Just tried the most simple client http://www.pjsip.org/pjsip/docs/html/page_pjsip_sample_simple_pjsuaua_c.htm All registers fine but when I try to make a call I get 15:24:10.309 pjsua_media.c Error retrieving default audio device parameters: Unable to find default audio device (PJMEDIA_EAUD_NODEFDEV) [status=420006] I've checked the library. iphonesound.o is indeed included in libpjmedia-audiodev.a Any pointers what else to check? cheers -- Torsten