We have a big and beefy ISA Server (Web Proxy only)running on W2K SP3. This server performs very well for http traffic but seems to struggle with https. I have done some testing and have proved categorically that the proxy is indeed the bottleneck. The testing was over various client platforms (W2K, W95, NT, etc with IE5.5 SP2, IE6 SP1, etc) and noticed the same lack luster performance across all machines. If you bypass the proxy to these same sites performance is greatly increased. https in configured for 443 (default) and http on 80. Any help would be greatly appreciated. mailto:simon.marsh@xxxxxx