NDI Protocol: What It Is and How It Works for Live Streaming
By Dacast Editorial Team | Reviewed by Jon Whitehead, COO at Dacast | Updated May 2026
NDI (Network Device Interface) is transforming video production by making it possible to transmit high-definition, low-latency video over standard IP networks, replacing expensive SDI cabling with the ethernet infrastructure most facilities already have in place.
In this guide, we cover everything broadcasters need to know about the NDI protocol: how it works technically, what makes it different from other streaming protocols, and how to implement it in a live production environment.
Table of Contents
- What is the NDI protocol?
- Technical Overview of NDI
- Key Features of NDI for Video Streaming
- Use Cases of NDI in Video Streaming
- NDI Implementation for Video Streaming
- NDI vs. Other Streaming Protocols
- NDI Protocol: Recent Developments and What’s Next
- FAQ
- Conclusion
What is the NDI protocol?
Network Device Interface (NDI) is a proprietary protocol developed by NewTek (now part of Vizrt Group). It enables video-capable software and hardware to communicate, deliver, and receive high-definition video over standard IP networks, including LAN and, since NDI 6.3, cloud-based transport, with minimal latency.
NDI 6.3 (released 2024) introduced native cloud transport support, allowing NDI sources to be routed across the internet without requiring VPN tunnels or NDI Bridge workarounds. This is the most significant architectural change to the protocol since its launch.
NDI is widely adopted in broadcast, live events, remote production, and AV installations. It can replace costly SDI runs and HDMI cables with standard Cat5/Cat6 ethernet, simplifying infrastructure and reducing setup costs across all production scales.
NDI’s ability to transmit high-definition video over IP networks with minimal latency makes it valuable across a wide range of production environments, from live events to remote collaboration. By leveraging existing ethernet infrastructure, it eliminates the need for dedicated SDI cabling while maintaining broadcast-quality output.
The protocol uses advanced compression techniques to minimize bandwidth while preserving video quality, making [low-latency streaming] practical on standard gigabit networks without specialized hardware.
Technical Overview of NDI
Protocol Stack and Architecture
NDI uses a proprietary codec built for real-time, high-quality video compression. The network layer relies on mDNS (Multicast DNS) for automatic device discovery and identification on a local network. NDI supports both unicast (point-to-point) and multicast (point-to-multipoint) delivery, making it adaptable to a wide range of production topologies.
Encoding and Transmission
NDI uses intra-frame compression, each frame is processed independently, which minimizes encoding latency and makes it suited for live, real-time applications. The codec is optimized for high-definition video while maintaining manageable bandwidth requirements on gigabit ethernet networks.
Bandwidth Requirements
NDI is bandwidth-intensive compared to compressed streaming protocols. A single 1080p NDI stream typically requires 100–150 Mbps on a gigabit ethernet network. NDI HX (High Efficiency) and NDI HX3 are lower-bandwidth variants designed for environments where full NDI bandwidth is impractical, these sacrifice some latency in exchange for reduced throughput.
Key Features of NDI for Video Streaming
NDI Protocol Variants at a Glance:
| Variant | Latency | Bandwidth (1080p) | Best For |
|---|---|---|---|
| NDI (Full) | ~100ms | 100–150 Mbps | Studio LAN, broadcast production |
| NDI HX / HX2 | ~200–500ms | 10–20 Mbps | Wi-Fi, limited bandwidth environments |
| NDI HX3 | ~100ms | 10–20 Mbps | Low bandwidth with near-full NDI quality |
| NDI Bridge | Variable | Internet-routed | Cross-site NDI (pre-6.3 workaround) |
Other key features include:
- Low latency transmission: NDI’s intra-frame encoding makes it suitable for real-time live switching, IFB, and interactive applications
- Bi-directional communication: Simultaneous send and receive of video and audio enables talkback, remote collaboration, and interactive production
- Scalability: Adapts from small studio setups to large multi-site productions using unicast or multicast delivery modes
- No specialized cabling: Standard Cat5/Cat6 ethernet replaces SDI and HDMI runs across the production environment
Use Cases of NDI in Video Streaming
Live video production and broadcasting: NDI enables seamless integration of cameras, graphics systems, and playback devices over ethernet. Producers can perform live switching, overlay graphics, and mix audio in real time without specialized hardware or cabling infrastructure.
Remote collaboration and video conferencing: NDI’s bi-directional communication makes it effective for remote production workflows — multiple participants in different locations can exchange high-quality video feeds over IP.
Virtual sets and augmented reality: Real-time NDI transport enables live compositing of video with virtual backgrounds and AR overlays, supporting immersive broadcast environments.
Education and e-learning: NDI’s scalability allows institutions to broadcast lectures and interactive sessions to large distributed audiences without specialized streaming infrastructure.
Esports and gaming: NDI supports low-latency capture and real-time broadcast of high-definition gameplay, critical for competitive events where timing accuracy matters.
NDI Implementation for Video Streaming
NDI-Compatible Software and Hardware
Software: OBS Studio (with NDI plugin), vMix, Wirecast, and NewTek TriCaster all support NDI natively or via plugin. These tools can ingest NDI sources and output to streaming platforms via RTMP or SRT.
Hardware: NDI encoders (Magewell Ultra Encode, Kiloview N30, Haivision KB), NDI-capable cameras, and capture cards provide hardware-based NDI input and output without a PC in the signal chain.
Network Configuration for NDI
NDI requires gigabit ethernet for full-quality streams. For multi-source environments, implement Quality of Service (QoS) to prioritize NDI traffic. Ensure all NDI devices are on the same subnet for mDNS discovery, or deploy an NDI Discovery Server for multi-subnet environments.
For a complete step-by-step guide to pushing your NDI signal to the cloud via vMix, Wirecast, OBS, or a hardware transcoder, see our How to Stream NDI to the Cloud: The Dacast Workflow Guide.
NDI vs. Other Streaming Protocols
| Protocol | Primary Use | Latency | Transport | Internet-Native |
|---|---|---|---|---|
| NDI | LAN video production | ~100ms | Ethernet / IP (LAN, cloud via 6.3) | Partial (6.3+) |
| RTMP | Streaming to CDN/platforms | 5–30s (player buffer) | TCP over internet | Yes |
| SRT | Streaming over unreliable networks | 0.5–2s | UDP over internet | Yes |
| HLS | Viewer delivery / VOD | 10–60s | HTTP / CDN | Yes |
| WebRTC | Interactive / low latency | <500ms | P2P / TURN servers | Yes |
NDI Protocol: Recent Developments and What’s Next
NDI 6.3 is the most important recent development: native cloud transport replaces the NDI Bridge workaround for cross-site and cloud routing. This aligns NDI with modern cloud-based production workflows and is actively being adopted in broadcast infrastructure globally.
Looking ahead, NDI’s integration with 5G infrastructure and cloud production platforms is expanding. The NDI codec continues to improve in compression efficiency,NDI HX3 already delivers near-full-NDI quality at dramatically lower bitrates than earlier HX variants. AI-assisted bandwidth management and automated quality optimization within NDI-compatible software are emerging features in production software.
FAQ
What is the NDI protocol?
NDI (Network Device Interface) is a software-based protocol developed by NewTek that enables real-time, high-definition video and audio transmission over standard IP networks. It is widely used in broadcast production, live events, and AV installations as a replacement for SDI cabling.
Does NDI work over the internet?
NDI was originally designed for LAN environments. NDI 6.3 introduced native cloud transport, enabling NDI sources to be routed across the internet without VPN tunnels. For CDN delivery to viewers, NDI must still be converted to RTMP or SRT at an encoder before being sent to a streaming platform.
What is the difference between NDI and RTMP?
NDI is a production protocol designed for high-quality video transport within a facility or over LAN — it is not designed for viewer delivery. RTMP is a streaming protocol designed for sending video to CDNs and platforms for viewer distribution. In a typical broadcast workflow, NDI handles the intra-facility signal path and RTMP (or SRT) handles the internet delivery leg.
What software supports NDI?
OBS Studio (with obs-ndi plugin), vMix, Wirecast, NewTek TriCaster, Premiere Pro (via plugin), and many others support NDI. On the hardware side, Magewell, Kiloview, and Haivision produce NDI-capable encoders and converters.
What is NDI 6.3 and why does it matter?
NDI 6.3 is the latest major version of the NDI protocol, introducing native cloud transport support. This eliminates the need for VPN tunnels or NDI Bridge configurations to route NDI signals between locations or to cloud-based production infrastructure. It represents the protocol’s transition from a purely LAN-based technology to a cloud-capable one.
Conclusion
NDI has established itself as the standard for IP-based video production at the facility level. With NDI 6.3 extending that capability to cloud environments, the protocol is now relevant across the full production chain, from camera to CDN.
Dacast is a professional live streaming and video hosting platform built for broadcasters, businesses, and production teams. Whether your source is NDI, RTMP, SRT, or another input, Dacast provides the ingest, transcoding, CDN delivery, and monetization infrastructure to distribute your stream to any audience, at any scale.
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