Jason Livingood: "This is a web notification system that presents an overlay service message for non-TLS sessions. Documented in RFC 6108 & in place for many years - https://tools.ietf.org/html/rfc6108 . In this case the alert informs customer of need to upgrade an end of life device."
https://tools.ietf.org/html/rfc6108 Comcast's Web Notification System Design
Yeah, cuz we're all supposed to know about rfc6108.. Guess I have some catching up to do on "Internet Engineering".