One-way audio means the call connected but the media did not flow in both directions. It is nearly always local — a permission, a device selection or a firewall — rather than a fault on the line.

Work through these in order

  1. Check the browser's microphone permission for app.hyperdial.io. A blocked microphone connects the call and sends silence.
  2. Open the dialler's audio settings and confirm the input and output devices are the headset you are actually wearing.
  3. Unplug and replug the headset, then re-select it. A headset that reconnected after a sleep often comes back as a second device.
  4. Try one call on a phone hotspot. If audio works there, the problem is the office network, not the headset.
  5. Ask IT to allow UDP 10000–20000 outbound and the STUN port 3478. A firewall that permits signalling but blocks media produces exactly this symptom.

If it still happens

Open the call in Reports → Call detail and note the call ID, then send it to support with the time and the direction of the missing audio. The call ID lets us read the media path for that specific call rather than guessing from a description.