Resources · 5 guides
WebRTC and Networking for File Transfer
Data channels, ICE, STUN, TURN and NAT traversal, explained with the trade-offs that decide whether two peers connect.
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About this topic
WebRTC is the browser standard that makes direct browser-to-browser connections possible. For file transfer the relevant parts are the data channel (reliable, ordered messages over SCTP, encrypted with DTLS) and ICE, the procedure that tries every possible network path between two peers using STUN and TURN servers.
Most failed or slow WebRTC transfers come down to the network: NAT behaviour, blocked UDP, proxies that only speak HTTP, or a relay in the path. These guides explain the mechanisms well enough to diagnose those cases, and show where SRIFT falls back to a relay over port 443 when WebRTC cannot connect.
Guides
- How WebRTC File Transfer Works: Data Channels in PracticeWebRTC data channels explained for file transfer: SCTP over DTLS, message sizes, backpressure with bufferedAmount, ordering, and what breaks at scale.
- STUN vs TURN: How WebRTC Gets Through NATWhat STUN and TURN servers do, how ICE picks between host, server-reflexive and relay candidates, and what a TURN relay can and cannot see.
- NAT Traversal Explained for Peer-to-Peer AppsWhy devices behind NAT cannot simply connect, how UDP hole punching works, which NAT behaviours defeat it, and why relays remain necessary.
- WebRTC Behind Corporate Firewalls and ProxiesWhy WebRTC fails on locked-down networks (UDP blocked, proxies, TLS inspection) and the fallbacks that still work over outbound port 443.
- WebRTC vs WebSockets for File TransferDirect WebRTC data channels and server-relayed WebSockets compared for file transfer: latency, throughput, reliability, cost and privacy.