NDI (Network Device Interface)

What it is

NDI (Network Device Interface) is a royalty-free but proprietary IP transport for broadcast-quality video, multi-channel audio, and metadata over Gigabit Ethernet. Announced by NewTek (now part of Vizrt) in 2015 and first released in 2016, NDI is widely used as a software replacement for SDI cabling in studios, production galleries, conference rooms, and — increasingly — control rooms.

How it works

Each NDI source advertises itself on the local network via mDNS/Bonjour. Receivers discover the source and pull the stream over reliable UDP (RUDP), the default transport since NDI 5; the original TCP transport remains available, and multicast can be enabled for one-to-many delivery. Full-bandwidth NDI uses adaptive intra-frame compression (~125 Mbps for 1080p60); NDI HX adds H.264/H.265 modes for tighter pipes (about 11–16 Mbps for HX2 and 50–62 Mbps for HX3 at 1080p60). End-to-end latency is in the 1–4 frame range — low enough for live switching.

Why it matters in video walls

Capturing camera feeds, second-screen conferencing, or any local app as an NDI source lets the wall display them like any other window — no capture cards, no SDI cabling, no per-source matrix routing. See video wall and AV over IP for the broader context.

Common pitfalls

• mDNS discovery is single-subnet; for multi-subnet deployments enable NDI Discovery Server.
• Full-bandwidth NDI saturates a 1 GbE port at ~6 streams — plan switch uplinks accordingly.
• IGMP snooping must be configured on switches if multicast NDI is used, otherwise the entire VLAN floods.

Related terms

• Video wall
• AV over IP
• Multiviewer