I don't think SIP MESSAGEs have a response/ack. I know that our provider doesn't send anything except the 200 OK when we send a message, and that doesn't mean it actually made it to the device. As far as I know there is no way to know if and when the device gets the actual message without the device responding with another message back through the via chain. -Chad From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Lucas Fontes Sent: Thursday, November 01, 2012 1:38 PM To: freeswitch-users@lists.freeswitch.org Subject: [Freeswitch-users] mod_sms delivery failure Hi everyone, I've been trying to determine if a message was successfully delivered to a device. Stumbled on a post from February (subject: Testing mod_sms) http://lists.freeswitch.org/pipermail/freeswitch-dev/2012-February/00561 9.html: ________________________________ From: Anthony Minessale <anthony.minessale at gmail.com <http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev> > To: Warren Lin <wlin121443 at yahoo.com <http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev> > Sent: Tuesday, February 21, 2012 11:01 AM Subject: Re: Testing mod_sms hi you can find out how to use the lists at http://lists.freeswitch.org try latest GIT, i put in a patch to fire the events with the heder Failed-Delivery true if you are listening for MESSAGE events you should catch them. ________________________________ I can't find any reference to Failed-Delivery in mod_sms.c neither anywhere else in the source tree. There is a field called Delivery-Failure, but seems to be used by other modules to indicate a failure on the response going out of freeswitch, not to freeswitch. Was this overwritten / rolled back at some point ? thanks -- lucas