You have 0 active call
>>> m
(You currently have 0 calls)
Buddy list:
 -none-

Choices:
   0         For current dialog.
  -1         All 0 buddies in buddy list
  [1 - 0]    Select from buddy list
  URL        An URL
  <Enter>    Empty input (or 'q') to cancel
Make call: m sip:600@asterisk01
11:13:00.022     pjsua_app_legacy.c !Invalid URL: Invalid URI (PJSIP_EINVALIDURI) [status=171039]
11:13:00.022           pjsua_call.c  Making call with acc #2 to
11:13:00.022            pjsua_aud.c  .Set sound device: capture=-1, playback=-2
11:13:00.022            pjsua_aud.c  ..Error retrieving default audio device parameters: Unable to find default audio device (PJMEDIA_EAUD_NODEFDEV) [status=420006]