<div dir="ltr"><div>Hello,<br><br></div><div>Let say Alice and Bob both have a sip phone connected to the same asterisk 11 box.<br></div><div>Alice has T.38 enabled softphone.<br><br></div><div>When Alice sends a fax to Bob extension, the following happens on my system:<br>
</div><div>- Bob phone starts to ring<br></div><div>- Bob answers<br></div><div>- asterisk sends the incoming call to appropriate fax extension<br></div><div>- Bob is hearing nothing at all: no tone, no sound at all.<br><br>
</div><div>I want to play an audio file back to Bob, something "Do not panic, you are receiving a fax', before hanging up.<br><br></div><div>How can I do this ?<br><br></div><div>Playing with pre-dial handlers, I could enter the dialplan context I dedicated to this feature but obviously, inside that context, applications like Wait or Playback fail with messages like:<br>
<br></div><div> -- Executing [s@check-fax-reception:2] Playback("SIP/7005-0000028f", "tt-weasels") in new stack<br>[Aug 13 16:19:03] WARNING[24235][C-0000046f]: file.c:830 ast_readaudio_callback: Failed to write frame<br>
<br></div><div>Or:<br><br> -- Executing [s@check-fax-reception:2] Wait("SIP/7005-00000291", "0.5") in new stack<br> == Spawn extension (check-fax-reception, s, 2) exited non-zero on 'SIP/7005-00000291'<br>
[Aug 13 16:36:32] NOTICE[24309][C-00000470]: app_stack.c:1031 gosub_run: SIP/7005-00000291 Abnormal 'Gosub(check-fax-reception,s,1(SIP/7012-00000290,7005))' exit. Popping routine return locations.<br><br><br><br>
</div><div>My understanding is :<br></div><div>when a fax is detected and sent a fax extension, callee channel is in a state "close to termination" which is not compatible with many dialplan applications.<br><br>
<br></div><div>How can I work around this ?<br></div><div>Suggestions ?<br><br></div><div>Regards<br></div></div>