I've got the strangest issue. I'm having issues with one-way audio when calls are sent over an IPSEC tunnel (it works fine if not going over the tunnel). The endpoint behind the firewall cannot hear the outside call, but the person on the outside can hear the endpoint behind the firewall. It seemed to be an intermittent issue, but I discovered that if torch or packet sniffer is running, things work perfectly. As soon as these are stopped, it quits working immediately. Without these tools, I've not been able to get to the bottom of it since I can't get a capture when the issue is occurring.

Any ideas what's happening?

I'm running CCR1016-12G hardware setup in HA (https://github.com/svlsResearch/ha-mikrotik) and am running v6.45.8. I'd upgrade to a later version, but am concerned about compatibility with ha-mikrotik.

VoIP calls that don't traverse the IPSEC tunnel work perfectly fine at all times. The SIP helper has been disabled.

When running torch or packet sniffer makes problem go away, it's usually problem with too liberal fasttrack or L2HW offload configuration. But it's impossible to tell as you didn't show us the config you're running.

I was able to confirm that disabling fasttrack resolves the issue. I'll do some digging to try and get my fasttrack rule more focused.

Thanks for your assistance!