PeerConnection

PeerConnection refers to the core component of WebRTC (Web Real-Time Communication) that enables direct, peer-to-peer communication between two web browsers or applications. This communication typically involves exchanging real-time audio and video streams, as well as arbitrary data. The PeerConnection API provides a standardized way to establish and manage these connections without requiring a dedicated server for media transfer, although servers are often used for signaling and NAT traversal.

Establishing a PeerConnection involves several key steps. First, each peer creates a RTCPeerConnection object. Then, they exchange network information, such as IP addresses and port numbers, which is facilitated by a signaling mechanism. This signaling process also involves exchanging session descriptions that define the media formats and codecs to be used. Once the network information and session descriptions are exchanged, the peers attempt to establish a direct connection. This often requires the use of techniques like STUN (Session Traversal Utilities for NAT) and TURN (Traversal Using Relays around NAT) servers to overcome network address translation (NAT) and firewall challenges.

When a PeerConnection is successfully established, it allows for the bidirectional transmission of media and data. The API provides methods to add audio and video tracks, send data channels, and handle events related to connection state changes, such as ICE gathering completion and connection state updates. The PeerConnection is a crucial element for building interactive real-time applications like video conferencing, online gaming, and collaborative editing tools.