Streaming Protocols Explained: HLS, DASH, RTMP, SRT, and WebRTC

A streaming protocol is the set of rules that governs how video moves from one point to another over the internet, either from a camera to a platform, or from a platform to a viewer. The main ones fall into two groups: ingest protocols like RTMP, RTSP, and SRT that carry the live feed from an encoder to the platform, and delivery protocols like HLS, MPEG-DASH, and WebRTC that carry the video out to viewers' devices. No single protocol does everything well, so most real streaming setups use a combination, one to get the video in and another to get it out. Lightcast accepts standard live feeds from encoders and delivers across 70,000+ global CDN nodes to Roku, Fire TV, Apple TV, iOS, Android, and web at once, as part of a platform serving 5,000+ organizations and 12,000+ branded apps.

Protocols are the plumbing of streaming. Most people never think about them, and most of the time that is fine. But understanding the handful that matter makes it much clearer why a platform is built the way it is, and what questions to ask when you evaluate one.

What is a streaming protocol?

A streaming protocol is a standardized method for sending video data across a network. It defines how the video is packaged, how it is transmitted, how the receiving end reassembles it, and how the two sides handle problems like a dropped connection. Different protocols make different tradeoffs between speed, reliability, quality, and how widely they are supported across devices. That is why there is not one universal protocol, but several, each suited to a particular job in the chain from camera to screen. For the bigger picture of how video gets delivered, see our guide on how OTT works.

What is the difference between ingest and delivery protocols?

This is the distinction that makes everything else make sense. Ingest, sometimes called the first mile or contribution, is getting the live video from the source, usually an encoder or camera, into the streaming platform. Delivery, the last mile, is getting the video from the platform out to the many viewers watching. The two jobs have different demands. Ingest is usually one strong connection that needs to be reliable and reasonably fast. Delivery is one source fanning out to thousands of varied connections and devices, which needs broad compatibility and the ability to adapt to each viewer. Because the demands differ, the protocols differ, and a platform typically speaks one set for ingest and another for delivery. The encoder sits at the ingest end, which we cover in our guide on live streaming encoders.

What are the main ingest protocols?

Three come up most often for getting a live feed into a platform.

RTMP. The long-time workhorse of ingest. RTMP is supported by nearly every encoder and streaming tool, is reasonably fast, and is the default most setups reach for. It is no longer used for playback in modern browsers, but for sending a feed up to a platform it remains everywhere.

RTSP. Common with IP cameras and surveillance-style sources. Many security and venue cameras output RTSP natively, so platforms that accept it can pull directly from that hardware.

SRT. A newer open protocol built for reliability over unpredictable networks. SRT recovers from packet loss and adds security, so it holds a stream together over a shaky internet connection where others would stutter. It has become popular for professional contribution feeds.

What are the main delivery protocols?

On the way out to viewers, a few protocols dominate.

HLS. Originally from Apple, HLS is the most widely supported delivery protocol, playing on nearly every device and browser. It breaks video into short segments and supports adaptive bitrate, which is why it is the default for reaching a broad audience. Its tradeoff is higher latency, though low-latency versions narrow that gap.

MPEG-DASH. An open, vendor-neutral standard similar in approach to HLS, also segment-based and adaptive. It is used widely across the industry, often alongside HLS so every device gets a format it understands.

WebRTC. Built for real-time, two-way communication, WebRTC delivers sub-second latency. It is the choice when interaction matters, such as live Q&A, auctions, or betting, though it scales differently than the segment-based formats built for mass audiences.

The segmenting and adaptive behavior of HLS and DASH is what we cover in our guide on adaptive bitrate streaming.

Which streaming protocol should you use?

In almost every case, more than one. A typical setup uses a reliable ingest protocol to get the feed into the platform, then delivers to viewers over HLS, and often DASH as well, so every device is covered. If near-real-time interaction is essential, WebRTC enters the picture for delivery. The practical point is that you rarely pick a single protocol. You pick a platform that speaks the right ones at each stage and handles the handoff between them for you. That is usually the better question to ask: not which protocol, but whether the platform manages all of this so you do not have to. For how platforms compare more broadly, see our streaming platform comparison.

How do protocols relate to latency and quality?

Closely. The delivery protocol is one of the biggest factors in how far behind live your stream runs. Segment-based protocols like HLS and DASH trade a little delay for stability and scale, while WebRTC trades some scale for near-real-time speed. Protocols also carry the adaptive bitrate behavior that keeps quality smooth across different connections. So when you hear about a stream being low-latency, or adjusting quality on the fly, those capabilities are riding on top of the delivery protocol in use. For the speed side of this, see our guide on low-latency live streaming, and for the reliability behind delivery, our guide on what makes streaming reliable.

How Lightcast Handles Streaming Protocols

Standard ingest from your encoder.

Lightcast accepts standard live feeds from encoders and cameras, so you can send your stream in with the tools and workflow you already use. Explore the platform on our media cloud OVP and live streaming pages.

Delivery to every device at once.

Your stream goes out to Roku, Fire TV, Apple TV, iOS, Android, and web simultaneously, in the formats each device needs, so you reach your whole audience from a single live source.

Global delivery across 70,000+ CDN nodes.

Whatever the delivery format, each viewer is served from a node near them, which is what keeps playback smooth at scale rather than straining across distance.

The protocol handoff, handled for you.

You send one feed in, and Lightcast takes care of converting and delivering it in the right formats to every screen, so you do not have to manage the protocol chain yourself.

Summary

Streaming protocols are the rules that move video from camera to platform and from platform to viewer. They split into ingest protocols like RTMP, RTSP, and SRT that bring the live feed in, and delivery protocols like HLS, MPEG-DASH, and WebRTC that send it out, with each making its own tradeoff between speed, reliability, scale, and device support. Because no single protocol is best at everything, real streaming setups combine them, and the better question is whether your platform manages the whole chain for you. Lightcast accepts standard encoder feeds and delivers to every major device across 70,000+ global CDN nodes for 5,000+ organizations and 12,000+ branded apps, and was named Fastest Deployment OTT Platform Provider 2026 by The Silicon Review. To learn more or schedule a demonstration, visit lightcast.com.