We have a collocated web server running Windows Server 2003 SBS. The provider has provisioned 100Mbps for our use. The provider has said there are no concurrent connection, or session bandwidth limits on their router to our server.
The office I'm working from has Comcast 50Mbps down 10Mbps up. I can only get at max 1.5MB/s (roughly 12Mbps) on a single connection. However, when running two concurrent downloads from our collocated server, both downloads run at 1.5MB/s. I've messed with the GlobalMaxTcpWindowSize, and Tcp1323Opts registry keys to enable window scaling negotiation per tcp session, on both the client and server. However haven't noticed any difference... and I've confirmed with wireshark that window scaling is in effect.
an interesting note.... I can only achieve the 1.5MB/s when using a Linux client, windows clients typically see between 275KB/s-800KB/s. Downloads from other sites (such as nvidia.com drivers) come in at full speed regardless of what client OS we use.
I've tried downloading from home on another 30down/10up connection and have the same results with windows clients....