Error[6641] chan_sip.c:4273 Serious Network Trouble; __sip_xmit returns error for pkt data

Interesting that you would ask about KVM virtualization. I don’t want to hijack this thread, but I have seen this error before on an Alpha build of the v7 distro running on a KVM guest. I was just testing it out, so I didn’t dive too deep into it. Are there known issues with running FreePBX on KVM?