Hello I am facing a weird situation. I am trying to make a call to some destination using?pjsua_call_make_call(..). All works fine except when i try to make the call with headers added as a parameter to the API. Looking at the server log i can see that PJSIp is sending the ACX but not sending the INVITE again with the received proxy invitation string. This is the code i am using: pj_str_t hname = pj_str("Header1"); pj_str_t hvalue = pj_str("Value1"); pjsip_generic_string_hdr my_hdr; pjsip_generic_string_hdr_init2(&my_hdr, &hname, &hvalue); pjsua_msg_data msg_data; pjsua_msg_data_init(&msg_data); pj_list_push_back(&msg_data.hdr_list, &my_hdr); hname = pj_str("Header2"); hvalue = pj_str("Value2"); pjsip_generic_string_hdr my_hdr2; pjsip_generic_string_hdr_init2(&my_hdr2, &hname, &hvalue); pj_list_push_back(&msg_data.hdr_list, &my_hdr2); hname = pj_str("Header3"); hvalue = pj_str("Value3"); pjsip_generic_string_hdr my_hdr3; pjsip_generic_string_hdr_init2(&my_hdr3, &hname, &hvalue); pj_list_push_back(&msg_data.hdr_list, &my_hdr3); hname = pj_str("Header4"); hvalue = pj_str("Value4"); pjsip_generic_string_hdr my_hdr4; pjsip_generic_string_hdr_init2(&my_hdr4, &hname, &hvalue); pj_list_push_back(&msg_data.hdr_list, &my_hdr4); status = pjsua_call_make_call( current_acc, &tmp, 0, NULL, &msg_data, NULL); Please note that i am on PJSip 1.10 Cheers Fadi