I am evaluating Proxmox 8.4 as a replacement for a number of ESX/i based servers. As part of my testing, I have SBC's sending messages to a Linux Kamailio server. When I run a test server on Proxmox, there is is a very large performance degradation compared to ESX/i. I have finally gotten to the point that I see a SIP INVITE arriving on the server, but apparently sitting somewhere in a queue and Kamailio not seeing the INVITE until hundreds of milliseconds later. This Kamailio server is Ubuntu 22.04, and the Proxmox config uses a VirtIO network interface, but I have also tried an Intel e1000E but did not notice much difference. CPU is native ("host" type), and during the test, CPU load was insignificant. Any ideas where I should look for a bottleneck?