"However, one optimization that can be made for some browsers is OCSP stapling: the server can include (staple) the OCSP response from the CA to its certificate

"However, one optimization that can be made for some browsers is OCSP stapling: the server can include (staple) the OCSP response from the CA to its certificate chain, allowing the browser to skip the online check. Moving the OCSP fetch to the server allows the server to cache the signed OCSP response and save the extra request for many clients. However, there are also a few things to watch out for: OCSP responses can vary from 400 to 4,000 bytes in size. Stapling this response to your certificate chain may once again overflow your TCP congestion window—pay close attention to the total size. Only one OCSP response can be included, which may still mean that the browser will have to issue an OCSP request for other intermediate certificates, if it has not been cached already." http://chimera.labs.oreilly.com/books/1230000000545/ch04.html#_ocsp_stapling http://chimera.labs.oreilly.com/books/1230000000545/ch04.htm...