GPRS speeds with EDGE iPhone

[smasher]

I bought iPhone from us. It has edge. I enabled the 7 day GPRS service for re 75. I called up 121. The guy there told me that my place (chennai) where I live has edge facility. But I did a speed test to check the speed and got 45~60 Kbps but edge gives max 200kbps. Is the apn for edge and GPRS same I.e airtelgprs.com or is it different for edge?or Is EDGE and GPRS rates are different?does anyone know other edge areas in chennai?is edge available for the 7 day umlimted GPRS 75rs plan?thanks in advance