What is the standard way of dealing with 401/407 server headers? Is there any callback must be installed to handle answers for this server messages? I am asking because my app seems to freeze after it recieves SIP/2.0 407 Proxy Authentication Required. If i make 1 call simultaneously all works ok. If i set more than 1.. say 6 or 8- or 16.. it freezes. I have checked.. max calls set to 32.. max ports to 255... I going to try to recompile with #define PJSIP_AUTH_AUTO_SEND_NEXT 1 and see if it help. but still: what is the preferred way? some callback must be installed? (i am working frop python with py_pjsua .. pjsip 2 month old svn version)