The includes are not the problem. Probably you do not "link" all required libraries. Check the linker options and make sure to add all pjsip libraries. My .pro file looks like this: LIBS += -L../pjproject-1.5.5/pjlib/lib \ -L../pjproject-1.5.5/pjlib-util/lib \ -L../pjproject-1.5.5/pjnath/lib \ -L../pjproject-1.5.5/pjmedia/lib \ -L../pjproject-1.5.5/pjsip/lib \ -L../pjproject-1.5.5/third_party/lib win32-g++:LIBS += -lpjsua-i686-pc-mingw32 \ -lpjsip-ua-i686-pc-mingw32 \ -lpjsip-simple-i686-pc-mingw32 \ -lpjsip-i686-pc-mingw32 \ -lpjmedia-codec-i686-pc-mingw32 \ -lpjmedia-i686-pc-mingw32 \ -lpjmedia-codec-i686-pc-mingw32 \ -lpjmedia-audiodev-i686-pc-mingw32 \ -lpjnath-i686-pc-mingw32 \ -lpjlib-util-i686-pc-mingw32 \ -lpj-i686-pc-mingw32 \ -lportaudio-i686-pc-mingw32 \ -lgsmcodec-i686-pc-mingw32 \ -lilbccodec-i686-pc-mingw32 \ -lspeex-i686-pc-mingw32 \ -lresample-i686-pc-mingw32 \ -lmilenage-i686-pc-mingw32 \ -lsrtp-i686-pc-mingw32 \ -lm \ -lwinmm \ -lole32 \ -lws2_32 \ -lwsock32 \ -lssl \ -lcrypto \ -lgdi32 regards Klaus Am 19.05.2010 17:55, schrieb mark hoppus: > Hi, > > I try to call pjsua_create function, but I get this error: > > unresolved external symbol _pjsua_create referenced in function "public: " > > here is my include header code: > > #ifdef __cplusplus > extern "C"{ > #endif > #include <pjlib.h> > #include <pjlib-util.h> > #include <pjnath.h> > #include <pjsip.h> > #include <pjsip_ua.h> > #include <pjsip_simple.h> > #include <pjsua-lib/pjsua.h> > #include <pjmedia.h> > #include <pjmedia-codec.h> > #ifdef __cplusplus > } > #endif > > I'm using Qt Creator and msvc. > > Need help. Thanks. > > > Rgds, > > > > _______________________________________________ > Visit our blog: http://blog.pjsip.org > > pjsip mailing list > pjsip at lists.pjsip.org > http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org