I have a customer who is attempting video playback via HTTP progressive download of very large files ( 1 GB). There is no problem once a file is cached at the edge via my CDN, but hits to my origin (first hits prior to edge-cache population) experience stalling and loss of sync between audio and video about an hour and a half into playback. This occurs pretty reliably at that point, suggesting that some threshold somehwere is getting hit. Are there IIS configuration knobs governing HTTP Response size? Other data points: I am unable to replicate this problem. I am looking at client bandwidth and last mile issues. I am looking at possible encoding recipe dependencies. But this problem never came up when we were using a "push" cache configuration (CDN-hosted origin), so something funky serverside at my origin seems like a likely culprit. Thanks ...