Basic, Windows Auth and Formfill all require that the entire back-end application is proxied, which generates the majority of web traffic, as effectively CAM is serving up the web application to the user, which results in traffic from the application to CAM and then on to the end user.
SAML, WS-fed and Oauth/openID use federation which does not require the application to be proxied, and so traffic with CAM is minimized to only authentications which use a much lower level of traffic.
