I'm wondering if hdlc can be the culprit (not sure what it is and what it does). Should I set hdlc to yes in misdn.conf (I'm asking before testing because this is a production system)? misdn.conf: [general] misdn_init=/etc/misdn-init.conf debug=0 ntdebugflags=0 ntdebugfile=/var/log/misdn-nt.log ntkeepcalls=no bridging=no stop_tone_after_first_digit=yes append_digits2exten=yes dynamic_crypt=no crypt_prefix=** crypt_keys=test,muh [default] context=misdn language=us musicclass=default senddtmf=yes far_alerting=no allowed_bearers=all nationalprefix=0 internationalprefix=00 rxgain=0 txgain=0 te_choose_channel=no pmp_l1_check=no reject_cause=16 need_more_infos=no nttimeout=no method=standard overlapdial=yes dialplan=0 localdialplan=0 cpndialplan=0 early_bconnect=yes incoming_early_audio=no nodialtone=no presentation=-1 screen=-1 echocancel=yes echotraining=no jitterbuffer=4000 jitterbuffer_upper_threshold=0 hdlc=no [MY_ISDN] context=from-isdn-custom ports=1,2,3,4 msns=* Asterisk 1.2.31.1 built by root @ voip1 on a i686 running Linux on 2009-03-10 17:38:30 UTC Linux voip1 2.6.23-gentoo-r8 #1 SMP Fri Oct 17 01:10:38 CEST 2008 i686 Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz GenuineIntel GNU/Linux misdn 1.1.7.2 misdnuser 1.1.7.2 asterisk-chan_misdn 0.3.1 iaxmodem 1.1.1 The receiving hylafax log (11111111111 is the fax number): Nov 05 11:10:29.18: [11410]: SESSION BEGIN 000000370 11111111111 Nov 05 11:10:29.18: [11410]: HylaFAX (tm) Version 4.4.4 Nov 05 11:10:32.90: [11410]: ANSWER: FAX CONNECTION DEVICE '/dev/ttyIAX10006' Nov 05 11:11:18.58: [11410]: SESSION END The sending hylafax log: Nov 05 11:10:09.31: [13507]: SESSION BEGIN 000008383 1111111111111111 Nov 05 11:10:09.31: [13507]: HylaFAX (tm) Version 4.2.5 Nov 05 11:10:09.31: [13507]: SEND FAX: JOB 5050 DEST 111111111 COMMID 000008383 DEVICE '/dev/ttyS1' FROM 'vieri <vieri at mydomain.com>' USER vieri Nov 05 11:10:09.31: [13507]: <-- [12:AT+FCLASS=1\r] Nov 05 11:10:09.42: [13507]: --> [2:OK] Nov 05 11:10:09.42: [13507]: DIAL 111111111 Nov 05 11:10:09.42: [13507]: <-- [14:ATDT111111111\r] Nov 05 11:10:18.76: [13507]: --> [7:CONNECT] Nov 05 11:10:19.90: [13507]: --> [2:OK] Nov 05 11:10:19.90: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:19.90: [13507]: DELAY 70 ms Nov 05 11:10:19.97: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:20.02: [13507]: --> [7:CONNECT] Nov 05 11:10:20.02: [13507]: <-- data [3] Nov 05 11:10:20.02: [13507]: <-- data [2] Nov 05 11:10:21.33: [13507]: --> [2:OK] Nov 05 11:10:21.33: [13507]: SEND send CRP (command repeat) Nov 05 11:10:21.34: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:21.65: [13507]: --> [7:CONNECT] Nov 05 11:10:26.26: [13507]: --> [2:OK] Nov 05 11:10:26.26: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:26.26: [13507]: DELAY 70 ms Nov 05 11:10:26.33: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:26.38: [13507]: --> [7:CONNECT] Nov 05 11:10:26.38: [13507]: <-- data [3] Nov 05 11:10:26.38: [13507]: <-- data [2] Nov 05 11:10:27.69: [13507]: --> [2:OK] Nov 05 11:10:27.70: [13507]: SEND send CRP (command repeat) Nov 05 11:10:27.70: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:27.94: [13507]: --> [7:CONNECT] Nov 05 11:10:30.61: [13507]: --> [2:OK] Nov 05 11:10:30.61: [13507]: REMOTE NSF "AD 00 55 48 79 6C 61 46 41 58 20 28 74 6D 29 20 56 65 72 73 69 6F 6E 20 34 2E 34 2E 34" Nov 05 11:10:30.61: [13507]: NSF remote fax equipment: unknown Nov 05 11:10:30.61: [13507]: NSF possible remote station ID: "HylaFAX (tm) Version 4.4.4" Nov 05 11:10:30.61: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:30.85: [13507]: --> [7:CONNECT] Nov 05 11:10:35.56: [13507]: --> [2:OK] Nov 05 11:10:35.56: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:35.56: [13507]: DELAY 70 ms Nov 05 11:10:35.64: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:35.68: [13507]: --> [7:CONNECT] Nov 05 11:10:35.68: [13507]: <-- data [3] Nov 05 11:10:35.68: [13507]: <-- data [2] Nov 05 11:10:37.00: [13507]: --> [2:OK] Nov 05 11:10:37.00: [13507]: SEND send CRP (command repeat) Nov 05 11:10:37.00: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:37.26: [13507]: --> [7:CONNECT] Nov 05 11:10:39.93: [13507]: --> [2:OK] Nov 05 11:10:39.93: [13507]: REMOTE NSF "AD 00 55 48 79 6C 61 46 41 58 20 28 74 6D 29 20 56 65 72 73 69 6F 6E 20 34 2E 34 2E 34" Nov 05 11:10:39.93: [13507]: NSF remote fax equipment: unknown Nov 05 11:10:39.93: [13507]: NSF possible remote station ID: "HylaFAX (tm) Version 4.4.4" Nov 05 11:10:39.93: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:40.17: [13507]: --> [7:CONNECT] Nov 05 11:10:44.87: [13507]: --> [2:OK] Nov 05 11:10:44.87: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:44.87: [13507]: DELAY 70 ms Nov 05 11:10:44.94: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:45.00: [13507]: --> [7:CONNECT] Nov 05 11:10:45.00: [13507]: <-- data [3] Nov 05 11:10:45.00: [13507]: <-- data [2] Nov 05 11:10:46.31: [13507]: --> [2:OK] Nov 05 11:10:46.31: [13507]: SEND send CRP (command repeat) Nov 05 11:10:46.31: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:46.58: [13507]: --> [7:CONNECT] Nov 05 11:10:47.87: [13507]: --> [2:OK] Nov 05 11:10:47.87: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:47.87: [13507]: DELAY 70 ms Nov 05 11:10:47.94: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:47.99: [13507]: --> [7:CONNECT] Nov 05 11:10:47.99: [13507]: <-- data [3] Nov 05 11:10:47.99: [13507]: <-- data [2] Nov 05 11:10:49.31: [13507]: --> [2:OK] Nov 05 11:10:49.31: [13507]: SEND send CRP (command repeat) Nov 05 11:10:49.31: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:49.49: [13507]: --> [7:CONNECT] Nov 05 11:10:54.28: [13507]: --> [2:OK] Nov 05 11:10:54.28: [13507]: HDLC frame too short (0 bytes) Nov 05 11:10:54.28: [13507]: DELAY 70 ms Nov 05 11:10:54.35: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:10:54.40: [13507]: --> [7:CONNECT] Nov 05 11:10:54.40: [13507]: <-- data [3] Nov 05 11:10:54.40: [13507]: <-- data [2] Nov 05 11:10:55.71: [13507]: --> [2:OK] Nov 05 11:10:55.71: [13507]: SEND send CRP (command repeat) Nov 05 11:10:55.71: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:55.98: [13507]: --> [7:CONNECT] Nov 05 11:10:58.66: [13507]: --> [2:OK] Nov 05 11:10:58.66: [13507]: REMOTE NSF "AD 00 55 48 79 6C 61 46 41 58 20 28 74 6D 29 20 56 65 72 73 69 6F 6E 20 34 2E 34 2E 34" Nov 05 11:10:58.66: [13507]: NSF remote fax equipment: unknown Nov 05 11:10:58.66: [13507]: NSF possible remote station ID: "HylaFAX (tm) Version 4.4.4" Nov 05 11:10:58.66: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:10:58.90: [13507]: --> [7:CONNECT] Nov 05 11:11:03.58: [13507]: --> [2:OK] Nov 05 11:11:03.58: [13507]: HDLC frame too short (0 bytes) Nov 05 11:11:03.58: [13507]: DELAY 70 ms Nov 05 11:11:03.65: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:11:03.70: [13507]: --> [7:CONNECT] Nov 05 11:11:03.70: [13507]: <-- data [3] Nov 05 11:11:03.70: [13507]: <-- data [2] Nov 05 11:11:05.02: [13507]: --> [2:OK] Nov 05 11:11:05.02: [13507]: SEND send CRP (command repeat) Nov 05 11:11:05.02: [13507]: <-- [9:AT+FRH=3\r] Nov 05 11:11:09.98: [13507]: --> [2:OK] Nov 05 11:11:09.98: [13507]: DELAY 200 ms Nov 05 11:11:10.18: [13507]: No answer (T.30 T1 timeout) Nov 05 11:11:10.18: [13507]: SEND FAILED: JOB 5050 DEST 111111111 ERR No answer (T.30 T1 timeout) Nov 05 11:11:10.18: [13507]: <-- [9:AT+FTH=3\r] Nov 05 11:11:10.23: [13507]: --> [7:CONNECT] Nov 05 11:11:10.23: [13507]: <-- data [3] Nov 05 11:11:10.23: [13507]: <-- data [2] Nov 05 11:11:11.55: [13507]: --> [2:OK] Nov 05 11:11:11.55: [13507]: <-- [5:ATH0\r] Nov 05 11:11:11.97: [13507]: --> [10:NO CARRIER] Nov 05 11:11:11.97: [13507]: MODEM No carrier Nov 05 11:11:11.97: [13507]: SESSION END If you need other logging information, please let me know. Thanks, Vieri