May 2026
Understanding RTMP: The Protocol Behind Live Streaming
What RTMP is, how it works, and why it powers almost every live stream.
What is RTMP?
RTMP (Real-Time Messaging Protocol) is a TCP-based protocol originally developed by Macromedia (later Adobe) for transmitting audio, video, and data between a server and a Flash player. Despite Flash being defunct, RTMP became the industry standard for live streaming ingest — used by YouTube, Twitch, Facebook, Instagram, and virtually every streaming platform today.
How RTMP Works
When you hit Start Streaming in OBS, RTMP handles the entire transport process:
- 1
OBS encodes your video and audio into an H.264/AAC stream.
- 2
The stream is packaged into RTMP chunks and sent over TCP to your RTMP ingest server (e.g. HostVortex).
- 3
The ingest server receives and validates the stream using your stream key.
- 4
The server re-distributes the stream to platforms or transcodes it for viewers at different quality levels.
RTMP vs. RTMPS
RTMPS is simply RTMP wrapped in TLS/SSL encryption — the same protocol, secured. Many platforms now require RTMPS for ingest. HostVortex supports both.
| Feature | RTMP | RTMPS |
|---|---|---|
| Encryption | None | TLS/SSL |
| Default Port | 1935 | 443 |
| Platform Support | Universal | Most modern platforms |
| Typical Use | Local/private ingest | Public platform ingest |
Key Concepts
Stream URL
The RTMP endpoint of your ingest server. For HostVortex this is provided in your dashboard.
Stream Key
A unique token that authenticates your stream to the platform. Treat it like a password — never share it publicly.
Ingest Server
The server that receives your RTMP stream from OBS. HostVortex acts as your ingest server and then forwards to all connected platforms.
RTMP and HostVortex
When you stream to HostVortex, your OBS sends a single RTMP stream to HostVortex's ingest server. HostVortex then duplicates and forwards that stream via RTMP/RTMPS to each of your connected platforms simultaneously — no extra encoding passes, no extra CPU usage on your end.
A Note on Latency
RTMP typically adds 2–5 seconds of latency from encoder to viewer. This is inherent to the protocol and the transcoding pipeline on the platform side. For most streamers, this is acceptable. Platforms like Twitch offer a Low Latency Mode which can reduce this to under 2 seconds, but this works at the platform viewer layer, not the RTMP ingest layer.
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