I've been using spandsp and rxfax to receive faxes for a while now and over the past few days I've looked into the other side of things - txfax. I can't seem to get it working properly. I've included debug logs below of both the tx and rx side of things. I've tried three different servers, asterisk v1.0.6, 1.0.9 and CVS, FC2 and FC4, libtiff 3.5.7 and 3.7.1, TE405P and TE110P cards, connected to each other via crossover cable (with rxfax as a fax client), the TE405P connected to itself (ports one and two crossover cable), and also connected to the PSTN with a hardfax on the other end. I always get the same errors. Would be very grateful if someone could give me some pointers or otherwise shed some light. The logs below are from spandsp 0.0.2 pre18 on CVS Head txfax talking to 0.0.2 pre18 on v1.0.9 stable rxfax. Doesn't matter though as the last debug entry is always the same (T4 timeout in state 4) ***** TXFAX Debug ***** -- Executing TxFAX("Zap/1-1", "/tmp/11236686843.tif|caller|debug") in new stack Slow carrier up Urgent handler Slow carrier down Slow carrier up Slow carrier down Slow carrier up Slow carrier down Slow carrier up Slow carrier down Slow carrier up <<< DIS: 80 00 ce f4 80 80 81 80 80 80 18 DIS with final frame tag In state 10 DIS: Prefer 256 octet blocks Can receive fax Supported data signalling rates: V.27ter and V.29 R8x7.7lines/mm and/or 200x200pels/25.4mm 2D coding Scan line length: 215mm Recording length: Unlimited Receiver's minimum scan line time: 0ms at 3.85 l/mm: T7.7 = T3.85 R8x15.4lines/mm Minimum scan line time for higher resolutions: T15.4 = T7.7 North American Letter (215.9mm x 279.4mm) North American Legal (215.9mm x 355.6mm) DCS: Can receive fax Selected data signalling rate: V.29, 9600bps 2D coding Scan line length: 215mm Recording length: A4 (297mm) Minimum scan line time: 20ms Minimum scan line time for higher resolutions: T15.4 = T7.7 Start sending document Start tx document Changed from phase 2 to 4>>> DCS: 83 00 86 80 80 80 00HDLC underflow in state 3 Changed from phase 4 to 6 Changed from phase 6 to 3 Slow carrier up T4 timeout in state 4 ***** End of txfax debug ***** ***** RXFAX debug ***** Aug 12 11:00:12 DEBUG[11937]: pbx.c:1274 pbx_extension_helper: Launching 'RxFAX' -- Executing RxFAX("Zap/1-1", "/var/mbox/msgs/1123815612.2.tif|debug") in new stack Urgent handler Aug 12 11:00:12 DEBUG[11937]: channel.c:1752 ast_set_read_format: Set channel Zap/1-1 to read format slin Aug 12 11:00:12 DEBUG[11937]: channel.c:1719 ast_set_write_format: Set channel Zap/1-1 to write format slin Slow carrier up Slow carrier down Aug 12 11:00:12 DEBUG[11937]: chan_zap.c:4138 my_zt_write: Write returned -1 (Resource temporarily unavailable) on channel 1 Slow carrier up Slow carrier down Slow carrier up Slow carrier down Slow carrier up Changed from phase 1 to 4 DIS: Prefer 256 octet blocks Can receive fax Supported data signalling rates: V.27ter and V.29 R8x7.7lines/mm and/or 200x200pels/25.4mm 2D coding Scan line length: 215mm Recording length: Unlimited Receiver's minimum scan line time: 0ms at 3.85 l/mm: T7.7 = T3.85 R8x15.4lines/mm Minimum scan line time for higher resolutions: T15.4 = T7.7 North American Letter (215.9mm x 279.4mm) North American Legal (215.9mm x 355.6mm)>>> DIS: 80 00 ce f4 80 80 81 80 80 80 18Aug 12 11:00:16 DEBUG[11937]: chan_zap.c:4053 zt_read: DTMF digit: f on Zap/1-1 Aug 12 11:00:16 DEBUG[11937]: chan_zap.c:4095 zt_read: Fax already handled HDLC underflow in state 9 Changed from phase 4 to 3 Slow carrier up Slow carrier down Slow carrier up Slow carrier down Slow carrier up <<< DCS: 83 00 86 80 80 80 00 DCS with final frame tag In state 9 DCS: Can receive fax Selected data signalling rate: V.29, 9600bps 2D coding Scan line length: 215mm Recording length: A4 (297mm) Minimum scan line time: 20ms Minimum scan line time for higher resolutions: T15.4 = T7.7 Get at 9600bps, modem 1 Changed from phase 3 to 5 Fast carrier up Fast carrier down Fast carrier up Coarse carrier frequency 1699.90 (68) Training error 0.294910 Training succeeded (constellation mismatch 0.636352) Fast carrier trained Craig