(http://www.faximum.com/technotes/038)
TITLE: #038 - Problems Receiving or Transmitting (Analysing Trace Output) KEYWORDS: receive transmit errors FHNG FHS RELEASE: All CLASSIFICATION: All/All Topic-RX Topic-TX PROBLEM: Faxes are not being received or transmitted. Either the trace indicates an FHNG/FHS error or the log shows errors of the form "tx phase X:...". CAUSE: Many and varied SOLUTION: The following table lists the meaning of the FHNG/FHS codes seen in the trace output of faxlisten or faxcico. This list is a composite of those for a range of Class 2 modems. Most Class 2 modems will use similar status code but the documentation for the modem ought to be consulted to confirm the details. With Class 2.0 modems (such as U.S. Robotics), the message that reports the call termination status is called +FHS (+FHNG is the message from Class 2 modems). If you are examining the trace of commands and responses sent and received between the Faximum software and the modem, you will see +FHNG: or +FHS: responses from the modem. The table below describes the meaning of the various hangup status codes. If you are examing the system log, you will see messages of the form: "faxcico[nnn]: tx phase X: text of message (ss)" where nnn is the PID of the faxcico process X is the T.30 phase during which the error occurred: A - initial call setup B - pre-message negotiations C - send/receiving actual fax message D - post-message negotiations E - call release "text of message" is a simple message explaining the error (similar to the second column of the table below) ss is the status code (see the table below) The hangup values are organized according to the phases of the facsimile transaction as defined by T.30. A COMREC error or RSPREC error indicates that one of two events occurred. 1) a DCN (disconnect) signal was received from the far-end fax machine, or 2) an FCS (frame check sum) error was detected on data from the far-end fax machine and the incoming signal was still present after 3 seconds. The table values are in decimal notation for FHNG messages and in hexadecimal for the FHS message. Leading zero characters are optional. +==========+=================================================+ | Code | Cause Description | +==========+=================================================+ | 0... | CALL PLACEMENT AND TERMINATION | +----------+-------------------------------------------------+ | 00 | Normal and proper end of connection | | 01 | Ring Detect without successful handshake | | 02 | Call aborted, from +FK or AN | | 03 | No Loop Current (i.e. dead phone line) | | 04 | Ringback detected, no answer | | 05 | Ringback detected, answer, not a fax machine | +==========+=================================================+ | 10... | TRANSMIT PHASE A & MISCELLANEOUS ERRORS | +----------+-------------------------------------------------+ | 10 | Unspecified Phase A error | | 11 | No Answer (T.30 T1 timeout) | +==========+=================================================+ | 20... | TRANSMIT PHASE B HANGUP CODES | +----------+-------------------------------------------------+ | 20* | Unspecified Transmit Phase B error | | 21 | Remote cannot receive or send | | 22* | COMREC error in transmit Phase B | | 23* | COMREC invalid command received | | 24* | RSPEC error | | 25* | DCS sent three times without response | | 26* | DIS/DTC received 3 times; DCS not recognized | | 27 | Failure to train at 2400 bps or +FMINSP value | | 28* | RSPREC invalid response received | +==========+=================================================+ | 40... | TRANSMIT PHASE C HANGUP CODES | +----------+-------------------------------------------------+ | 40* | Unspecified Transmit Phase C error | | 41 | Unspecified Image Format error | | 42 | Image conversion error | | 43 | DTE to DCE data underflow | | 44 | Unrecognised Transparent data command | | 45 | Image error, line length wrong | | 46 | Image error, page length wrong | | 47 | Image error, wrong compression code | +==========+=================================================+ | 50... | TRANSMIT PHASE D HANGUP CODES | +----------+-------------------------------------------------+ | 50* | Unspecified Transmit Phase D error | | 51* | RSPREC error | | 52* | No response to MPS repeated 3 times | | 53* | Invalid response to MPS | | 54* | No response to EOP repeated 3 times | | 55* | Invalid response to EOM | | 56* | No response to EOM repeated 3 times | | 57* | Invalid response to EOM | | 58 | Unable to continue after PIN or PIP | +==========+=================================================+ | 70... | RECEIVE PHASE B HANGUP CODES | +----------+-------------------------------------------------+ | 70* | Unspecified Receive Phase B error | | 71* | RSPREC error | | 72* | COMREC error | | 73* | T.30 T2 timeout, expected page not received | | 74* | T.30 T1 timeout after EOM received | +==========+=================================================+ | 90... | RECEIVE PHASE C HANGUP CODES | +----------+-------------------------------------------------+ | 90 | Unspecified Receive Phase C error | | 91 | Missing EOL after 5 seconds | | 92 | Bad CRC or frame (ECM mode) | | 93 | DCE to DTE buffer overflow | | 94 | Bad CRC or frame (ECM or BFT modes) | +==========+=================================================+ | 100... | RECEIVE PHASE D HANGUP CODES (Class 2) | +----------+-------------------------------------------------+ | 100 | Unspecified Receive Phase D errors | | 101* | RSPREC invalid response received | | 102* | COMREC invalid response received | | 103 | Unable to continue after PIN or PIP | +==========+=================================================+ | A0... | RECEIVE PHASE D HANGUP CODES (Class 2.0) | +----------+-------------------------------------------------+ | A0 | Unspecified Receive Phase D errors | | A1* | RSPREC invalid response received | | A2* | COMREC invalid response received | | A3 | Unable to continue after PIN or PIP | +----------+-------------------------------------------------+ There are several possible causes for errors marked * in the table: 1) excessively noisy phone line which disrupts communications; 2) (in the case of transmission) far-end fax machine has run out of paper; 3) protocol incompatibility between the fax modem and the fax machine (see TN #117). If the same or similar error occurs repeatedly with faxes sent or received from the same fax machine then it is most likely a protocol incompatibility between the modem and the fax machine. These must be reportd to the modem manufacturer. Faximum will work with customers who are eligible for technical support to report these problems to the modem manufacturer and will work with the modem manufacturer's engineers to resolve the problem. Other errors with special meaning: 11 - If reported when a fax is being received, this means the modem answered an incoming call but did not hear the distinctive sounds of a fax machine calling. Usually caused when a human dials-up the fax modem by mistake. If reported when sending a fax, this means that the fax modem placed the call but did not hear the distinctive sounds of a fax machine answering the call. Usually caused by dialling a wrong number or a fax machine that is turned off or that has run out of paper. 41 and 44 - These suggest that the data being passed to the modem is not in the proper format. This could be caused either by a defect in the fax software or a problem with the serial communications port used to connect the modem. 43 - This means the computer could not send the data to the modem quickly enough to maintain the connection. Usually caused by setting the modem speed (in the appropriate Faximum configuration file) to less than 19,200. Can sometimes be caused by a machine which is overloaded. 93 - This means the computer would not accept data from the modem quickly enough to maintain the connection. Usually caused by setting the modem speed (in the appropriate Faximum configuration file) to less than 19,200. Can sometimes be caused by a machine which is overloaded. 58 and 103 (a.k.a. A3 on Class 2.0 modems) - These indicate that the far end device requested a transition from fax mode to voice mode. Since this cannot be done with a fax mode the call must be abandoned. It may also indicate a protocol incompatibility. For more information on MultiTech's implementation of the Fax Class 2 "Standard" please see: http://www.multitech.com/DOCUMENTS/manuals/82006502.pdf If you have any questions about analysing the output of a Faximum trace, fax or e-mail the entire trace to Faximum Technical Support. Tech Note: 038 - Copyright 1995-2001 Faximum Software Inc., All Rights Reserved. Last updated: Fri Feb 2 00:44:45 PST 2001 The complete set of Faximum TechNotes are available on the Internet at http://www.faximum.com/support/technotes© Copyright 2001 Faximum Software Inc. All Rights Reserved.