One way audio issues, or no audio at all.

If you experience calls with one-way audio, or no audio at all, here are some possible causes and solutions.

- Check the MUTE button if your phone has one.
- If this is a new phone, make sure the handset is plugged into the correct handset jack, NOT the headset jack.
- If this is something that was working, but recently stopped, try rebooting your router and voip device (one at a time, not both).

It is also possible that your network or phone is misconfigured.  Here's how it happens...

Every VoIP call uses 3 ports that must traverse your network firewall.

1. SIP Signal Port
2. RTP Inbound Audio Port
3. RTP Outbound Audio Port

So if you have audio in, but remote party cannot hear you, or vice versa, it may be that one of the audio stream ports is getting blocked.

To resolve, try the following...

- See if your router has a SIP ALG feature.  If so, experiment with Enabling or Disabling it.
- Log into your firewall/router and forward RTP audio port range 10000 to 65000 (UDP Only) to your voip device's LAN IP address.
- See if your voip device has a NAT or STUN setting. If so, try enabling one of both of those features (they may be one and the same).

If none of the above helps, please open a Support Ticket for further assistance.


  • audio, router, firewall, port, forwarding
  • 29 Users Found This Useful
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