In May 2010, Google boughtGlobal IP Solutions or GIPS, aVoIP andvideoconferencing software company that had developed many components required for RTC, such as codecs and echo cancellation techniques. Google open-sourced the GIPS technology and engaged with relevant standards bodies at theIETF andW3C to ensure industry consensus.[8][9] In May 2011,Google released anopen-source project for browser-based real-time communication known as WebRTC.[10] This has been followed by ongoing work to standardize the relevantprotocols in theIETF[11] and browser APIs in the W3C.[12]
In January 2011,Ericsson Labs built the first implementation of WebRTC using a modifiedWebKit library.[13][14] In October 2011, theW3C published its first draft for the spec.[15] WebRTC milestones include the first cross-browser video call (February 2013), first cross-browser data transfers (February 2014), and as of July 2014Google Hangouts was "kind of" using WebRTC.[16]
The W3C draft API was based on preliminary work done in theWHATWG.[17] It was referred to as the ConnectionPeer API, and a pre-standards concept implementation was created atEricsson Labs.[13] The WebRTC Working Group expects this specification to evolve significantly based on:
Outcomes of ongoing exchanges in the companion RTCWEB group atIETF[18] to define the set ofprotocols that, together with this document, definereal-time communications in web browsers. While no one signaling protocol is mandated,SIP overWebSockets (RFC7118) is often used partially due to the applicability of SIP[19] to most of the envisaged communication scenarios as well as the availability of open-source software such asJsSIP.
Privacy issues that arise when exposing local capabilities and local streams
Technical discussions within the group, on implementing data channels in particular[20]
Experience gained through early experimentation
Feedback from other groups and individuals
In November 2017, the WebRTC 1.0 specification transitioned from Working Draft to Candidate Recommendation.[21]
In January 2021, the WebRTC 1.0 specification transitioned from Candidate Recommendation toRecommendation.[5]
Major components of WebRTC include severalJavaScriptAPIs:
getUserMedia acquires the audio and video media (e.g., by accessing a device's camera and microphone).[22]
RTCPeerConnection enables audio and video communication between peers. It performssignal processing,codec handling, peer-to-peer communication, security, andbandwidth management.[23]
RTCDataChannel allows bidirectional communication of arbitrary data between peers. The data is transported usingSCTP overDTLS.[24] It uses the same API asWebSockets and has very lowlatency.[25]
The WebRTC API also includes a statistics function:
getStats allows the web application to retrieve a set of statistics about WebRTC sessions. These statistics data are being described in a separate W3C document.[26]
The WebRTC API includesno provisions for signaling, that is discovering peers to connect to and determine how to establish connections among them. Applications useInteractive Connectivity Establishment for connections and are responsible for managing sessions, possibly relying on any ofSession Initiation Protocol, Extensible Messaging and Presence Protocol (XMPP),Message Queuing Telemetry Transport,Matrix, or another protocol. Signaling may depend on one or more servers.[27][28]
RFC7478 requires implementations to providePCMA/PCMU (RFC3551), Telephone Event asDTMF (RFC4733), andOpus (RFC6716)audio codecs as minimum capabilities. The PeerConnection, data channel and media capture browser APIs are detailed in the W3C specification.
W3C is developing ORTC (Object Real-Time Communications) for WebRTC.[29]
WebRTC allows browsers to stream files directly to one another, reducing or entirely removing the need for server-side file hosting.WebTorrent uses a WebRTC transport to enable peer-to-peer file sharing using theBitTorrent protocol in the browser.[30] Somefile-sharing websites use it to allow users to send files directly to one another in their browsers, although this requires the uploader to keep the tab open until the file has been downloaded.[31][32][33] A fewCDNs, such as the Microsoft-owned Peer5, use the client's bandwidth to upload media to other connected peers, enabling each peer to act as an edge server.[34][35]
Although initially developed for web browsers, WebRTC has applications for non-browser devices, including mobile platforms andIoT devices. Examples include browser-basedVoIP telephony, also called cloud phones or web phones, which allow calls to be made and received from within a web browser, replacing the requirement to download and install a softphone.[36]
WebRTC establishes a standard set of codecs which all compliant browsers are required to implement (underlined). Some browsers may also support other codecs.[42]
In January 2015,TorrentFreak reported a serious security flaw in browsers supporting WebRTC, that compromised the security ofVPN tunnels by exposing a user's trueIP address.[44] The IP address read requests are not visible in the browser's developer console, and they are not blocked by mostad blocking,privacy andsecurity add-ons, enabling online tracking despite precautions.[45]
It has been reported that the cause of the address leak is not a bug that can be patched, but is foundational to the way WebRTC operates; however, there are several solutions to mitigate the problem. WebRTC leakage can be tested for, and solutions are offered for most browsers.[46] WebRTC can be disabled, if not required, in most browsers. TheuBlock Origin add-on can fix this problem (as some browsers now fix this problem by themselves, from uBlock Origin v1.38 onwards this option has been disabled on these browsers[47]).
^Jesup, Randell; Loreto, Salvatore; Tüxen, Michael (January 2021)."RFC 8831 - WebRTC Data Channels".datatracker.ietf.org.Archived from the original on 2022-03-10. Retrieved2022-03-10.
