Significant delay when sending RTP audio via Ingress

[fabiogambaaik]

Hi,

I have a .NET application that receives an RTP audio stream in PCM mulaw format (8000 Hz).
My goal is to send this audio stream into a LiveKit room using a Ingress.

Steps performed

1. Successfully created an Ingress via the LiveKit API.
2. Used FFmpeg to send the RTP audio stream to the Ingress endpoint with the following command:

ffmpeg -fflags nobuffer -flags low_delay -f mulaw -ar 8000 -ac 1 -i pipe:0 -c:a aac -b:a 24k -f flv {rtmpUrl}

where {rtmpUrl} is the URL returned by the Ingress creation.

Issue

FFmpeg connects successfully to the Ingress endpoint.

However, there is a delay of approximately 10-15 seconds between sending the audio to the Ingress and hearing it inside the room.

This delay occurs both when running the setup locally and when using LiveKit’s cloud service.

By comparison, when sending the same RTP stream to a standard RTMP server running on Docker and playing the stream, the delay is at max 1 second.

Environment

Using the latest LiveKit server and Ingress Docker images.

The stream is raw RTP PCM mulaw 8000 Hz.

[itamayo]

RTMP streaming typically introduces roughly 2-20,
use WHIP to get (ms) delay