From youtube.com to the first video frame

From youtube.com to the first video frame A sequence diagram generated by Archify. type youtube.com and press Enter resolve youtube.com return an address or cached answer open QUIC + TLS 1.3, or TCP + TLS verify certificate; encrypted channel ready GET / over HTTPS serve cached response or route request HTML plus page data 200 response in packets request CSS, JavaScript, images and APIs parse, layout, paint the page choose a video request playback manifest and first segments send audio and video chunks at a suitable quality decode, buffer and show the first frame Find the destination Create a secure connection Load and render the page Start adaptive video playback You · address bar and screen · Sequence participant You address bar and screen Browser · network and render · Sequence participant Browser network and render DNS · name resolution · Sequence participant DNS name resolution Edge · nearby HTTPS endpoint · Sequence participant Edge nearby HTTPS endpoint Web service · page and API responses · Sequence participant Web service page and API responses Media delivery · manifest and video segments · Sequence participant Media delivery manifest and video segments Legend main request return security async trace message