Hello, I have getting a strange issue, --null-audio working good if a audio device present in the machine. But if not, pjsip giving an error. Is there anything wrong I did? Anyone please share any idea. Running Version:2.9 Environment: Debian(Jessie) No Audio device installed. Just has snd_dummy. Running pjsip with following command: ./pjsua-x86_64-unknown-linux-gnu --ip-addr=192.168.1.136 --local-port=5060 --id=sip:123456@192.168.1.136 --play-file=../../../trunk/tests/pjsua/wavs/input.16.wav --auto-loop --null-audio Got this following error while received 200 Ok. 23:52:41.761 pjsua_app.c .....Call 0 state changed to CONNECTING 23:52:41.761 pjsua_media.c .....Call 0: updating media.. 23:52:41.761 pjsua_media.c .......Media stream call00:0 is destroyed 23:52:41.761 pjsua_aud.c ......Audio channel update.. 23:52:41.761 strm0x7f99ec0044b8 .......Encoder stream started 23:52:41.761 strm0x7f99ec0044b8 .......Decoder stream started 23:52:41.761 pjsua_media.c ......pjsua_aud_channel_update() failed for call_id 0 media 0: Invalid operation (PJ_EINVALIDOP) 23:52:41.761 pjsua_media.c .......Media stream call00:0 is destroyed 23:52:41.761 pjsua_media.c ......Error updating media call00:0: Invalid operation (PJ_EINVALIDOP) 23:52:41.761 pjsua_call.c .....Unable to create media session: No active media stream after negotiation (PJMEDIA_SDPNEG_ENOMEDIA) [status=220048] Thanks, Rubel