Let's say I'm routing orders to ARCA and I want to quickly (automatically) cancel/submit orders. I'm using Sterling and the clearing is done by PAX in Chicago. Does my order get matched in Chicago or is there a central ARCA server in NYC or NJ that orders are going to? If the latter, how fast is that connection between Chicago and NYC? This AT&T graphic says it's 22ms from CHI to NYC. http://ipnetwork.bgtmo.ip.att.net/pws/network_delay.html Speed of light is 186,000miles/s and CHI is 711.47 miles from NYC, which I guess means light can get there and back 130.7 times per second - so I guess that's the physical barrier: 7.65ms.