HTTP client, SSL and CRL check

We recently experienced a severe spike in latency of our one applications that uses HttpWebRequest to connect to a remote service over SSL under high load. After looking at it from a lot of angles, the thought of the certificate verification being blocked seemed like a possible cause, especially since the application is hosted in a locked-down DMZ and only the necessary minimum access granted to access the service URL. Once we granted access to be able to perform the OCSP and/or CRL checks, transactions started flowing immediately. I found this article at the time explaining the whole process. I also think a contributing factor was that only two active HTTP requests are allowed to a destination at once by default according to RFC 2616, my guess is that the CryptoAPI would adhere to this same limit, so all OCSP/CRL requests queued until the active ones timed out.