SFU vs. MCU vs. Mesh: Choosing the Right WebRTC Architecture for Scale

The first architectural decision in a WebRTC project is topology. This guide compares mesh, MCU, and SFU across bandwidth, CPU, latency, and scalability. It includes practical thresholds: mesh typically fails beyond 4 participants due to upload bandwidth exhaustion, while MCU server CPU limits often cap concurrent publishers at 20–30 per node. SFU routing is explained as the scalable middle ground, with guidance on when to use hybrid topologies that switch from P2P to SFU dynamically as participant count grows.