Brought to you by Akamai: http://toolbar.netcraft.com/site_report?url=-https://customer.xfinity.com
But allthough the certificate is installed property it has old technology, RC4, aboard (maybe it is also Poodle vulnerable as well).
Warnings RC4 - Your server’s encryption settings are vulnerable. This server uses the RC4 cipher algorithm which is not secure.
Here -https://customer.xfinity.com/help-and-support/internet/
they kick up an error, so you might like to chat with a Comcast representitive.
Is their service somewhat under par?
polonus