I have been playing around with mod_fax and can successfully receive a fax to file. However, while doing so mod_fax is logging an error message. Does anybody know what this error means? Dialplan: OpenZAP/2:1/1011 parsing [default->REH_test_fax_receive] continue=false Dialplan: OpenZAP/2:1/1011 Regex (PASS) [REH_test_fax_receive] destination_number(1011) =~ /^1011$/ break=on-false Dialplan: OpenZAP/2:1/1011 Action disable_ec() Dialplan: OpenZAP/2:1/1011 Action answer() Dialplan: OpenZAP/2:1/1011 Action playback(silence_stream://2000) Dialplan: OpenZAP/2:1/1011 Action rxfax(/tmp/rxfax.tif) Dialplan: OpenZAP/2:1/1011 Action hangup() 2010-02-16 16:27:08.542746 [DEBUG] switch_core_state_machine.c:122 (OpenZAP/2:1/1011) State Change CS_ROUTING -> CS_EXECUTE 2010-02-16 16:27:08.542746 [DEBUG] switch_core_session.c:1019 Send signal OpenZAP/2:1/1011 [BREAK] 2010-02-16 16:27:08.542746 [DEBUG] switch_core_state_machine.c:341 (OpenZAP/2:1/1011) State ROUTING going to sleep 2010-02-16 16:27:08.542746 [DEBUG] switch_core_state_machine.c:314 (OpenZAP/2:1/1011) Running State Change CS_EXECUTE 2010-02-16 16:27:08.542746 [DEBUG] switch_core_state_machine.c:348 (OpenZAP/2:1/1011) State EXECUTE 2010-02-16 16:27:08.542746 [DEBUG] mod_openzap.c:434 OpenZAP/2:1/1011 CHANNEL EXECUTE 2010-02-16 16:27:08.542746 [DEBUG] switch_core_state_machine.c:159 OpenZAP/2:1/1011 Standard EXECUTE 2010-02-16 16:27:08.542746 [DEBUG] switch_core_session.c:1521 Application disable_ec Requires media! pre_answering channel OpenZAP/2:1/1011 2010-02-16 16:27:08.542746 [DEBUG] switch_core_session.c:1523 OpenZAP/2:1/1011 receive message [PROGRESS] 2010-02-16 16:27:08.542746 [DEBUG] mod_openzap.c:960 Changing state on 2:1 from IDLE to UP 2010-02-16 16:27:08.542746 [NOTICE] mod_openzap.c:961 Channel [OpenZAP/2:1/1011] has been answered 2010-02-16 16:27:08.542746 [DEBUG] switch_channel.c:182 OpenZAP/2:1/1011 receive message [AUDIO_SYNC] 2010-02-16 16:27:08.542746 [DEBUG] switch_core_session.c:634 Send signal OpenZAP/2:1/1011 [BREAK] EXECUTE OpenZAP/2:1/1011 disable_ec() 2010-02-16 16:27:08.542746 [INFO] mod_openzap.c:2951 Echo Canceller Disabled EXECUTE OpenZAP/2:1/1011 answer() EXECUTE OpenZAP/2:1/1011 playback(silence_stream://2000) 2010-02-16 16:27:08.542746 [DEBUG] switch_ivr_play_say.c:1162 Codec Activated L16@8000hz 1 channels 20ms 2010-02-16 16:27:08.542746 [DEBUG] switch_core_io.c:652 OpenZAP/2:1/1011 receive message [TRANSCODING_NECESSARY] 2010-02-16 16:27:08.562747 [DEBUG] ozmod_analog.c:450 Executing state handler on 2:1 for UP 2010-02-16 16:27:08.562747 [DEBUG] mod_openzap.c:1463 got FXS sig [UP] 2010-02-16 16:27:10.522277 [DEBUG] switch_ivr_play_say.c:1454 done playing file EXECUTE OpenZAP/2:1/1011 rxfax(/tmp/rxfax.tif) 2010-02-16 16:27:10.522277 [DEBUG] mod_fax.c:591 Raw read codec activation Success L16 20000 2010-02-16 16:27:10.522277 [DEBUG] switch_core_codec.c:112 OpenZAP/2:1/1011 Push codec L16:10 2010-02-16 16:27:10.522277 [DEBUG] mod_fax.c:607 Raw write codec activation Success L16 2010-02-16 16:27:10.522277 [DEBUG] switch_channel.c:182 OpenZAP/2:1/1011 receive message [AUDIO_SYNC] 2010-02-16 16:27:10.542275 [DEBUG] switch_core_io.c:234 OpenZAP/2:1/1011 receive message [TRANSCODING_NECESSARY] 2010-02-16 16:28:14.982013 [DEBUG] ozmod_analog.c:788 EVENT [ONHOOK][2:1] STATE [UP] 2010-02-16 16:28:14.982013 [DEBUG] ozmod_analog.c:824 Changing state on 2:1 from UP to DOWN 2010-02-16 16:28:14.992014 [DEBUG] ozmod_analog.c:450 Executing state handler on 2:1 for DOWN 2010-02-16 16:28:14.992014 [DEBUG] mod_openzap.c:1463 got FXS sig [STOP] 2010-02-16 16:28:14.992014 [NOTICE] mod_openzap.c:1554 Hangup OpenZAP/2:1/1011 [CS_EXECUTE] [NORMAL_CLEARING] 2010-02-16 16:28:14.992014 [DEBUG] switch_channel.c:1976 Send signal OpenZAP/2:1/1011 [KILL] 2010-02-16 16:28:15.002011 [ERR] mod_fax.c:666 Cannot write frame [datalen: 320, samples: 160] 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:167 ============================================================================ == 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:174 Fax successfully received. 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:185 Remote station id: 206 742 3831 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:186 Local station id: SpanDSP Fax Ident 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:187 Pages transferred: 1 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:189 Total fax pages: 1 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:190 Image resolution: 8031x3850 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:191 Transfer Rate: 9600 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:193 ECM status off 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:194 remote country: 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:195 remote vendor: 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:196 remote model: 2010-02-16 16:28:15.002011 [DEBUG] mod_fax.c:198 ============================================================================ == I traced the error message as coming from switch_core_session_write_frame in src/switch_core_io.c which returns SWITCH_STATUS_FALSE. Thanks for any information, Robert