I'll help you build this web-based monitoring system using Next.js with WebRTC and WebSockets for real-time communication. Since Vercel Serverless Functions don't directly support WebSocket connections, we'll use a third-party provider for the real-time functionality 12.

Let's create a solution with:

1. A dashboard to view all connected devices
2. A client page for secondary phones to share their camera/screen
3. WebRTC for peer-to-peer media streaming
4. Pusher for WebSocket signaling

Implementation Details

This monitoring system uses WebRTC for peer-to-peer media streaming and Pusher for WebSocket signaling. Here's how it works:

1. System Architecture

• Dashboard: The main control center that displays all connected devices
• Client: Secondary phones connect here to share their camera and screen
• Signaling: Pusher handles the WebSocket communication for connection setup
• Media Streaming: WebRTC handles the actual video/audio streaming

2. Key Features

• Live Camera Streaming: Clients can share their camera feed
• Screen Sharing: Clients can share their screen
• Room-based Organization: Devices connect to specific rooms
• Responsive Design: Works on mobile and desktop devices
• Dark/Light Mode: Supports theme preferences

3. Technical Implementation

WebRTC Implementation

The WebRTCConnection class handles the peer-to-peer connections:

• Creates and manages RTCPeerConnection
• Handles ICE candidates for NAT traversal
• Manages media streams (camera, screen)
• Provides methods for creating offers/answers

Signaling with Pusher

Since Vercel Serverless Functions don't directly support WebSocket connections 12, we use Pusher as our signaling server:

• Handles authentication of connections
• Provides private channels for secure communication
• Relays signaling messages between peers

4. Security Considerations

For a production implementation, you should:

1. Add proper authentication to protect rooms
2. Implement end-to-end encryption for sensitive streams
3. Add permissions management for device access
4. Use HTTPS for all connections
5. Implement rate limiting on the signaling server

5. Deployment Instructions

To deploy this system:

1. Create a Pusher account and get your credentials

2. Add the following environment variables to your Vercel project:

   • PUSHER_APP_ID
   • PUSHER_SECRET
   • NEXT_PUBLIC_PUSHER_KEY
   • NEXT_PUBLIC_PUSHER_CLUSTER
3. Deploy to Vercel

This implementation provides a solid foundation that you can extend with additional features like recording, multiple camera support, or chat functionality.

Please make sure to add the following environment variables to your project:

Great! Now that you have the environment variables set up, let's implement the actual WebRTC functionality to make the monitoring system fully functional. I'll enhance the existing code to handle real-time connections between devices.

How the WebRTC Implementation Works

I've enhanced the monitoring system with full WebRTC functionality. Here's how it works:

1. Client Device (Secondary Phone)

When a client connects:

1. It joins a Pusher presence channel for the specified room
2. It sets up media streams (camera and/or screen sharing)

3. It handles WebRTC signaling through Pusher:

   • Receives offers from the dashboard
   • Creates and sends answers
   • Exchanges ICE candidates for connection establishment

2. Dashboard (Main Phone)

The dashboard:

1. Creates a room by joining a Pusher presence channel
2. Detects when new devices connect to the room

3. Initiates WebRTC connections with each device:

   • Creates and sends offers
   • Processes answers from clients
   • Exchanges ICE candidates
4. Displays all connected device streams in a grid or list view

3. Signaling Flow

The signaling process uses Pusher 1 as follows:

1. Dashboard and clients authenticate with the Pusher server
2. When a client connects, it notifies the room
3. The dashboard creates a WebRTC offer and sends it to the client
4. The client creates an answer and sends it back
5. Both sides exchange ICE candidates until a connection is established
6. Once connected, video/audio streams directly between peers

4. Security Considerations

The implementation includes:

• Authenticated Pusher channels (presence channels)
• Secure WebRTC connections with STUN servers for NAT traversal
• Room-based isolation of devices

Testing the System

To test this system:

1. Deploy the application to Vercel
2. Open the dashboard on your main device and create a room
3. Open the client page on secondary devices and connect to the same room
4. Enable camera and/or screen sharing on the client devices
5. View all connected devices on the dashboard

This implementation provides a solid foundation for your monitoring system. You can extend it with additional features like:

• Recording capabilities
• Chat functionality between devices
• Multiple camera support
• Advanced permissions and access control

The system uses WebRTC for direct peer-to-peer connections, which provides low-latency, high-quality video streaming without requiring the video data to pass through your server 23.