Great to hear you've got the 1:1 PeerJS/WebRTC setup running smoothly on your remote server! Moving to a 1:N mesh architecture for 4-5 users is totally feasible with your existing setup—here's a step-by-step breakdown to make this happen:

Core Concept: Mesh Architecture #

In a mesh setup, every participant establishes a direct peer-to-peer connection with every other participant. For 4-5 users, this is manageable (each user will have 3-4 concurrent connections) and avoids the complexity of a media server for now.

1. Extend Your NodeJS/PeerJS Server for Room Management #

First, you'll need a way to track which peers are in the same "room" so new participants know who to connect to:

• Add simple room registration logic to your existing NodeJS server. When a peer joins, they send a room ID (or use a default room), and the server stores their peer ID in that room's list.
• When a new peer joins, the server returns the list of existing peer IDs in the room.
• When a peer disconnects (listen for disconnect events from the PeerJS server), remove their ID from the room list and notify all remaining peers to clean up connections.

2. Update Client-Side Logic for Multi-Peer Connections #

On the client side, modify your code to handle multiple incoming/outgoing calls:

• When joining a room: After getting the list of existing peers from your server, loop through each peer ID and initiate a call with peer.call(remotePeerId, localMediaStream).
• Handle incoming calls: Keep listening for the call event on your Peer instance. When a call comes in, answer it with call.answer(localMediaStream)—this sends your stream to the caller and starts receiving theirs.
• Display remote streams: For every incoming stream (via call.on('stream', (remoteStream) => { ... })), create a new <video> element, set its srcObject to remoteStream, and add it to your UI. Don't forget to set autoplay and playsinline for smooth playback.

3. Manage Peer Disconnections #

To keep your UI clean and connections healthy:

• Listen for the close event on each call instance. When a peer disconnects, remove their corresponding <video> element from the page and update your local list of active peers.
• If your server notifies you of a peer leaving, you can also proactively close any connections to that peer.

4. Optimize for 4-5 Participants #

Mesh works well for small groups, but a few tweaks will keep performance smooth:

• Limit video resolution (e.g., 640x480 or 720p) using getUserMedia constraints:

  const constraints = {
    video: { width: 640, height: 480, frameRate: 30 },
    audio: true
  };
  navigator.mediaDevices.getUserMedia(constraints);
  

• Disable unnecessary audio processing (like echo cancellation if you're using headsets) to reduce CPU load.
• Monitor bandwidth with RTCPeerConnection.getStats() and adjust stream quality dynamically if needed.

5. Prep for Future Media Server Migration #

Since you plan to move to a media server later, keep your code modular now:

• Separate room management logic from media stream handling. For example, create a RoomManager class that handles joining/leaving rooms and getting peer lists—later, you can swap this out for calls to a media server's API (like Janus or Mediasoup).
• Keep your stream rendering logic generic: as long as you're handling MediaStream objects, switching to a server-provided stream will require minimal changes.

That's it! With these changes, you'll have a working 4-5 person mesh-based video call. Once you need to scale beyond 10 users, migrating to an SFU-based media server will be the next logical step—those servers handle the heavy lifting of stream forwarding, so each client only sends one stream instead of multiple.

内容的提问来源于stack exchange，提问作者John G