If the equipment does connection tracking for TCP, then it most certainly does for UDP. Raw UDP does not have the notion of stream, but it most certainly does h

If the equipment does connection tracking for TCP, then it most certainly does for UDP. Raw UDP does not have the notion of stream, but it most certainly does have flows. If the equipment does it for TCP, id does it for UDP. However most routers don't do connection tracking at all. That is way too expensive at scale for zero benefits. Take your transit provider, it has tens of terabits of data per second, and those can be handled by a single router. That's a buttload of different stream for a single device, and connection tracking is expensive to do. I can say for experience that connection tracking tables for a single hypervisor with VMs can reach gigabytes. For a single node. Now extrapolate that to a backbone router. It's not happening.