# Using NDI and Dante on the same Network ## Introduction Running Dante and NDI in different networks or VLANs is always the recommended choice but this sometimes requires complex network infrastructure that is not always feasible. As IP-based audio and video solutions become standard in live production and broadcast environments, a common question arises: *Can NDI and Dante coexist on the same network?* The answer is **yes**, but only under the right conditions. ## Understanding the Protocols: NDI vs Dante ### NDI (Network Device Interface) NDI is a video-over-IP protocol optimized for ease of use and versatility. Its key characteristics include: * Uses various transport methods: TCP, UDP, Multi-TCP, and R-UDP. * No centralized synchronization mechanism. * Audio and video are embedded together and rely on best-effort delivery. * Can be bandwidth-intensive, especially full-bandwidth NDI (100–300 Mbps per stream). ### Dante Audio Dante, developed by Audinate, is designed for professional, low-latency audio transport over IP. Its key characteristics include: * Ultra-low latency (typically <1 ms) * Uses PTP (Precision Time Protocol, IEEE 1588) for tight synchronization between all devices * Each audio stream is typically mono, point-to-point * Highly sensitive to jitter and network congestion ### NDI and Dante on a 1G Network: Real-World Observations **Scenario 1**: A Single Computer Running NDI and Dante A single computer (e.g., running vMix or TriCaster) receives NDI streams and handles Dante audio via the same 1G NIC. As long as it only receives NDI streams, Dante works fine. Once the computer **transmits** NDI streams, Dante experiences: * Increased latency * Audio glitches * Eventually, Dante devices may mute audio completely due to PTP sync loss #### Why does this happen? NDI video streams can flood the NIC and switch buffers. Since Dante relies on highly predictable packet timing and synchronized clocks (via PTP), any jitter or delay in network delivery, especially in PTP packets, can cause the system to desynchronize, leading to audio dropouts. **Scenario 2**: 10G Backbone with 1G Endpoint The main NDI+Dante computer is connected via 10G to a core switch. A second switch, connected via 1G uplink, serves a Dante commentary station. Everything runs smoothly until an NDI decoder is added to the second switch and starts receiving a video stream from the main computer. Suddenly, the Dante commentary position experiences PTP errors and intermittent audio mute. Replacing the second switch with a 10G model and using a 10G uplink immediately resolves the issue. #### Why does this happen? Traffic from an NDI receiver saturates the uplink. Simply having an NDI transmitter alone doesn't cause this traffic surge. NDI streams are unicast and only begin flowing when a receiver connects. When the receiver is on the 1G switch and pulls full-bandwidth NDI from the 10G host, the 1G uplink becomes a bottleneck. This bottleneck causes latency and jitter, especially affecting: * PTP clock sync packets * Time-sensitive Dante audio packets Consequently, sync is lost and Dante audio mutes. By contrast, if the NDI transmitter is on the 1G switch without an active receiver, the traffic isn't triggered, and Dante remains unaffected. ## NDI Transport Protocols and Network Behavior NDI supports multiple transport types, but not all are equally suitable in mixed environments. | Protocol | Suitable with Dante? | Notes | | --------- | -------------------- | ----------------------------------------------------------------------------------------------------- | | TCP | With care | Requires proper flow control; can introduce delay under congestion | | UDP | Better | Predictable; ideal for real-time flows | | R-UDP | Recommended | Reliable UDP; good compromise between speed and reliability | | Multi-TCP | Avoid |

Creates multiple TCP streams with independent buffers; bad for real-time sync like Dante

| \ \&#xNAN;*Flow Control must be enabled on all switches for stable coexistence.* #### Best Practices for NDI + Dante on the Same Network To make it work reliably: \ \ 1\. **Use a 10G network backbone** for any shared segments carrying both Dante and NDI. \ 2\. **Avoid Multi-TCP mode** in NDI, especially in mixed Dante environments. \ 3\. **Enable flow control** on all switch ports. \ 4\. **Use managed switches** that support IEEE 802.1p traffic prioritization (to prioritize PTP and Dante audio) \ 5\. **Monitor the Dante Clock** status and latency metrics on all endpoints. \ 6\. **Avoid 1G uplinks** where video and audio traffic are mixed. #### Conclusion NDI and Dante can coexist on the same network, but only if the network is properly designed to handle their demands. Dante's strict timing requirements make it particularly vulnerable to congestion and jitter, while NDI’s high-bandwidth nature can easily monopolize links if not carefully managed. Proper switch configuration, bandwidth planning, and protocol awareness are essential to ensure stable, high-performance operation in mixed NDI + Dante environments.