Documentation/isdn/INTERFACE.fax

   1 $Id: INTERFACE.fax,v 1.2 2000/08/06 09:22:50 armin Exp $
   2
   3
   4 Description of the fax-subinterface between linklevel and hardwarelevel of
   5   isdn4linux.
   6
   7   The communication between linklevel (LL) and hardwarelevel (HL) for fax
   8   is based on the struct T30_s (defined in isdnif.h).
   9   This struct is allocated in the LL.
  10   In order to use fax, the LL provides the pointer to this struct with the
  11   command ISDN_CMD_SETL3 (parm.fax). This pointer expires in case of hangup
  12   and when a new channel to a new connection is assigned.
  13
  14
  15 Data handling:
  16   In send-mode the HL-driver has to handle the <DLE> codes and the bit-order
  17   conversion by itself.
  18   In receive-mode the LL-driver takes care of the bit-order conversion
  19   (specified by +FBOR)
  20
  21 Structure T30_s description:
  22
  23   This structure stores the values (set by AT-commands), the remote-
  24   capability-values and the command-codes between LL and HL.
  25
  26   If the HL-driver receives ISDN_CMD_FAXCMD, all needed information
  27   is in this struct set by the LL.
  28   To signal information to the LL, the HL-driver has to set the
  29   parameters and use ISDN_STAT_FAXIND.
  30   (Please refer to INTERFACE)
  31
  32 Structure T30_s:
  33
  34   All members are 8-bit unsigned (__u8)
  35
  36   -  resolution
  37   -  rate
  38   -  width
  39   -  length
  40   -  compression
  41   -  ecm
  42   -  binary
  43   -  scantime
  44   -  id[]
  45   Local faxmachine's parameters, set by +FDIS, +FDCS, +FLID, ...
  46
  47   -  r_resolution
  48   -  r_rate
  49   -  r_width
  50   -  r_length
  51   -  r_compression
  52   -  r_ecm
  53   -  r_binary
  54   -  r_scantime
  55   -  r_id[]
  56   Remote faxmachine's parameters. To be set by HL-driver.
  57
  58   -  phase
  59   Defines the actual state of fax connection. Set by HL or LL
  60   depending on progress and type of connection.
  61   If the phase changes because of an AT command, the LL driver
  62   changes this value. Otherwise the HL-driver takes care of it, but
  63   only necessary on call establishment (from IDLE to PHASE_A).
  64   (one of the constants ISDN_FAX_PHASE_[IDLE,A,B,C,D,E])
  65
  66   -  direction
  67   Defines outgoing/send or incoming/receive connection.
  68   (ISDN_TTY_FAX_CONN_[IN,OUT])
  69
  70   -  code
  71   Commands from LL to HL; possible constants :
  72       ISDN_TTY_FAX_DR        signals +FDR command to HL
  73
  74       ISDN_TTY_FAX_DT        signals +FDT command to HL
  75
  76       ISDN_TTY_FAX_ET        signals +FET command to HL
  77
  78
  79   Other than that the "code" is set with the hangup-code value at
  80   the end of connection for the +FHNG message.
  81
  82   -  r_code
  83   Commands from HL to LL; possible constants :
  84       ISDN_TTY_FAX_CFR       output of +FCFR message.
  85
  86       ISDN_TTY_FAX_RID       output of remote ID set in r_id[]
  87                              (+FCSI/+FTSI on send/receive)
  88
  89       ISDN_TTY_FAX_DCS       output of +FDCS and CONNECT message,
  90                              switching to phase C.
  91
  92       ISDN_TTY_FAX_ET        signals end of data,
  93                              switching to phase D.
  94
  95       ISDN_TTY_FAX_FCON      signals the established, outgoing connection,
  96                              switching to phase B.
  97
  98       ISDN_TTY_FAX_FCON_I    signals the established, incoming connection,
  99                              switching to phase B.
 100
 101       ISDN_TTY_FAX_DIS       output of +FDIS message and values.
 102
 103       ISDN_TTY_FAX_SENT      signals that all data has been sent
 104                              and <DLE><ETX> is acknowledged,
 105                              OK message will be sent.
 106
 107       ISDN_TTY_FAX_PTS       signals a msg-confirmation (page sent successful),
 108                              depending on fet value:
 109                              0: output OK message (more pages follow)
 110                              1: switching to phase B (next document)
 111
 112       ISDN_TTY_FAX_TRAIN_OK  output of +FDCS and OK message (for receive mode).
 113
 114       ISDN_TTY_FAX_EOP       signals end of data in receive mode,
 115                              switching to phase D.
 116
 117       ISDN_TTY_FAX_HNG       output of the +FHNG and value set by code and
 118                              OK message, switching to phase E.
 119
 120
 121   -  badlin
 122   Value of +FBADLIN
 123
 124   -  badmul
 125   Value of +FBADMUL
 126
 127   -  bor
 128   Value of +FBOR
 129
 130   -  fet
 131   Value of +FET command in send-mode.
 132   Set by HL in receive-mode for +FET message.
 133
 134   -  pollid[]
 135   ID-string, set by +FCIG
 136
 137   -  cq
 138   Value of +FCQ
 139
 140   -  cr
 141   Value of +FCR
 142
 143   -  ctcrty
 144   Value of +FCTCRTY
 145
 146   -  minsp
 147   Value of +FMINSP
 148
 149   -  phcto
 150   Value of +FPHCTO
 151
 152   -  rel
 153   Value of +FREL
 154
 155   -  nbc
 156   Value of +FNBC (0,1)
 157   (+FNBC is not a known class 2 fax command, I added this to change the
 158    automatic "best capabilities" connection in the eicon HL-driver)
 159
 160
 161 Armin
 162 mac@melware.de
 163