MSPortRange</h3>
<dl title='dictionary MSPortRange' class='idl'>
<dt>unsigned short min</dt>
<dd><p>Beginning of the port range.</p></dd>
<dt>unsigned short max</dt>
<dd><p>End of the port range.</p></dd>
</dl>
</section>
<section id="rtcicegatherpolicy*">
<h3>enum RTCIceGatherPolicy</h3>
<p><dfn>RTCIceGatherPolicy</dfn> denotes the policy relating to the gathering of ICE candidates.</p>
<dl class="idl" title="enum RTCIceGatherPolicy">
<dt>all</dt>
<dd><p>The ICE gatherer gathers all types of candidates when this value is specified.</p></dd>
<dt>nohost</dt>
<dd><p>The ICE gatherer gathers all ICE candidate types except for host candidates.</p></dd>
<dt>relay</dt>
<dd><p>The ICE gatherer <em class="rfc2119" title="MUST">MUST</em> only gather media relay
candidates such as candidates passing through a TURN server. This can be used to reduce
leakage of IP addresses in certain use cases.</p></dd>
</dl>
</section>
<section id="rtciceserver*">
<h3>The RTCIceServer Object</h3>
<p>
The <dfn>RTCIceServer</dfn> is used to provide STUN or TURN server configuration.
In network topologies with multiple layers of NATs, it is desirable to have a STUN server
between every layer of NATs in addition to the TURN servers to minimize the peer to peer network latency.
<p>
</p>
An example of an array of <code<<a>RTCIceServer</a></code> objects supporting the STUN and TURN standards:
</p>
<pre xml:space="preserve" class='example highlight'>
[ { urls: "stun:stun1.example.net" } ,
{ urls:"turn:turn.example.org", username: "user", credential:"myPassword"}
]
</pre>
</p>
An example of an array of <code<<a>RTCIceServer</a></code> objects supporting [[MS-TURN]]:
</p>
<pre xml:space="preserve" class='example highlight'>
[ { urls: "stun:stun1.example.net" } ,
{ urls:"msturn:turn.example.org", username: "user", credential:"myPassword"},
{ urls:"msturn-v2:turn2.example.org", username: "user", credential:"myPassword"}
]
</pre>
<div class="note">
<p>Edge Interop Note: Inclusion of the MSTURN or MSTURN-V2 URI triggers use of a proprietary TURN variant described in [[MS-TURN]], as well as proprietary ICE behavior
described in [[MS-ICE]] and [[MS-ICE2]].
The MSTURN or MSTURN-V2 URI should therefore not be used in scenarios requiring interoperability with other browsers.
The STUN URI is not currently supported.
</p>
</div>
<dl class="idl" title="dictionary RTCIceServer">
<dt>(DOMString or sequence<DOMString>) urls</dt>
<dd><p>STUN or TURN URI(s) as defined in [[!RFC7064]] and [[!RFC7065]] or other URI types (such as the MSTURN URI, described in [[MS-TURN]]).</p></dd>
<dt>DOMString username</dt>
<dd><p>If this <code><a>RTCIceServer</a></code> object represents a TURN server, then this attribute specifies
the username to use with that TURN server.</p></dd>
<dt>DOMString credential</dt>
<dd><p>If this <code><a>RTCIceServer</a></code> represents a TURN server, then this attribute specifies the credential to use with that TURN server.</p></dd>
</dl>
</section>
<section id="rtcicegatherer-initial-example*">
<h3>Example</h3>
<pre xml:space="preserve" class='example highlight'>
// Include some helper functions
import "helper.js";
// Create ICE gather options
var gatherOptions = new RTCIceGatherOptions();
gatherOptions.gatherPolicy = RTCIceGatherPolicy.relay;
gatherOptions.iceservers = [ { urls: "stun:stun1.example.net" } ,
{ urls:"turn:turn.example.org", username: "user", credential:"myPassword"} ];
// Create ICE gatherer objects
var iceGatherer = new RTCIceGatherer(gatherOptions);
// Prepare to signal local candidates as well as "end of candidates"
iceGatherer.onlocalcandidate = function (event) {
mySendLocalCandidate(event.candidate);
};
// Set up response function
mySignaller.onResponse = function(responseSignaller,response) {
// The Microsoft Edge ORTC implementation only supports a single response.
};
mySignaller.send({
"ice": iceGatherer.getLocalParameters()
});
</pre>
<pre xml:space="preserve" class='example highlight'>
// Helper functions used in all the examples (helper.js)
function trace(text) {
// This function is used for logging.
if (text[text.length - 1] === '\n') {
text = text.substring(0, text.length - 1);
}
if (window.performance) {
var now = (window.performance.now() / 1000).toFixed(3);
console.log(now + ': ' + text);
} else {
console.log(text);
}
}
function errorHandler (error) {
trace('Error encountered: ' + error.name);
}
function mySendLocalCandidate(candidate, component, kind){
// Set default values
kind = kind || "all";
component = component || RTCIceComponent.RTP;
parameters = parameters || null;
// Signal the local candidate
mySignaller.mySendLocalCandidate({
"candidate": candidate,
"component": component,
"kind": kind
});
}
function myIceTransportStateChange(name, state){
switch(state){
case RTCIceTransportState.new:
trace('IceTransport: ' + name + ' Has been created');
break;
case RTCIceTransportState.checking:
trace('IceTransport: ' + name + ' Is checking');
break;
case RTCIceTransportState.connected:
trace('IceTransport: ' + name + ' Is connected');
break;
case RTCIceTransportState.disconnected:
trace('IceTransport: ' + name + ' Is disconnected');
break;
case RTCIceTransportState.completed:
trace('IceTransport: ' + name + ' Has finished checking (for now)');
break;
case RTCIceTransportState.closed:
trace('IceTransport: ' + name + ' Is closed');
break;
default:
trace('IceTransport: ' + name + ' Invalid state');
}
}
function myDtlsTransportStateChange(name, state){
switch(state){
case RTCDtlsTransportState.new:
trace('DtlsTransport: ' + name + ' Has been created');
break;
case RTCDtlsTransportState.connecting:
trace('DtlsTransport: ' + name + ' Is connecting');
break;
case RTCDtlsTransportState.connected:
trace('DtlsTransport: ' + name + ' Is connected');
break;
case RTCDtlsTransportState.closed:
trace('DtlsTransport: ' + name + ' Is closed');
break;
default:
trace('DtlsTransport: ' + name + ' Invalid state');
}
}
</pre>
</section>
</section>
<section id="rtcicetransport*">
<h2>The RTCIceTransport Object</h2>
<p>
The <dfn>RTCIceTransport</dfn> includes information relating to Interactive Connectivity Establishment (ICE).
</p>
<section id="rtcicetransport-overview*">
<h3>Overview</h3>
<p>An <code><a>RTCIceTransport</a></code> instance is associated to a transport object (such as <code><a>RTCDtlsTransport</a></code>),
and provides RTC related methods to it. The Microsoft Edge implementation does not support the <code>oncandidatepairchange</code>
event handler.</p>
<div class="note">
<p>Edge Interop Note: The Microsoft Edge ICE implementation only supports regular nomination. In connectivity checks that it sends, Edge will
only set the USE-CANDIDATE flag for the selected pair. Also, Edge will only respond to the first connectivity check setting the
USE-CANDIDATE flag, and will ignore all subsequent connectivity checks with the USE-CANDIDATE flag set.</p>
</div>
</section>
<section id="rtcicetransport-operation*">
<h3>Operation</h3>
<p>An <code><a>RTCIceTransport</a></code> instance is constructed from an optional <code><a>RTCIceGatherer</a></code> object.</p>
</section>
<section id="rtcicetransport-interface-definition*">
<h3>Interface Definition</h3>
<dl class="idl" title="[Constructor(optional RTCIceGatherer gatherer)] interface RTCIceTransport : RTCStatsProvider">
<dt>readonly attribute RTCIceGatherer? iceGatherer</dt>
<dd><p>
The <var>iceGatherer</var> attribute is set to the value of <var>gatherer</var> passed in the constructor or the
latest call to <code>start()</code>.
</p></dd>
<dt>readonly attribute RTCIceRole role</dt>
<dd><p>The current role of the ICE transport.</p></dd>
<dt>readonly attribute RTCIceComponent component</dt>
<dd><p>The component-id of the <code><a>RTCIceTransport</a></code>.</p></dd>
<dt>readonly attribute RTCIceTransportState state</dt>
<dd><p>The current state of the ICE transport.</p></dd>
<dt>sequence<RTCIceCandidate> getRemoteCandidates()</dt>
<dd><p>Retrieve the sequence of candidates associated with the remote
<code><a>RTCIceTransport</a></code>. Only returns the candidates previously
added using <code>setRemoteCandidates()</code> or <code>addRemoteCandidate()</code>.</p></dd>
<dt>RTCIceCandidatePair? getNominatedCandidatePair()</dt>
<dd><p>Retrieves the selected candidate pair on which media is flowing. If there is no selected pair yet,
or consent is lost on the selected pair, NULL is returned.
</p></dd>
<dt>void start(RTCIceGatherer gatherer, RTCIceParameters remoteParameters, optional RTCIceRole role)</dt>
<dd><p>The first time <code>start()</code> is called, candidate connectivity checks are started and the
ICE transport attempts to connect to the remote <code><a>RTCIceTransport</a></code>.
If <code>remoteParameters.iceLite</code> is "true" then the remote peer supports ICE lite; if it is "false" or unset
then the remote peer supports full ICE.
If <code>start()</code> is called with invalid parameters, throw an <code>InvalidParameters</code> exception.
For example, if <var>gatherer.component</var>
has a value different from <var>iceTransport.component</var>, throw an <code>InvalidParameters</code> exception.
If <var>state</var> is "closed",
throw an <code>InvalidStateError</code> exception.
When <code>start()</code> is called again, <code><a>RTCIceTransportState</a></code> transitions to the "connected" state,
all remote candidates are flushed, and <code>addRemoteCandidate()</code> or
<code>setRemoteCandidates()</code> must be called to add the remote candidates back or replace them.</p><p>
If <code>start()</code>
is called again, an <code>InvalidStateError</code> exception is thrown.
</p>
<p>As noted in [[!RFC5245]] Section 7.1.2.3, an incoming connectivity check utilizes the local/remote username fragment
and the local password, whereas an outgoing connectivity check utilizes the local/remote username fragment and the
remote password. Since <code>start()</code> provides role information, as well as the remote username fragment and password,
once <code>start()</code> is called an <code><a>RTCIceTransport</a></code> object
can respond to incoming connectivity checks based on its configured role, as well as initiating connectivity checks.</p>
</dd>
<dt>void stop()</dt>
<dd><p>Stops and closes the current object.
Calling <code>stop()</code> when <var>state</var> is "closed" has no effect.
</p></dd>
<dt>RTCIceParameters? getRemoteParameters()</dt>
<dd><p>Obtain the current ICE parameters of the remote <code><a>RTCIceTransport</a></code>.</p></dd>
<dt>RTCIceTransport createAssociatedTransport ()</dt>
<dd><p>Create an associated <code><a>RTCIceTransport</a></code> for RTCP.
If called more than once for the same component, or if <var>state</var> is "closed",
throw an <code>InvalidStateError</code> exception. If called when
<var>component</var> is "RTCP",
throw an <code>InvalidStateError</code> exception.
</p></dd>
<dt>void addRemoteCandidate(RTCIceGatherCandidate remoteCandidate)</dt>
<dd><p>Add a remote candidate associated with the remote <code><a>RTCIceTransport</a></code>.
If <var>state</var> is "closed", throw an <code>InvalidStateError</code> exception.
Since Microsoft Edge only supports "half-trickle", Edge will not begin candidate pair checks until <code>RTCIceComplete</code>
has been passed as an argument to <code>addRemoteCandidate()</code>.
</p></dd>
<dt>void setRemoteCandidates(sequence<RTCIceCandidate> remoteCandidates)</dt>
<dd><p>Set the sequence of candidates associated with the remote <code><a>RTCIceTransport</a></code>.
If <var>state</var> is "closed", throw an <code>InvalidStateError</code> exception.
</p></dd>
<dt>attribute EventHandler? onicestatechange</dt>
<dd><p>This event handler, of event handler type <code>icestatechange</code>,
uses the <code>RTCIceTransportStateChangedEvent</code> interface.
It <em class="rfc2119" title="MUST">MUST</em> be supported by
all objects implementing the <code><a>RTCIceTransport</a></code> interface.
It is called any time the <code><a>RTCIceTransportState</a></code> changes.
<p></dd>
</dl>
</section>
<section id="rtcicecomponent*">
<h3>enum RTCIceComponent</h3>
<p><dfn>RTCIceComponent</dfn> contains the component-id of the <code><a>RTCIceTransport</a></code>, which will be "RTP" unless RTP and RTCP are not multiplexed and
the <code><a>RTCIceTransport</a></code> object was returned by <code>createAssociatedTransport()</code>.</p>
<dl class="idl" title="enum RTCIceComponent">
<dt>RTP</dt>
<dd><p>The RTP component ID, defined (as '1') in [[!RFC5245]] Section 4.1.1.1.
</p></dd>
<dt>RTCP</dt>
<dd><p>The RTCP component ID, defined (as '2') in [[!RFC5245]] Section 4.1.1.1.</p></dd>
</dl>
</section>
<section id="rtcicerole*">
<h3>enum RTCIceRole</h3>
<p><dfn>RTCIceRole</dfn> contains the current role of the ICE transport.</p>
<dl class="idl" title="enum RTCIceRole">
<dt>controlling</dt>
<dd><p>controlling state</p></dd>
<dt>controlled</dt>
<dd><p>controlled state</p></dd>
</dl>
</section>
<section id="rtcicetransportstate*">
<h3>enum RTCIceTransportState</h3>
<p><dfn>RTCIceTransportState</dfn> represents the current state of the ICE transport.</p>
<dl class="idl" title="enum RTCIceTransportState">
<dt>new</dt>
<dd><p>The <code><a>RTCIceTransport</a></code> object is waiting for remote candidates to be supplied.
In this state the object can respond to incoming connectivity checks.
</p></dd>
<dt>checking</dt>
<dd><p>
The <code><a>RTCIceTransport</a></code> has received at least one remote candidate,
and a local and remote <code><a>RTCIceCandidateComplete</a></code> dictionary was not added as the last candidate.
In this state the <code><a>RTCIceTransport</a></code> is checking candidate pairs but has not yet found a
successful candidate pair, or liveness checks have failed (such as those in [[!RFC7675]]) on
a previously successful candidate pair.
</p></dd>
<dt>connected</dt>
<dd><p>The <code><a>RTCIceTransport</a></code> has received a response to an outgoing connectivity check, or has received incoming DTLS/media after
a successful response to an incoming connectivity check,
but is still checking other candidate pairs to see if there is a better connection.
In this state outgoing media is permitted.</p></dd>
<dt>completed</dt>
<dd><p>
A local and remote <code><a>RTCIceCandidateComplete</a></code> dictionary was added as the
last candidate to the <code><a>RTCIceTransport</a></code> and all appropriate candidate
pairs have been tested and at least one functioning candidate pair has been found.
</p></dd>
<dt>disconnected</dt>
<dd><p>
The <code><a>RTCIceTransport</a></code> has received at least one local and remote candidate,
and a local and remote <code><a>RTCIceCandidateComplete</a></code> dictionary was not added as the last
candidate, but all appropriate candidate pairs thus far have been tested and failed (or consent checks [[!RFC7675]],
once successful, have now failed). Other candidate pairs may become available for testing as new candidates
are trickled, and therefore the "failed" state has not been reached.
</p></dd>
<dt>closed</dt>
<dd><p>The <code><a>RTCIceTransport</a></code> has shut down and is no longer responding to STUN requests.
</p></dd>
</dl>
<div class="note">
<p>Edge Interop Note: The Microsoft Edge ORTC API implementation does not support the "failed" state, which is included in
both the WebRTC 1.0 API as well as recent drafts of the ORTC API.
One implication of this is that <code><a>RTCIceTransport</a></code> objects transition to the "closed" state under the
conditions that would normally result in a transition to "failed".
</p>
</div>
<p>The non-normative ICE state transitions are:</p>
<img alt="The non-normative ICE State Transition Diagram" src="images/msortc-corrected.png" style="width:100%" />
</section>
<section id="rtcicetransportstatechangedevent-interface-definition*">
<h3>RTCIceTransportStateChangedEvent</h3>
<p>The <code>icestatechange</code> event of the <code><a>RTCIceTransport</a></code> object uses
the <code><a>RTCIceTransportStateChangedEvent</a></code> interface.</p>
<p>Firing an
<code><a>RTCIceTransportStateChangedEvent</a></code> event named
<var>e</var> with an <code><a>RTCIceTransportState</a></code>
<var>state</var> means that an event with the name <var>e</var>,
which does not bubble (except where otherwise stated) and is not
cancelable (except where otherwise stated), and which uses the
<code>RTCIceTransportStateChangedEvent</code> interface with the
<var>state</var> attribute set to the new <code><a>RTCIceTransportState</a></code>,
<em class="rfc2119" title="MUST">MUST</em> be
created and dispatched at the given target.</p>
<dl class="idl" data-merge="RTCIceTransportStateChangedEventInit" title=
"[Constructor(DOMString type, RTCIceTransportStateChangedEventInit eventInitDict)] interface RTCIceTransportStateChangedEvent : Event">
<dt>readonly attribute RTCIceTransportState state</dt>
<dd>
<p>The <var>state</var> attribute is the new
<code><a>RTCIceTransportState</a></code>
that caused the event.
</p>
</dd>
</dl>
<dl class="idl" title=
"dictionary RTCIceTransportStateChangedEventInit : EventInit">
<dt>RTCIceTransportState? state</dt>
<dd>
<p>The <var>state</var> attribute is the new
<code><a>RTCIceTransportState</a></code>
that caused the event.
</p>
</dd>
</dl>
</section>
<section id="rtcicecandidatepair*">
<h3>dictionary RTCIceCandidatePair</h3>
<p>
The <dfn>RTCIceCandidatePair</dfn> contains the currently selected ICE candidate pair.
</p>
<dl class="idl" title="dictionary RTCIceCandidatePair">
<dt>RTCIceCandidate local</dt>
<dd><p>The local ICE candidate.</p></dd>
<dt>RTCIceCandidate remote</dt>
<dd><p>The remote ICE candidate.</p></dd>
</dl>
</section>
</section>
<section id="rtcdtlstransport*">
<h2>The RTCDtlsTransport Object</h2>
<p>
The <dfn>RTCDtlsTransport</dfn> object includes information relating to Datagram Transport Layer Security (DTLS) transport.
</p>
<section id="rtcdtlstransport-overview*">
<h3>Overview</h3>
<p>Microsoft Edge does not support the <code>getRemoteCertificates()</code> method, or a <var>state</var> value of "failed".
Since Microsoft Edge requires support for RTP/RTCP mux with DTLS, an <code><a>RTCDtlsTransport</a></code> object can only be
constructed from an RTP <code><a>RTCIceTransport</a></code> object.
</p>
</section>
<section id="rtcdtlstransport-operation*">
<h3>Operation</h3>
<p>A <code><a>RTCDtlsTransport</a></code> instance is constructed using an <code><a>RTCIceTransport</a></code> object.
<p>A newly constructed <code><a>RTCDtlsTransport</a></code>
<em class="rfc2119" title="MUST">MUST</em> listen and respond to incoming DTLS packets before <code>start()</code> is called.
However, to complete the negotiation it is necessary to verify the remote fingerprint,
which is dependent on <var>remoteParameters</var>, passed to <code>start()</code>.
After the DTLS handshake exchange completes (but before the remote fingerprint is verified)
incoming media packets may be received. A modest buffer <em class="rfc2119" title="MUST">MUST</em> be provided to avoid loss of
media prior to remote fingerprint validation (which can begin after <code>start()</code> is called).
</p>
<p>If an attempt is made to construct a <code><a>RTCDtlsTransport</a></code> instance from an <code><a>RTCIceTransport</a></code> in the "closed" state,
an <code>InvalidStateError</code> exception is thrown.
Since the Datagram Transport Layer Security (DTLS) negotiation occurs between transport endpoints determined via ICE, implementations of this specification
<em class="rfc2119" title="MUST">MUST</em> support multiplexing of STUN, TURN, DTLS and RTP and RTCP.
This multiplexing, originally described in [[!RFC5764]] Section 5.1.2, is being revised in [[RFC7983]].
</p>
</section>
<section id="rtcdtlstransport-interface-definition*">
<h3>Interface Definition</h3>
<dl class="idl" title="[Constructor(RTCIceTransport transport)] interface RTCDtlsTransport : RTCStatsProvider">
<dt>readonly attribute RTCIceTransport transport</dt>
<dd><p>The associated <code><a>RTCIceTransport</a></code> instance.
</p></dd>
<dt>readonly attribute RTCDtlsTransportState state</dt>
<dd><p>The current state of the DTLS transport.</p></dd>
<dt>RTCDtlsParameters getLocalParameters()</dt>
<dd><p>Obtain the DTLS parameters of the local <code><a>RTCDtlsTransport</a></code>.
</p></dd>
<dt>RTCDtlsParameters? getRemoteParameters()</dt>
<dd><p>Obtain the current DTLS parameters of the remote <code><a>RTCDtlsTransport</a></code>.
</p></dd>
<dt>void start(RTCDtlsParameters remoteParameters)</dt>
<dd><p>Start DTLS transport negotiation with the parameters of the remote DTLS transport, including verification
of the remote fingerprint,
then once the DTLS transport session is established, negotiate a <dfn>DTLS-SRTP</dfn> [[!RFC5764]] session to
establish keys so as protect media using SRTP [[!RFC3711]].
Since symmetric RTP [[!RFC4961]] is utilized, the <a>DTLS-SRTP</a> session is bi-directional.
</p><p>If <var>remoteParameters</var> is invalid, throw
an <code>InvalidParameters</code> exception. If <code>start()</code> is called
after a previous <code>start()</code> call, or if <var>state</var> is "closed",
throw an <code>InvalidStateError</code> exception.
Only a single DTLS transport can be multiplexed over an ICE transport.
Therefore if a <code><a>RTCDtlsTransport</a></code> object <var>dtlsTransportB</var> is constructed with an <code><a>RTCIceTransport</a></code>
object <var>iceTransport</var> previously used to construct another <code><a>RTCDtlsTransport</a></code> object
<var>dtlsTransportA</var>, then if <code>dtlsTransportB.start()</code> is called prior to having called <code>dtlsTransportA.stop()</code>,
then throw an <code>InvalidStateError</code> exception.
</p>
</dd>
<dt>void stop()</dt>
<dd><p>Stops and closes the DTLS transport object.
Calling <code>stop()</code> when <var>state</var> is "closed" has no effect.
</p>
</dd>
<dt>attribute EventHandler? ondtlsstatechange</dt>
<dd><p>This event handler, of event handler type <code><a>dtlsstatechange</a></code>,
uses the <code><a>RTCDtlsTransportStateChangedEvent</a></code> interface.
It <em class="rfc2119" title="MUST">MUST</em> be supported by
all objects implementing the <code><a>RTCDtlsTransport</a></code> interface.
It is called any time the <code>RTCDtlsTransportState</code> changes.
</p>
</dd>
<dt>attribute EventHandler? onerror</dt>
<dd><p>This event handler, of event handler type <code>error</code>,
<em class="rfc2119" title="MUST">MUST</em> be supported by all objects implementing the <code><a>RTCDtlsTransport</a></code> interface.
This event <em class="rfc2119" title="MUST">MUST</em> be fired on reception of a DTLS alert.
</p>
</dd>
</dl>
</section>
<section id="rtcdtlsparameters*">
<h3>The RTCDtlsParameters Object</h3>
<p>
The <dfn>RTCDtlsParameters</dfn> object includes information relating to DTLS configuration.
</p>
<dl class="idl" title="dictionary RTCDtlsParameters">
<dt>RTCDtlsRole role="auto"</dt>
<dd><p>The DTLS role, with a default of auto.</p></dd>
<dt>sequence<RTCDtlsFingerprint> fingerprints</dt>
<dd><p>Sequence of fingerprints.</p></dd>
</dl>
</section>
<section id="rtcdtlsfingerprint*">
<h3>The RTCDtlsFingerprint Object</h3>
<p>
The <dfn>RTCDtlsFingerprint</dfn> object includes the hash function algorithm and certificate fingerprint as described in [[!RFC4572]].
</p>
<dl class="idl" title="dictionary RTCDtlsFingerprint">
<dt>DOMString algorithm</dt>
<dd><p>One of the the hash function algorithms defined in the 'Hash function Textual Names' registry, initially specified in [[!RFC4572]] Section 8.</p></dd>
<dt>DOMString value</dt>
<dd><p>The value of the certificate fingerprint in lowercase hex string as expressed utilizing the syntax of 'fingerprint' in [[!RFC4572]] Section 5.</p></dd>
</dl>
</section>
<section id="rtcdtlsrole*">
<h3>enum RTCDtlsRole</h3>
<p><dfn>RTCDtlsRole</dfn> indicates the role of the DTLS transport.
</p>
<dl class="idl" title="enum RTCDtlsRole">
<dt>auto</dt>
<dd><p><code><a>RTCDtlsRole</a></code> is determined based on the resolved ICE role: the
"controlled" role acts as the DTLS client and
the "controlling" role acts as the DTLS server. Since <code><a>RTCDtlsRole</a></code>
is initialized to "auto" on construction of an <code><a>RTCDtlsTransport</a></code> object,
<code>getLocalParameters().role</code> will always return "auto".
</p></dd>
<dt>client</dt>
<dd><p>The DTLS client role.</p></dd>
<dt>server</dt>
<dd><p>The DTLS server role.</p></dd>
</dl>
</section>
<section id="rtcdtlsinfo">
<h3>DTLS role determination</h3>
<p>To diagnose DTLS role issues, an application may wish to determine
the desired and actual DTLS role of an <code><a>RTCDtlsTransport</a></code>.
In Edge ORTC, a <code><a>RTCDtlsTransport</a></code>
object assumes a DTLS role of <code>auto</code> upon construction.
This implies that the DTLS role is determined by the ICE role. Since
<code>getLocalParameters().role</code> always returns the role assigned
to an <code><a>RTCDtlsTransport</a></code> object upon construction
(<code>auto</code> for Edge), the <code>getLocalParameters</code>
method cannot be used to determine the desired or actual role of an
<code><a>RTCDtlsTransport</a></code>.</p>
<p>An application can determine the
desired role of an <code><a>RTCDtlsTransport</a></code> from the value of
<code><var>remoteParameters</var>.role</code> passed to
<code><a>RTCDtlsTransport</a>.start(<var>remoteParameters</var>)</code>.
If <code><var>remoteParameters</var>.role</code> is <code>server</code>
then the desired role of the <code><a>RTCDtlsTransport</a></code>
is <code>client</code>. If <code><var>remoteParameters</var>.role</code>