Hi, Am running SIPP on a pretty fresh default install of FS and am only getting 3 calls processed per second when put under load. I see others are getting in the region of 100 calls per second, so am guessing my config has something suspect? And not just a 'tuning' issue as the difference is huge. CPU usage is <3% and hard disk sounds very active (however a 10ms operation every 200ms would sound busy to a human). So puzzles me why it is taking so long. My scenario is the SIPP provided UAC pointed to extension 3000 (the default set up conference with FS). Want to create a 100+ participant conference where 3 calls per second will not suffice. ;-( thanks, Niall. System Info: Installed from default Windows MSI installer. 6GB Ram Windows 7 64 Bit Intel Core i7 920 CPU