Initial import

1 files changed, 599 insertions, 0 deletions

diff --git a/Documentation/isdn/README b/Documentation/isdn/README
new file mode 100644
index 000000000..cfb188434
--- /dev/null
+++ b/Documentation/isdn/README
@@ -0,0 +1,599 @@
+README for the ISDN-subsystem
+
+1. Preface
+
+  1.1 Introduction
+
+  This README describes how to set up and how to use the different parts
+  of the ISDN-subsystem.
+
+  For using the ISDN-subsystem, some additional userlevel programs are
+  necessary. Those programs and some contributed utilities are available
+  at
+
+   ftp.isdn4linux.de
+
+   /pub/isdn4linux/isdn4k-utils-<VersionNumber>.tar.gz
+
+
+  We also have set up a mailing-list:
+
+   The isdn4linux-project originates in Germany, and therefore by historical
+   reasons, the mailing-list's primary language is german. However mails
+   written in english have been welcome all the time.
+
+   to subscribe: write a email to majordomo@listserv.isdn4linux.de,
+   Subject irrelevant, in the message body:
+   subscribe isdn4linux <your_email_address>
+
+   To write to the mailing-list, write to isdn4linux@listserv.isdn4linux.de
+
+   This mailinglist is bidirectionally gated to the newsgroup
+
+     de.alt.comm.isdn4linux
+
+  There is also a well maintained FAQ in English available at
+     http://www.mhessler.de/i4lfaq/
+  It can be viewed online, or downloaded in sgml/text/html format.
+  The FAQ can also be viewed online at
+     http://www.isdn4linux.de/faq/
+  or downloaded from
+     ftp://ftp.isdn4linux.de/pub/isdn4linux/FAQ/
+
+  1.1 Technical details
+
+  In the following Text, the terms MSN and EAZ are used.
+
+  MSN is the abbreviation for (M)ultiple(S)ubscriber(N)umber, and applies
+  to Euro(EDSS1)-type lines. Usually it is simply the phone number.
+
+  EAZ is the abbreviation of (E)ndgeraete(A)uswahl(Z)iffer and
+  applies to German 1TR6-type lines. This is a one-digit string,
+  simply appended to the base phone number
+
+  The internal handling is nearly identical, so replace the appropriate
+  term to that one, which applies to your local ISDN-environment.
+
+  When the link-level-module isdn.o is loaded, it supports up to 16
+  low-level-modules with up to 64 channels. (The number 64 is arbitrarily
+  chosen and can be configured at compile-time --ISDN_MAX in isdn.h).
+  A low-level-driver can register itself through an interface (which is
+  defined in isdnif.h) and gets assigned a slot.
+  The following char-devices are made available for each channel:
+
+  A raw-control-device with the following functions:
+     write: raw D-channel-messages (format: depends on driver).
+     read:  raw D-channel-messages (format: depends on driver).
+     ioctl: depends on driver, i.e. for the ICN-driver, the base-address of
+            the ports and the shared memory on the card can be set and read
+            also the boot-code and the protocol software can be loaded into
+            the card.
+
+   O N L Y !!!  for debugging (no locking against other devices):
+   One raw-data-device with the following functions:
+     write: data to B-channel.
+     read:  data from B-channel.
+
+   In addition the following devices are made available:
+
+   128 tty-devices (64 cuix and 64 ttyIx) with integrated modem-emulator:
+   The functionality is almost the same as that of a serial device
+   (the line-discs are handled by the kernel), which lets you run
+   SLIP, CSLIP and asynchronous PPP through the devices. We have tested
+   Seyon, minicom, CSLIP (uri-dip) PPP, mgetty, XCept and Hylafax. 
+
+   The modem-emulation supports the following:
+           1.3.1 Commands:
+
+               ATA      Answer incoming call.
+               ATD<No.> Dial, the number may contain:
+                        [0-9] and [,#.*WPT-S]
+                        the latter are ignored until 'S'.
+                        The 'S' must precede the number, if
+                        the line is a SPV (German 1TR6).
+               ATE0     Echo off.
+               ATE1     Echo on (default).
+               ATH      Hang-up.
+               ATH1     Off hook (ignored).
+               ATH0     Hang-up.
+               ATI      Return "ISDN for Linux...".
+               ATI0        "
+               ATI1        "
+               ATI2     Report of last connection.
+               ATO      On line (data mode).
+               ATQ0     Enable result codes (default).
+               ATQ1     Disable result codes (default).
+               ATSx=y   Set register x to y.
+               ATSx?    Show contents of register x.
+               ATV0     Numeric responses.
+               ATV1     English responses (default).
+               ATZ      Load registers and EAZ/MSN from Profile.
+               AT&Bx    Set Send-Packet-size to x (max. 4000)
+                        The real packet-size may be limited by the
+                        low-level-driver used. e.g. the HiSax-Module-
+                        limit is 2000. You will get NO Error-Message,
+                        if you set it to higher values, because at the
+                        time of giving this command the corresponding
+                        driver may not be selected (see "Automatic
+                        Assignment") however the size of outgoing packets
+                        will be limited correctly.
+               AT&D0    Ignore DTR
+               AT&D2    DTR-low-edge: Hang up and return to
+                        command mode (default).
+               AT&D3    Same as AT&D2 but also resets all registers.
+               AT&Ex    Set the EAZ/MSN for this channel to x.
+               AT&F     Reset all registers and profile to "factory-defaults"
+               AT&Lx    Set list of phone numbers to listen on.  x is a
+                        list of wildcard patterns separated by semicolon.
+                        If this is set, it has precedence over the MSN set
+                        by AT&E.
+               AT&Rx    Select V.110 bitrate adaption.
+                        This command enables V.110 protocol with 9600 baud
+                        (x=9600), 19200 baud (x=19200) or 38400 baud
+                        (x=38400). A value of x=0 disables V.110 switching
+                        back to default X.75. This command sets the following
+                        Registers:
+                          Reg 14 (Layer-2 protocol):
+                            x = 0:     0
+                            x = 9600:  7
+                            x = 19200: 8
+                            x = 38400: 9
+                          Reg 18.2 = 1
+                          Reg 19 (Additional Service Indicator):
+                            x = 0:       0
+                            x = 9600:  197
+                            x = 19200: 199
+                            x = 38400: 198
+                          Note on value in Reg 19:
+                            There is _NO_ common convention for 38400 baud.
+                            The value 198 is chosen arbitrarily. Users
+                            _MUST_ negotiate this value before establishing
+                            a connection.
+               AT&Sx    Set window-size (x = 1..8) (not yet implemented)
+               AT&V     Show all settings.
+               AT&W0    Write registers and EAZ/MSN to profile. See also
+                        iprofd (5.c in this README).
+               AT&X0    BTX-mode and T.70-mode off (default)
+               AT&X1    BTX-mode on. (S13.1=1, S13.5=0 S14=0, S16=7, S18=7, S19=0)
+               AT&X2    T.70-mode on. (S13.1=1, S13.5=1, S14=0, S16=7, S18=7, S19=0)
+               AT+Rx    Resume a suspended call with CallID x (x = 1,2,3...)
+               AT+Sx    Suspend a call with CallID x (x = 1,2,3...)
+
+           For voice-mode commands refer to README.audio
+
+           1.3.2 Escape sequence:
+               During a connection, the emulation reacts just like
+               a normal modem to the escape sequence <DELAY>+++<DELAY>.
+               (The escape character - default '+' - can be set in the
+               register 2).
+               The DELAY must at least be 1.5 seconds long and delay
+               between the escape characters must not exceed 0.5 seconds.
+
+           1.3.3 Registers:
+
+              Nr.  Default  Description
+              0    0        Answer on ring number.
+                            (no auto-answer if S0=0).
+              1    0        Count of rings.
+              2    43       Escape character.
+                            (a value >= 128 disables the escape sequence).
+              3    13       Carriage return character (ASCII).
+              4    10       Line feed character (ASCII).
+              5    8        Backspace character (ASCII).
+              6    3        Delay in seconds before dialing.
+              7    60       Wait for carrier.
+              8    2        Pause time for comma (ignored)
+              9    6        Carrier detect time (ignored)
+             10    7        Carrier loss to disconnect time (ignored).
+             11    70       Touch tone timing (ignored).
+             12    69       Bit coded register:
+                            Bit 0:    0 = Suppress response messages.
+                                      1 = Show response messages.
+                            Bit 1:    0 = English response messages.
+                                      1 = Numeric response messages.
+                            Bit 2:    0 = Echo off.
+                                      1 = Echo on.
+                            Bit 3     0 = DCD always on.
+                                      1 = DCD follows carrier.
+                            Bit 4     0 = CTS follows RTS
+                                      1 = Ignore RTS, CTS always on.
+                            Bit 5     0 = return to command mode on DTR low.
+                                      1 = Same as 0 but also resets all
+                                          registers.
+                                      See also register 13, bit 2
+                            Bit 6     0 = DSR always on.
+                                      1 = DSR only on if channel is available.
+                            Bit 7     0 = Cisco-PPP-flag-hack off (default).
+                                      1 = Cisco-PPP-flag-hack on.
+             13   0         Bit coded register:
+                            Bit 0:    0 = Use delayed tty-send-algorithm
+                                      1 = Direct tty-send.
+                            Bit 1:    0 = T.70 protocol (Only for BTX!) off
+                                      1 = T.70 protocol (Only for BTX!) on
+                            Bit 2:    0 = Don't hangup on DTR low.
+                                      1 = Hangup on DTR low.
+                            Bit 3:    0 = Standard response messages
+                                      1 = Extended response messages
+                            Bit 4:    0 = CALLER NUMBER before every RING.
+                                      1 = CALLER NUMBER after first RING.
+                            Bit 5:    0 = T.70 extended protocol off
+                                      1 = T.70 extended protocol on
+                            Bit 6:    0 = Special RUNG Message off
+                                      1 = Special RUNG Message on
+                                          "RUNG" is delivered on a ttyI, if
+                                          an incoming call happened (RING) and
+                                          the remote party hung up before any
+                                          local ATA was given.
+			    Bit 7:    0 = Don't show display messages from net
+                                      1 = Show display messages from net
+				          (S12 Bit 1 must be 0 too)      
+             14   0         Layer-2 protocol:
+                                      0 = X75/LAPB with I-frames
+                                      1 = X75/LAPB with UI-frames
+                                      2 = X75/LAPB with BUI-frames
+                                      3 = HDLC
+                                      4 = Transparent (audio)
+                                      7 = V.110, 9600 baud
+                                      8 = V.110, 19200 baud
+                                      9 = V.110, 38400 baud
+                                     10 = Analog Modem (only if hardware supports this)
+                                     11 = Fax G3 (only if hardware supports this)
+             15   0         Layer-3 protocol:
+                                      0 = transparent
+                                      1 = transparent with audio features (e.g. DSP)
+                                      2 = Fax G3 Class 2 commands (S14 has to be set to 11)
+                                      3 = Fax G3 Class 1 commands (S14 has to be set to 11)
+             16   250       Send-Packet-size/16
+             17   8         Window-size (not yet implemented)
+             18   4         Bit coded register, Service-Octet-1 to accept,
+                            or to be used on dialout:
+                            Bit 0:    Service 1 (audio) when set.
+                            Bit 1:    Service 5 (BTX) when set.
+                            Bit 2:    Service 7 (data) when set.
+                            Note: It is possible to set more than one
+                                  bit. In this case, on incoming calls
+                                  the selected services are accepted,
+                                  and if the service is "audio", the
+                                  Layer-2-protocol is automatically
+                                  changed to 4 regardless of the setting
+                                  of register 14. On outgoing calls,
+                                  the most significant 1-bit is chosen to
+                                  select the outgoing service octet.
+             19   0         Service-Octet-2
+             20   0         Bit coded register (readonly)
+                            Service-Octet-1 of last call.
+                            Bit mapping is the same as register 18
+             21   0         Bit coded register (readonly)
+                            Set on incoming call (during RING) to
+                            octet 3 of calling party number IE (Numbering plan)
+                            See section 4.5.10 of ITU Q.931
+             22   0         Bit coded register (readonly)
+                            Set on incoming call (during RING) to
+                            octet 3a of calling party number IE (Screening info)
+                            See section 4.5.10 of ITU Q.931
+             23   0         Bit coded register:
+                            Bit 0:    0 = Add CPN to RING message off
+                                      1 = Add CPN to RING message on
+                            Bit 1:    0 = Add CPN to FCON message off
+                                      1 = Add CPN to FCON message on
+                            Bit 2:    0 = Add CDN to RING/FCON message off
+                                      1 = Add CDN to RING/FCON message on
+
+  Last but not least a (at the moment fairly primitive) device to request
+  the line-status (/dev/isdninfo) is made available.
+
+  Automatic assignment of devices to lines:
+
+  All inactive physical lines are listening to all EAZs for incoming
+  calls and are NOT assigned to a specific tty or network interface.
+  When an incoming call is detected, the driver looks first for a network
+  interface and then for an opened tty which:
+
+  1. is configured for the same EAZ.
+  2. has the same protocol settings for the B-channel.
+  3. (only for network interfaces if the security flag is set)
+     contains the caller number in its access list.
+  4. Either the channel is not bound exclusively to another Net-interface, or
+     it is bound AND the other checks apply to exactly this interface.
+     (For usage of the bind-features, refer to the isdnctrl-man-page)
+
+  Only when a matching interface or tty is found is the call accepted
+  and the "connection" between the low-level-layer and the link-level-layer
+  is established and kept until the end of the connection.
+  In all other cases no connection is established. Isdn4linux can be
+  configured to either do NOTHING in this case (which is useful, if
+  other, external devices with the same EAZ/MSN are connected to the bus)
+  or to reject the call actively. (isdnctrl busreject ...)
+
+  For an outgoing call, the inactive physical lines are searched.
+  The call is placed on the first physical line, which supports the
+  requested protocols for the B-channel. If a net-interface, however
+  is pre-bound to a channel, this channel is used directly.
+
+  This makes it possible to configure several network interfaces and ttys
+  for one EAZ, if the network interfaces are set to secure operation.
+  If an incoming call matches one network interface, it gets connected to it.
+  If another incoming call for the same EAZ arrives, which does not match
+  a network interface, the first tty gets a "RING" and so on.
+
+2 System prerequisites:
+
+  ATTENTION!
+
+  Always use the latest module utilities. The current version is
+  named in Documentation/Changes. Some old versions of insmod
+  are not capable of setting the driver-Ids correctly.
+
+3. Lowlevel-driver configuration.
+
+   Configuration depends on how the drivers are built. See the
+   README.<yourDriver> for information on driver-specific setup.
+
+4. Device-inodes
+
+   The major and minor numbers and their names are described in
+   Documentation/devices.txt. The major numbers are:
+
+     43 for the ISDN-tty's.
+     44 for the ISDN-callout-tty's.
+     45 for control/info/debug devices.
+
+5. Application
+
+   a) For some card-types, firmware has to be loaded into the cards, before
+      proceeding with device-independent setup. See README.<yourDriver>
+      for how to do that.
+
+   b) If you only intend to use ttys, you are nearly ready now.
+
+   c) If you want to have really permanent "Modem"-settings on disk, you
+      can start the daemon iprofd. Give it a path to a file at the command-
+      line. It will store the profile-settings in this file every time
+      an AT&W0 is performed on any ISDN-tty. If the file already exists,
+      all profiles are initialized from this file. If you want to unload
+      any of the modules, kill iprofd first.
+
+   d) For networking, continue: Create an interface:
+       isdnctrl addif isdn0
+
+   e) Set the EAZ (or MSN for Euro-ISDN):
+       isdnctrl eaz isdn0 2
+
+     (For 1TR6 a single digit is allowed, for Euro-ISDN the number is your
+      real MSN e.g.: Phone-Number)
+
+   f) Set the number for outgoing calls on the interface:
+       isdnctrl addphone isdn0 out 1234567
+       ... (this can be executed more than once, all assigned numbers are
+            tried in order)
+      and the number(s) for incoming calls:
+       isdnctrl addphone isdn0 in 1234567
+
+   g) Set the timeout for hang-up:
+       isdnctrl huptimeout isdn0 <timeout_in_seconds>
+
+   h) additionally you may activate charge-hang-up (= Hang up before
+      next charge-info, this only works, if your isdn-provider transmits
+      the charge-info during and after the connection):
+       isdnctrl chargehup isdn0 on
+
+   i) Set the dial mode of the interface:
+       isdnctrl dialmode isdn0 auto
+      "off" means that you (or the system) cannot make any connection
+        (neither incoming or outgoing connections are possible). Use
+        this if you want to be sure that no connections will be made.
+      "auto" means that the interface is in auto-dial mode, and will
+        attempt to make a connection whenever a network data packet needs
+        the interface's link. Note that this can cause unexpected dialouts,
+        and lead to a high phone bill! Some daemons or other pc's that use
+        this interface can cause this.
+        Incoming connections are also possible.
+      "manual" is a dial mode created to prevent the unexpected dialouts.
+        In this mode, the interface will never make any connections on its
+        own. You must explicitly initiate a connection with "isdnctrl dial
+        isdn0". However, after an idle time of no traffic as configured for
+	the huptimeout value with isdnctrl, the connection _will_ be ended.
+	If you don't want any automatic hangup, set the huptimeout value to 0.
+        "manual" is the default.
+
+   j) Setup the interface with ifconfig as usual, and set a route to it.
+
+   k) (optional) If you run X11 and have Tcl/Tk-wish version 4.0, you can use
+     the script tools/tcltk/isdnmon. You can add actions for line-status
+     changes. See the comments at the beginning of the script for how to
+     do that. There are other tty-based tools in the tools-subdirectory
+     contributed by Michael Knigge (imon), Volker Götz (imontty) and
+     Andreas Kool (isdnmon).
+
+   l) For initial testing, you can set the verbose-level to 2 (default: 0).
+      Then all incoming calls are logged, even if they are not addressed
+      to one of the configured net-interfaces:
+      isdnctrl verbose 2
+
+  Now you are ready! A ping to the set address should now result in an
+  automatic dial-out (look at syslog kernel-messages).
+  The phone numbers and EAZs can be assigned at any time with isdnctrl.
+  You can add as many interfaces as you like with addif following the
+  directions above. Of course, there may be some limitations. But we have
+  tested as many as 20 interfaces without any problem. However, if you
+  don't give an interface name to addif, the  kernel will assign a name
+  which starts with "eth". The number of "eth"-interfaces is limited by
+  the kernel.
+
+5. Additional options for isdnctrl:
+
+   "isdnctrl secure <InterfaceName> on"
+   Only incoming calls, for which the caller-id is listed in the access
+   list of the interface are accepted. You can add caller-id's With the
+   command "isdnctrl addphone <InterfaceName> in <caller-id>"
+   Euro-ISDN does not transmit the leading '0' of the caller-id for an
+   incoming call, therefore you should configure it accordingly.
+   If the real number for the dialout e.g. is "09311234567" the number
+   to configure here is "9311234567". The pattern-match function
+   works similar to the shell mechanism.
+
+     ?     one arbitrary digit
+     *     zero or arbitrary many digits
+     [123] one of the digits in the list
+     [1-5] one digit between '1' and '5'
+           a '^' as the first character in a list inverts the list
+
+
+   "isdnctrl secure <InterfaceName> off"
+   Switch off secure operation (default).
+
+   "isdnctrl ihup <InterfaceName> [on|off]"
+   Switch the hang-up-timer for incoming calls on or off.
+
+   "isdnctrl eaz <InterfaceName>"
+   Returns the EAZ of an interface.
+
+   "isdnctrl delphone <InterfaceName> in|out <number>"
+   Deletes a number from one of the access-lists of the interface.
+
+   "isdnctrl delif <InterfaceName>"
+   Removes the interface (and possible slaves) from the kernel.
+   (You have to unregister it with "ifconfig <InterfaceName> down" before).
+
+   "isdnctrl callback <InterfaceName> [on|off]"
+   Switches an interface to callback-mode. In this mode, an incoming call
+   will be rejected and after this the remote-station will be called. If
+   you test this feature by using ping, some routers will re-dial very
+   quickly, so that the callback from isdn4linux may not be recognized.
+   In this case use ping with the option -i <sec> to increase the interval
+   between echo-packets.
+
+   "isdnctrl cbdelay <InterfaceName> [seconds]"
+   Sets the delay (default 5 sec) between an incoming call and start of
+   dialing when callback is enabled.
+
+   "isdnctrl cbhup <InterfaceName> [on|off]"
+   This enables (default) or disables an active hangup (reject) when getting an
+   incoming call for an interface which is configured for callback.
+
+   "isdnctrl encap <InterfaceName> <EncapType>"
+   Selects the type of packet-encapsulation. The encapsulation can be changed
+   only while an interface is down.
+
+   At the moment the following values are supported:
+
+   rawip    (Default) Selects raw-IP-encapsulation. This means, MAC-headers
+            are stripped off.
+   ip       IP with type-field. Same as IP but the type-field of the MAC-header
+            is preserved.
+   x25iface X.25 interface encapsulation (first byte semantics as defined in
+            ../networking/x25-iface.txt). Use this for running the linux
+            X.25 network protocol stack (AF_X25 sockets) on top of isdn.
+   cisco-h  A special-mode for communicating with a Cisco, which is configured
+            to do "hdlc"
+   ethernet No stripping. Packets are sent with full MAC-header.
+            The Ethernet-address of the interface is faked, from its
+            IP-address: fc:fc:i1:i2:i3:i4, where i1-4 are the IP-addr.-values.
+   syncppp  Synchronous PPP
+
+   uihdlc   HDLC with UI-frame-header (for use with DOS ISPA, option -h1)
+
+
+   NOTE:    x25iface encapsulation is currently experimental. Please
+            read README.x25 for further details
+
+
+   Watching packets, using standard-tcpdump will fail for all encapsulations
+   except ethernet because tcpdump does not know how to handle packets
+   without MAC-header. A patch for tcpdump is included in the utility-package
+   mentioned above.
+
+   "isdnctrl l2_prot <InterfaceName> <L2-ProtocolName>"
+   Selects a layer-2-protocol.
+   (With the ICN-driver and the HiSax-driver, "x75i" and "hdlc" is available.
+   With other drivers, "x75ui", "x75bui", "x25dte", "x25dce" may be
+   possible too. See README.x25 for x25 related l2 protocols.)
+
+   isdnctrl l3_prot <InterfaceName> <L3-ProtocolName>
+   The same for layer-3. (At the moment only "trans" is allowed)
+
+   "isdnctrl list <InterfaceName>"
+   Shows all parameters of an interface and the charge-info.
+   Try "all" as the interface name.
+
+   "isdnctrl hangup <InterfaceName>"
+   Forces hangup of an interface.
+
+   "isdnctrl bind <InterfaceName> <DriverId>,<ChannelNumber> [exclusive]"
+   If you are using more than one ISDN card, it is sometimes necessary to
+   dial out using a specific card or even preserve a specific channel for
+   dialout of a specific net-interface. This can be done with the above
+   command. Replace <DriverId> by whatever you assigned while loading the
+   module. The <ChannelNumber> is counted from zero. The upper limit
+   depends on the card used. At the moment no card supports more than
+   2 channels, so the upper limit is one.
+
+   "isdnctrl unbind <InterfaceName>"
+   unbinds a previously bound interface.
+
+   "isdnctrl busreject <DriverId> on|off"
+   If switched on, isdn4linux replies a REJECT to incoming calls, it
+   cannot match to any configured interface.
+   If switched off, nothing happens in this case.
+   You normally should NOT enable this feature, if the ISDN adapter is not
+   the only device connected to the S0-bus. Otherwise it could happen that
+   isdn4linux rejects an incoming call, which belongs to another device on
+   the bus.
+
+   "isdnctrl addslave <InterfaceName> <SlaveName>
+   Creates a slave interface for channel-bundling. Slave interfaces are
+   not seen by the kernel, but their ISDN-part can be configured with
+   isdnctrl as usual. (Phone numbers, EAZ/MSN, timeouts etc.) If more
+   than two channels are to be bundled, feel free to create as many as you
+   want. InterfaceName must be a real interface, NOT a slave. Slave interfaces
+   start dialing, if the master interface resp. the previous slave interface
+   has a load of more than 7000 cps. They hangup if the load goes under 7000
+   cps, according to their "huptimeout"-parameter.
+
+   "isdnctrl sdelay <InterfaceName> secs."
+   This sets the minimum time an Interface has to be fully loaded, until
+   it sends a dial-request to its slave.
+
+   "isdnctrl dial <InterfaceName>"
+   Forces an interface to start dialing even if no packets are to be
+   transferred.
+
+   "isdnctrl mapping <DriverId> MSN0,MSN1,MSN2,...MSN9"
+   This installs a mapping table for EAZ<->MSN-mapping for a single line.
+   Missing MSN's have to be given as "-" or can be omitted, if at the end
+   of the commandline.
+   With this command, it's now possible to have an interface listening to
+   mixed 1TR6- and Euro-Type lines. In this case, the interface has to be
+   configured to a 1TR6-type EAZ (one digit). The mapping is also valid
+   for tty-emulation. Seen from the interface/tty-level the mapping
+   CAN be used, however it's possible to use single tty's/interfaces with
+   real MSN's (more digits) also, in which case the mapping will be ignored.
+   Here is an example:
+
+   You have a 1TR6-type line with base-nr. 1234567 and a Euro-line with
+   MSN's 987654, 987655 and 987656. The DriverId for the Euro-line is "EURO".
+
+   isdnctrl mapping EURO -,987654,987655,987656,-,987655
+   ...
+   isdnctrl eaz isdn0 1      # listen on 12345671(1tr6) and 987654(euro)
+   ...
+   isdnctrl eaz isdn1 4      # listen on 12345674(1tr6) only.
+   ...
+   isdnctrl eaz isdn2 987654 # listen on 987654(euro) only.
+
+   Same scheme is used with AT&E...  at the tty's.
+
+6. If you want to write a new low-level-driver, you are welcome.
+   The interface to the link-level-module is described in the file INTERFACE.
+   If the interface should be expanded for any reason, don't do it
+   on your own, send me a mail containing the proposed changes and
+   some reasoning about them.
+   If other drivers will not be affected, I will include the changes
+   in the next release.
+   For developers only, there is a second mailing-list. Write to me
+   (fritz@isdn4linux.de), if you want to join that list.
+
+Have fun!
+
+ -Fritz
+