refined-airport-68974
02/19/2026, 6:47 AMtall-airline-16756
02/19/2026, 6:48 AMtall-airline-16756
02/19/2026, 6:48 AMe2e_latency means in that log line.
In this log, e2e_latency stands for “end-to-end latency.” It measures the total elapsed time for the voice-agent round trip: from when the user finished speaking (stopped_speaking_at) to when the agent’s response was produced/delivered. In your log the value is 14.271479606628418 seconds, so the full round trip took about 14.27 seconds.
What the metric normally includes
• End-of-utterance detection and any queuing delay after the user stops speaking.
• Speech-to-text (STT) processing time (if applicable).
• Language model (LLM) processing and response generation time.
• Text-to-speech (TTS) generation and any streaming/playback time.
• Network or system delays between components.
Why this matters
• Shorter e2e latency makes conversations feel natural. Typical goals are in the 2–3 second range for interactive voice agents; 14+ seconds indicates something is slowing the pipeline (long generation, slow TTS, network delays, or extra processing).
Helpful next steps to diagnose the cause
• Check the individual timing fields you already have:
◦ llm_node_ttft (Time To First Token from the LLM)
◦ tts_node_ttfb (Time To First Byte from the TTS engine)
Compare those to e2e_latency to see which stage is contributing most time.
• Look for additional timestamps such as when the request was sent to the LLM, when the LLM finished, and when TTS finished/started playback.
• If you’d like, share the other related timestamps or the full metric block and I can help pinpoint which stage is the largest contributor. Sources: Streamline troubleshooting with Agent Observability | examples/frontdesk | livekit/livekit_composite | DeepWiki