In a message written on Tue, Mar 27, 2007 at 02:41:13PM -0700, Philip Lavine wrote:
This is the exact issue. I can only get between 5-7 Mbps. So the question is really what incremental performance gain do WAN accelerators/optimizers offer? Can registry/OS tweaks really make a significant difference because so far with all the "speed enhancements" I have deployed to the registry based on the some of the aforementioned sites I have seen no improvement.
In short, yes. Working for an ISP with colos on both coasts I helped customers on numerous occasions "tune" their operating system. A plain jane desktop from choose your favorite vendor today will do ~300-~500Mbps/sec of FTP with only minor tuning assuming you have good disks (e.g. not a laptop). Most servers can be easily tuned to chew a full gigabit. TCP Window Scale, Selective Acknowledgement, and a "TCP Send" and "TCP Receive" buffers that are big enough to handle your bandwidth*delay product (*2 for a good margin) are all that's required. Jumbo frames are not, and in fact make little difference. All of the TCP limits are 100% the same with Jumbo frames, and most NIC's generate roughly the same number of Interrupts with Jumbo frames enabled. You're saving a little bit of IP processing overhead on the end hosts, but I doubt you'll measure it. Wan optimizers are extremely complex points of failure that generally mess with the protocol in ways that are extremely dangerous, they should only be used if you don't have direct access to the end boxes to fix them. Google can turn up 50 write ups on how to tune your settings better than I could ever write here. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org