The phone rings, but there's no audio if you're using VPN or the Sophos Connect client
Condition
You're able to place a call and the receiving phone rings, but you don't hear any audio.
Cause
This condition occurs if the caller can't send data at the RTP stage of a SIP connection. Here's an example of this condition where Alice is the caller and Boris is the recipient.
Remedy
- Go to Rules and policies > Firewall rules.
- Make sure you've configured a firewall rule for SIP.
- Make sure you select the recipient's network in Destination networks. If you want to call any phone, set the recipient's network to Any.