I'm trying to enable MOH when both legs of the call are using G729 (FS is in passthru). I converted an edited sample wave file to G729 and put in the appropriate folder, and FS loads it correctly because this is the message that keeps popping up in the console: 2011-02-09 21:10:25.609375 [INFO] mod_native_file.c:94 Opening File [C:\freeswitch\sounds/music/8000\sample.G729] 8000hz I establish a call, and everything is fine, but when I press hold on my handset I see an error message that says that G729 is only useable in passthru (here is the debug message): 2011-02-09 21:14:01.828125 [DEBUG] switch_channel.c:1376 (sofia/internal/ sip:M9jdt73ig0oOJSbt6Uyy@192.168.1.50:5060) Callstate Change ACTIVE -> HELD 2011-02-09 21:14:01.828125 [DEBUG] switch_core_session.c:954 Send signal sofia/external/MYHOME#@74.63.41.218 [BREAK] 2011-02-09 21:14:01.859375 [DEBUG] switch_core_session.c:709 Send signal sofia/external/MYHOME#@74.63.41.218 [BREAK] 2011-02-09 21:14:02.000000 [DEBUG] switch_ivr.c:563 sofia/external/MYHOME#@ 74.63.41.218 Command Execute playback(local_stream://moh/8000) EXECUTE sofia/external/MYHOME#@74.63.41.218playback(local_stream://moh/8000) 2011-02-09 21:14:02.000000 [DEBUG] mod_local_stream.c:421 Opening Stream [moh/8000] 8000hz 2011-02-09 21:14:02.000000 [DEBUG] switch_ivr_play_say.c:1244 Codec Activated L16@8000hz 1 channels 20ms 2011-02-09 21:14:02.015625 [ERR] mod_g729.c:102 This codec is only usable in passthrough mode! 2011-02-09 21:14:02.015625 [ERR] switch_core_io.c:1042 Codec G.729 encoder error! 2011-02-09 21:14:02.015625 [DEBUG] switch_ivr_play_say.c:1581 done playing file I don't understand why that would be, since my music file is in G729 so I'm not asking freeswitch to convert, only stream. My custom ringback (before a call is established) works just fine using a similar method, so could anyone explain me why what I want to do is not permitted?