webrtc p2p

### WebRTC P2P Communication Implementation and Mechanism

WebRTC enables direct media-rich communication between two peers through a peer-to-peer (P2P) topology[^1]. Within this framework, WebRTC operates inside the user’s browser without requiring any additional software installation.

The core components involved in establishing and maintaining P2P connections include:

#### Signaling Process
Before actual data transmission occurs, an essential phase known as signaling takes place. During this stage, both parties exchange metadata necessary for setting up the call. This information includes session descriptions that contain details about codecs, encryption keys, and network addresses required to establish a successful connection.

Once signaling completes successfully, ICE (Interactive Connectivity Establishment) candidates are gathered from each participant's environment—these describe potential ways to reach them over different networks or interfaces. STUN servers help discover public IP addresses while TURN relays can be utilized when direct connectivity fails due to restrictive NATs or firewalls.

#### Media Stream Handling
After completing these preparatory steps, real-time audio/video streams start flowing directly between participants via UDP packets encapsulated under SRTP/RTCP protocols ensuring secure transport with minimal latency overhead. For adaptive bitrate streaming scenarios especially relevant in multicast settings like live broadcasting applications; mechanisms such as TWCC extensions come into play providing congestion control features which dynamically adjust sending rates based on receiver feedback loops thus optimizing quality-of-service parameters across varying network conditions[^2].

import asyncio
from aiortc import RTCPeerConnection, RTCSessionDescription

async def connect_webrtc():
    pc = RTCPeerConnection()
    
    @pc.on("connectionstatechange")
    async def on_connection_state_change():
        print(f"Connection state is {pc.connectionState}")
        
    offer = await pc.createOffer()  # Create SDP Offer
    await pc.setLocalDescription(offer)

    answer = RTCSessionDescription(type="answer", sdp="...")  # Assume remote party sends back Answer
    await pc.setRemoteDescription(answer)

asyncio.run(connect_webrtc())