I've patched my rxfax to output to a separate files all the infoes.
And also to hook and print the 3 phase handler.
Here it is a failed fax.
Used: 0.0.4pre10
FLOW T.30 HDLC carrier up in state 1
FLOW T.30 HDLC carrier down in state 1
FLOW T.30 HDLC carrier up in state 1
FLOW T.30 HDLC carrier down in state 1
FLOW T.30 HDLC carrier up in state 1
FLOW T.30 Send complete in phase T30_PHASE_A_CED, state 1
FLOW T.30 Starting answer mode
FLOW T.30 Changing from phase T30_PHASE_A_CED to T30_PHASE_B_TX
FLOW FAX Set rx type 0
FLOW FAX Set tx type 4
FLOW T.30 DIS:
FLOW T.30 .... ...0= Store and forward Internet fax (T.37): Not set
FLOW T.30 .... .0..= Real-time Internet fax (T.38): Not set
FLOW T.30 .... 0...= 3G mobile network: Not set
FLOW T.30 ..0. ....= V.8 capabilities: Not set
FLOW T.30 .0.. ....= Preferred octets: 256 octets
FLOW T.30 .... ...0= Ready to transmit a fax document (polling): Not set
FLOW T.30 .... ..0.= Can receive fax: Not set
FLOW T.30 ..10 11..= Supported data signalling rates: V.27 ter, V.29, and V.17
FLOW T.30 .1.. ....= R8x7.7lines/mm and/or 200x200pels/25.4mm: Set
FLOW T.30 1... ....= 2-D coding: Set
FLOW T.30 .... ..00= Recording width: 215mm +- 1%
FLOW T.30 .... 10..= Recording length: Unlimited
FLOW T.30 .111 ....= Receiver's minimum scan line time: 0ms at 3.85 l/mm; T7.7 = T3.85
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ..0.= Compressed/uncompressed mode: Compressed
FLOW T.30 .... .0..= Error correction mode (ECM): Non-ECM
FLOW T.30 .0.. ....= T.6 coding: Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...0= "Field not valid" supported: Not set
FLOW T.30 .... ..0.= Multiple selective polling: Not set
FLOW T.30 .... .0..= Polled subaddress: Not set
FLOW T.30 .... 0...= T.43 coding: Not set
FLOW T.30 ...0 ....= Plane interleave: Not set
FLOW T.30 ..0. ....= Voice coding with 32kbit/s ADPCM (Rec. G.726): Not set
FLOW T.30 .0.. ....= Reserved for the use of extended voice coding set: Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...1= R8x15.4lines/mm: Set
FLOW T.30 .... ..0.= 300x300pels/25.4mm: Not set
FLOW T.30 .... .0..= R16x15.4lines/mm and/or 400x400pels/25.4mm: Not set
FLOW T.30 .... 0...= Inch-based resolution preferred: Not set
FLOW T.30 ...1 ....= Metric-based resolution preferred: Set
FLOW T.30 ..0. ....= Minimum scan line time for higher resolutions: T15.4 = T7.7
FLOW T.30 .0.. ....= Selective polling: Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...0= Subaddressing: Not set
FLOW T.30 .... ..0.= Password: Not set
FLOW T.30 .... .0..= Ready to transmit a data file (polling): Not set
FLOW T.30 ...0 ....= Binary file transfer (BFT): Not set
FLOW T.30 ..0. ....= Document transfer mode (DTM): Not set
FLOW T.30 .0.. ....= Electronic data interchange (EDI): Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...0= Basic transfer mode (BTM): Not set
FLOW T.30 .... .0..= Ready to transfer a character or mixed mode document (polling): Not set
FLOW T.30 .... 0...= Character mode: Not set
FLOW T.30 ..0. ....= Mixed mode (Annex E/T.4): Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...0= Processable mode 26 (Rec. T.505): Not set
FLOW T.30 .... ..0.= Digital network capability: Not set
FLOW T.30 .... .0..= Duplex capability: Half only
FLOW T.30 .... 0...= JPEG coding: Not set
FLOW T.30 ...0 ....= Full colour mode: Not set
FLOW T.30 .0.. ....= 12bits/pel component: Not set
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ...0= No subsampling (1:1:1): Not set
FLOW T.30 .... ..0.= Custom illuminant: Not set
FLOW T.30 .... .0..= Custom gamut range: Not set
FLOW T.30 .... 1...= North American Letter (215.9mm x 279.4mm): Set
FLOW T.30 ...1 ....= North American Legal (215.9mm x 355.6mm): Set
FLOW T.30 ..0. ....= Single-progression sequential coding (Rec. T.85) basic: Not set
FLOW T.30 .0.. ....= Single-progression sequential coding (Rec. T.85) optional L0: Not set
FLOW T.30 0... ....= Extension indicator: Not set
FLOW T.30 Changing from state 1 to 17
FLOW T.30 Sending ident 'AGXPBX'
FLOW T.30 Tx: CSI without final frame tag
FLOW T.30 Tx: ff 03 40 58 42 50 73 75 69 72 75 63 72 65 4d 20 20 20 20 20 20 20 20
FLOW T.30 Send complete in phase T30_PHASE_B_TX, state 17
FLOW T.30 Tx: DIS with final frame tag
FLOW T.30 Tx: ff 13 80 00 ee f8 80 80 91 80 80 80 18
FLOW T.30 Send complete in phase T30_PHASE_B_TX, state 17
FLOW T.30 Send complete in phase T30_PHASE_B_TX, state 17
FLOW T.30 Changing from phase T30_PHASE_B_TX to T30_PHASE_B_RX
FLOW FAX Set rx type 4
FLOW FAX Set tx type 0
FLOW T.30 HDLC carrier up in state 17
FLOW T.30 HDLC carrier down in state 17
FLOW T.30 HDLC carrier up in state 17
FLOW T.30 HDLC framing OK in state 17
FLOW T.30 Rx: TSI without final frame tag
FLOW T.30 Rx: ff 03 43 20 20 20 20 20 20 20 20 20 20 41 49 4c 41 54 49 20 44 43 42
FLOW T.30 Remote fax gave TSI as: "BCD ITALIA "
FLOW T.30 Rx: DCS with final frame tag
FLOW T.30 Rx: ff 13 83 00 e2 f8 00
FLOW T.30 In state 17
FLOW T.30 DCS:
FLOW T.30 .... ...0= Store and forward Internet fax (T.37): Not set
FLOW T.30 .... .0..= Real-time Internet fax (T.38): Not set
FLOW T.30 .... 0...= 3G mobile network: Not set
FLOW T.30 .... ..1.= Can receive fax: Set
FLOW T.30 ..10 00..= Selected data signalling rate: V.17 14400bps
FLOW T.30 .1.. ....= R8x7.7lines/mm and/or 200x200pels/25.4mm: Set
FLOW T.30 1... ....= 2-D coding: Set
FLOW T.30 .... ..00= Recording width: 215mm +- 1%
FLOW T.30 .... 10..= Recording length: Unlimited
FLOW T.30 .111 ....= Minimum scan line time: 0ms
FLOW T.30 1... ....= Extension indicator: Set
FLOW T.30 .... ..0.= Compressed/uncompressed mode: Compressed
FLOW T.30 .... .0..= Error correction mode (ECM): Non-ECM
FLOW T.30 .... 0...= Frame size: 256 octets
FLOW T.30 .0.. ....= T.6 coding: Not set
FLOW T.30 0... ....= Extension indicator: Not set
FLOW T.30 Selected compression 2
[phase_b_handler] mark
FLOW T.30 Get document at 14400bps, modem 12
FLOW T.30 Changing from state 17 to 7
FLOW T.30 Changing from phase T30_PHASE_B_RX to T30_PHASE_C_NON_ECM_RX
FLOW FAX Set rx type 12
FLOW FAX Set tx type 0
FLOW T.30 Non-ECM carrier up in state 7
FLOW T.30 Non-ECM carrier training failed in state 7
FLOW T.30 Non-ECM carrier down in state 7
FLOW T.30 HDLC carrier down in state 7
FLOW T.30 Non-ECM carrier up in state 7
FLOW T.30 HDLC carrier up in state 7
FLOW T.30 Non-ECM carrier training failed in state 7
FLOW T.30 Non-ECM carrier down in state 7
FLOW T.30 HDLC carrier down in state 7
FLOW T.30 Non-ECM carrier up in state 7
FLOW T.30 HDLC carrier up in state 7
FLOW T.30 Non-ECM carrier trained in state 7
FLOW FAX Switching from V.17 + V.21 to V.17 (-17.63dBm0)
FLOW T.30 Non-ECM carrier down in state 7
FLOW T.30 Trainability test failed - longest run of zeros was 11497
FLOW T.30 Changing from phase T30_PHASE_C_NON_ECM_RX to T30_PHASE_B_TX
FLOW FAX Set rx type 0
FLOW FAX Set tx type 4
FLOW T.30 Changing from state 7 to 9
FLOW T.30 Tx: FTT with final frame tag
FLOW T.30 Tx: ff 13 44
FLOW T.30 Send complete in phase T30_PHASE_B_TX, state 9
FLOW T.30 Send complete in phase T30_PHASE_B_TX, state 9
FLOW T.30 Changing from phase T30_PHASE_B_TX to T30_PHASE_B_RX
FLOW FAX Set rx type 4
FLOW FAX Set tx type 0
FLOW T.30 HDLC carrier up in state 9
FLOW T.30 HDLC carrier down in state 9
FLOW T.30 HDLC carrier up in state 9
FLOW T.30 HDLC framing OK in state 9
FLOW T.30 Rx: DCS with final frame tag
FLOW T.30 Rx: ff 13 83 00 ea f8 00
FLOW T.30 In state 9
FLOW T.30 Unexpected DCS received in state 9
FLOW T.30 Changing from state 9 to 3
FLOW T.30 Tx: DCN with final frame tag
FLOW T.30 Tx: ff 13 fa
FLOW T.30 HDLC carrier down in state 3
FLOW T.30 Changing from phase T30_PHASE_B_RX to T30_PHASE_D_TX
FLOW FAX Set rx type 0
FLOW FAX Set tx type 4
FLOW T.30 Send complete in phase T30_PHASE_D_TX, state 3
FLOW T.30 Send complete in phase T30_PHASE_D_TX, state 3
FLOW T.30 Disconnecting
FLOW T.30 Changing from phase T30_PHASE_D_TX to T30_PHASE_E
FLOW FAX Set rx type 0
FLOW FAX Set tx type 1
FLOW T.30 Changing from state 3 to 2
FLOW T.30 Send complete in phase T30_PHASE_E, state 2
[FAX ERROR] code: 13 Unexpected message received