Thanks for your advices GIovanni but i already tried. I checked on the device manager , uninstalled the device , installed again the device , reloaded mod_gsmopen , used also the command gsm reload and same result unfortunatly , i tried all the port listed on device manager and inverted them to be sure nothing was wrong there. i also tried an other E153 device and on the Dashboard Mobil partner the port listed is the same than on the device manager and of course the dashboard isnt open when i use freeswitch to make sure the port com is available. i also checked on the source code the setup of the port com baud rate 115 200 "8N1" and i've made myself the same setup to make sure it will be compatible. I guess you worked on the Development of Gsm_open Giovanni, do you have any other idea ? Thanks -- View this message in context: http://freeswitch-users.2379917.n2.nabble.com/troubles-with-Mod-gsmopen-and-... Sent from the freeswitch-users mailing list archive at Nabble.com.