SRTLA vs RTMP vs SRT: Which Protocol for Mobile Streaming?

Protocol confusion costs streamers real drops. RTMP, SRT and SRTLA solve different problems, and knowing which does what tells you exactly where each belongs in your chain — from your phone to the platform.

RTMP: the universal last mile

Two decades old and still everywhere because Twitch, YouTube and Kick accept it natively. But RTMP runs over TCP: any packet loss stalls the whole stream while TCP retransmits, latency creeps up, and there's no concept of multiple links. Fine on stable fiber; brittle on a moving phone.

SRT: loss recovery done right

SRT moves streaming to UDP and adds encryption, retransmission (ARQ) and configurable latency buffers. Lost packets are recovered within the buffer window instead of freezing the connection. One link though — SRT doesn't care if you have four radios; it rides whichever route your OS picked.

SRTLA: SRT plus link aggregation

SRTLA takes SRT and spreads its packets across every available connection at once, acknowledging per-link delivery. Weak link? Its share shrinks automatically. Connection dies? The others never notice. This is the protocol that makes walking streams possible — and it requires a receiver that speaks it: a relay or server designed for SRTLA.

Side by side

• ▸Loss behavior: RTMP stalls · SRT retransmits within buffer · SRTLA retransmits across bonded links
• ▸Multiple connections: RTMP no · SRT no · SRTLA yes, by design
• ▸Typical added latency: RTMP variable and creeping · SRT 1–4s tunable · SRTLA similar with bonding overhead
• ▸Platform support: RTMP universal · SRT/SRTLA needs a receiver that converts
• ▸Battery cost on phones: highest with RTMP stalls and retries, lowest with clean SRTLA bonding

So which goes where?

Phone sends SRTLA to your relay (bonding handles the hostile part of the journey). The relay delivers SRT or RTMP into OBS (stable local or datacenter network). OBS pushes RTMP to platforms. Each protocol does the job it was built for, and the chain stays solid end to end.