I've AT&T fiber (in RTP, NC) (AS7018) and I notice UDP QUIC traffic from google (esp. youtube) becomes very slow after a time. This especially occurs with ipv4 connections. I'm not the only one to notice; a web search for e.g. "Extremely Poor Youtube TV Performance" notes the issue. I assume traffic is being throttled on AT&T's side. And it's not done with their CPE; I'm bypassing their NAT box and connecting my laptop directly to the ONT. A quick google search shows people are aware that QUIC can look like DoS traffic -- but how widely known is this problem? It may become worse if / when sites transition to HTTP/3 For now I reject UDP 443 on the client firewall. Applications using QUIC client libraries then fallback to TCP. This works well and I have no issues with latency or throughput when using TCP. May I naively ask if Google staff are working with AT&T to address this? -- Dan