Hi, There are many of race conditions in pjmedia_stream that happen when the sip event thread and the media event thread try to use the stream at the same time. One such case is during hangup. In this case, they both try to call pjmedia_rtcp_build_rtcp_sdes() at the same time: sip event thread: #0 pjmedia_rtcp_build_rtcp_sdes pjproject/pjmedia/build/../src/pjmedia/rtcp.c:1014:10 #1 send_rtcp pjproject/pjmedia/build/../src/pjmedia/stream.c:991:11 #2 pjmedia_stream_send_rtcp_bye pjproject/pjmedia/build/../src/pjmedia/stream.c:2943:9 #3 pjsua_aud_stop_stream pjproject/pjsip/build/../src/pjsua-lib/pjsua_aud.c:505:2 #4 stop_media_stream pjproject/pjsip/build/../src/pjsua-lib/pjsua_media.c:2462:2 #5 stop_media_session pjproject/pjsip/build/../src/pjsua-lib/pjsua_media.c:2514:2 #6 pjsua_media_channel_deinit pjproject/pjsip/build/../src/pjsua-lib/pjsua_media.c:2538:5 #7 pjsua_call_on_state_changed pjproject/pjsip/build/../src/pjsua-lib/pjsua_call.c:3761:2 #8 inv_set_state pjproject/pjsip/build/../src/pjsip-ua/sip_inv.c:317:2 #9 inv_handle_bye_response pjproject/pjsip/build/../src/pjsip-ua/sip_inv.c:3407:2 #10 inv_on_state_confirmed pjproject/pjsip/build/../src/pjsip-ua/sip_inv.c:4746:2 #11 mod_inv_on_tsx_state pjproject/pjsip/build/../src/pjsip-ua/sip_inv.c:717:5 #12 pjsip_dlg_on_tsx_state pjproject/pjsip/build/../src/pjsip/sip_dialog.c:2064:2 #13 mod_ua_on_tsx_state pjproject/pjsip/build/../src/pjsip/sip_ua_layer.c:178:5 #14 tsx_set_state pjproject/pjsip/build/../src/pjsip/sip_transaction.c:1233:2 #15 tsx_on_state_proceeding_uac pjproject/pjsip/build/../src/pjsip/sip_transaction.c:2957:6 #16 tsx_on_state_calling pjproject/pjsip/build/../src/pjsip/sip_transaction.c:2540:2 #17 pjsip_tsx_recv_msg pjproject/pjsip/build/../src/pjsip/sip_transaction.c:1787:5 #18 mod_tsx_layer_on_rx_response pjproject/pjsip/build/../src/pjsip/sip_transaction.c:875:5 #19 pjsip_endpt_process_rx_data pjproject/pjsip/build/../src/pjsip/sip_endpoint.c:895:13 #20 endpt_on_rx_msg pjproject/pjsip/build/../src/pjsip/sip_endpoint.c:1037:5 #21 pjsip_tpmgr_receive_packet pjproject/pjsip/build/../src/pjsip/sip_transport.c:1938:2 #22 udp_on_read_complete pjproject/pjsip/build/../src/pjsip/sip_transport_udp.c:168:3 #23 ioqueue_dispatch_read_event pjproject/pjlib/build/../src/pj/ioqueue_common_abs.c:605:6 #24 pj_ioqueue_poll pjproject/pjlib/build/../src/pj/ioqueue_select.c:981:7 #25 pjsip_endpt_handle_events2 pjproject/pjsip/build/../src/pjsip/sip_endpoint.c:742:6 #26 pjsua_handle_events pjproject/pjsip/build/../src/pjsua-lib/pjsua_core.c:1981:14 #27 worker_thread pjproject/pjsip/build/../src/pjsua-lib/pjsua_core.c:699:10 #28 thread_main pjproject/pjlib/build/../src/pj/os_core_unix.c:541:27 media event thread: #0 pjmedia_rtcp_build_rtcp_sdes pjproject/pjmedia/build/../src/pjmedia/rtcp.c:1014:10 #1 send_rtcp pjproject/pjmedia/build/../src/pjmedia/stream.c:991:11 #2 on_rx_rtp pjproject/pjmedia/build/../src/pjmedia/stream.c:1905:11 #3 srtp_rtp_cb pjproject/pjmedia/build/../src/pjmedia/transport_srtp.c:1005:2 #4 on_rx_rtp pjproject/pjmedia/build/../src/pjmedia/transport_udp.c:533:6 #5 ioqueue_dispatch_read_event pjproject/pjlib/build/../src/pj/ioqueue_common_abs.c:605:6 #6 pj_ioqueue_poll pjproject/pjlib/build/../src/pj/ioqueue_select.c:981:7 #7 worker_proc pjproject/pjmedia/build/../src/pjmedia/endpoint.c:339:2 #8 thread_main pjproject/pjlib/build/../src/pj/os_core_unix.c:541:27 Kal _______________________________________________ Visit our blog: http://blog.pjsip.org pjsip mailing list pjsip@xxxxxxxxxxxxxxx http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org