The difference between RTMP, SRT and SRTLA
You want to know which protocol actually keeps you live when your connection is not perfect. RTMP, SRT and SRTLA all do the same basic job, carrying your stream from your device to a platform, but they cope very differently with a shaky signal. Super Simple IRL streams over SRT, or its own bonding transport SSTL when you are combining connections, so you never have to pick. Here is each one, and when to use it.
Side by side
| RTMP | SRT | SRTLA | SSTL | |
|---|---|---|---|---|
| Built for | Stable, wired links | One shaky link | Several links at once | Several links at once, on a phone |
| Recovers lost pieces | No | Yes, re-sends them | Yes, re-sends them | Yes, and faster after a sudden burst of loss |
| Survives one network dying | No | No | Yes | Yes |
| Typical home | Home broadband to Twitch | One SIM on the move | Backpack rigs and encoder boxes | Super Simple IRL |
| What you configure | URL and stream key | URL, key and a latency value | A relay you rent or run | Nothing |
For IRL streaming the answer is the right-hand column: bonding, combining every connection you have into one steady stream. What is SSTL explains how ours works and why owning both ends of the connection lets it react faster.
RTMP: the classic
RTMP is the long-standing way to go live. It is what most people use to stream to Twitch or YouTube from a computer, and nearly everything supports it.
Its weakness is that it was built for stable, wired connections. It has no real way to recover when pieces of your video go missing. At home that almost never happens, so RTMP is great. On mobile data, where the signal comes and goes, it stutters and drops.
See what is RTMP for the full picture.
SRT: built for shaky connections
SRT was designed for the messy, real-world connections that RTMP hates. When pieces of your stream go missing, SRT quietly re-sends them fast enough that your viewers never notice. That is what lets it hold up over mobile data.
The catch is that SRT still uses a single connection. It is reliable, but if that one connection hits a really bad patch, the stream feels it.
See what is SRT for more.
SRTLA: SRT with a safety net
SRTLA (SRT Link Aggregation) is SRT that can use several connections at the same time. It spreads your stream across everything you have, such as mobile data and Wi-Fi, or the several modems in a backpack rig, and combines them into one steady stream. If one connection drops, the others carry on without a gap. It is the well-known, off-the-shelf way people have bonded SRT streams for years.
Where it struggles is recovering quickly from a sudden burst of packet loss, which is the normal failure of a phone walking past a building, and it does not do much beyond the basic combining. It also needs a receiver at the other end, which is the relay most bonded setups rent or run.
Super Simple IRL does not use SRTLA. We built our own bonding transport, SSTL, from scratch, purpose-built to recover from packet loss faster and to do more, while the managed cloud takes the heavy lifting off your phone.
See what is SRTLA and what is bonding for how the combining works.
If you already own a rig
Worth saying plainly, because it decides whether this app is for you. Super Simple IRL streams to one locked destination: our managed cloud. There is no field to paste an SRT URL into, no way to point it at a relay you already rent, and no local OBS in the chain. Your encoder box and your relay do not plug into this.
That is a deliberate trade. You give up the freedom to run your own transport end to end, and in exchange the bonding, the receiver, the compositing and the restream to your platform are one subscription at £50 a month and nothing to configure at my.ssirl.com. If running your own stack is the part you enjoy, keep your rig. If it is the part you tolerate, this replaces it.
Which one is right for you
- Streaming from home on broadband? RTMP is simple and fine.
- Out with a single SIM or hotspot? SRT will hold up far better than RTMP.
- Out and want the steadiest possible stream? Bonding. Super Simple IRL delivers that with SSTL, not SRTLA.
The app can also take an RTMP feed in from a wireless action camera, so the gear you already own keeps working while the outbound stream uses a transport built for the real world.
Frequently asked questions
What is the difference between RTMP, SRT and SRTLA?
RTMP is the classic protocol used to go live on Twitch and YouTube, and it is great on a stable connection. SRT is built to survive shaky connections, so it holds up over mobile data. SRTLA is SRT that can use several connections at once, so if one network drops, the others keep you live.
Which one should I use for IRL streaming?
Bonding. IRL streaming happens over mobile data while you move, which is exactly where RTMP falls over. SRTLA is the well-known, off-the-shelf way to bond several connections, but Super Simple IRL does not use it. We built our own bonding transport from scratch, SSTL, which recovers from sudden packet loss faster and does more, so if one network hits a dead spot, the others keep you live.
Is RTMP still worth using?
Yes, on a stable connection. Streaming from home over broadband, RTMP is simple and works everywhere. Many cameras also output RTMP, and Super Simple IRL can take that feed in from a GoPro or DJI.
Can I point Super Simple IRL at my own SRT server or relay?
No. The app streams to SSIRL's managed cloud on a locked destination, so there is no SRT URL field and no relay to rent or run. If you already own an encoder box and a relay, this app replaces them rather than joining them.