Hello, I have a Sangoma A200 with 2 FXS and 2 FXO ports plugged into FreeSwitch and configured through wanpipe and FreeTDM. Incoming and outgoing calls work fine controlled through ESL. FS version is 1.4.8 wanpipe driver: 7.0.8 libsng_isdn: 7.29.0 for x86_64 machine OS: centos 6.4 I'm testing call hold/swap functionality. I'm using send_dtmf api to send 'F' followed by the number to simulate flash and dial a number on FXO line but the FS log shows following error: 2014-09-10 11:13:29.425811 [DEBUG] ftdm_io.c:3983 [s2c1][1:1] Generating DTMF [F1xxxxxx6146] 2014-09-10 11:13:29.425811 [ERR] ftmod_wanpipe.c:909 [s2c1][1:1] Wanpipe failed to execute command 18: Success 2014-09-10 11:13:29.425811 [ERR] ftdm_io.c:3576 I/O backend does not support command 18! command 18 corresponds to FTDM_COMMAND_FLASH but looks like it is not supported. On FS mailing list I saw one post where it was mentioned that this support is present but not clear whether it works end to end ( http://lists.freeswitch.org/pipermail/freeswitch-users/2010-September/062649...). What could be wrong? I've set analog-options in freetdm.conf.xml. Has anyone experienced this? Any suggestions? Thanks, Kalyani