1) Attempting to call pjsip_tcp_transport_start() more than once produces error code PJSIP_ETYPEEXISTS. I guess attaching more than one TCP socket should be done differently -- if so, how? 2) Calling pjsip_xfer_init_module() causes a crash with the stack pj_stricmp(const pj_str_t * 0x00000008, const pj_str_t * 0x08619550 _STR_REFER) line 205 + 3 bytes find_pkg(const pj_str_t * 0x08619550 _STR_REFER) line 382 + 16 bytes pjsip_evsub_register_pkg(pjsip_module * 0x08623118 mod_xfer, const pj_str_t * 0x08619550 _STR_REFER, unsigned int 300, unsigned int 1, const pj_str_t * 0x00121dd4) line 410 + 9 bytes pjsip_xfer_init_module(pjsip_endpoint * 0x0222ea7c) line 156 + 26 bytes Without attempt to init the REFER package the system seems to initialize fine. Is it a bug, or am I doing something wrong? 3) Is there an API to control the buffer size for SIP sockets? Thanks, Alex