Hello, I am building a Python application based on pjsua library. One functionality involves detecting dtmf digits. The caller goes through a SIP trunk, and sends DTMF signals to the Python SIP user agent I am creating. My understanding is that the SIP trunk uses RFC 2833 to send RTP packets for DTMF digits. However, the on_dtmf_digit method I added to my CallCallback class is never run. def on_dtmf_digit(self, digits): print "DTMF received, digit=", digits outputs nothing. I made testings using pjsua command line tool to trace packets, however nothing is traced when I send DTMF digits. Should'nt I notice incoming RTP packets when hitting the telephone numbers? Thank you for your help. Eric

Hi, I have done several tests with pjsua command line. When I make a direct call over the LAN to pjsua from a SIP phone (MicroSIP installed on a Windows PC), pjsua correctly detects DTMF digits. Exemple output: 09:52:30.173 pjsua_app.c ...Call 1 state changed to CONFIRMED 09:52:30.788 strm0xac896c VAD re-enabled 09:53:09.372 pjsua_app.c .Incoming DTMF on call 1: 1 09:53:10.805 pjsua_app.c .Incoming DTMF on call 1: 2 09:53:11.586 pjsua_app.c .Incoming DTMF on call 1: 3 09:53:12.471 pjsua_app.c .Incoming DTMF on call 1: 4 09:53:13.232 pjsua_app.c .Incoming DTMF on call 1: 5 09:53:13.832 pjsua_app.c .Incoming DTMF on call 1: 6 09:53:14.472 pjsua_app.c .Incoming DTMF on call 1: 7 09:53:14.868 pjsua_app.c .Incoming DTMF on call 1: 8 09:53:15.387 pjsua_app.c .Incoming DTMF on call 1: 9 09:53:17.113 pjsua_app.c .Incoming DTMF on call 1: * 09:53:17.692 pjsua_app.c .Incoming DTMF on call 1: 0 09:53:18.332 pjsua_app.c .Incoming DTMF on call 1: # Now, if pjsua registers to a SIP trunk to call a phone number, the call succeeds, however pjsua does not detect DTMF digits sent from the phone. The trunk used is freephonie.net. Note that if I call some vocal server from the same phone, number keys seem to work well. My understanding is that the problem is somewhere between the SIP trunk and pjsua. I read in some old list message that a change between pjsip versions 1.5.5 and 1.8 in config.h had caused trouble with RFC2833 (changed PJMEDIA_RTP_PT_TELEPHONE_EVENTS from 101 to 96). Could it be related with my issue? Ref: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/2011-January/012500.html Any help will be greatly appreciated! Eric 2017-01-13 9:25 GMT+01:00 Eric Le Bras <eric.lebras@gmail.com>: > Hello, > > I am building a Python application based on pjsua library. One > functionality involves detecting dtmf digits. The caller goes through > a SIP trunk, and sends DTMF signals to the Python SIP user agent I am > creating. My understanding is that the SIP trunk uses RFC 2833 to send > RTP packets for DTMF digits. However, the on_dtmf_digit method I added > to my CallCallback class is never run. > > def on_dtmf_digit(self, digits): > print "DTMF received, digit=", digits > > outputs nothing. > > I made testings using pjsua command line tool to trace packets, > however nothing is traced when I send DTMF digits. Should'nt I notice > incoming RTP packets when hitting the telephone numbers? > > Thank you for your help. > > Eric