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+The isdn diversion services are a supporting module working together with
+the isdn4linux and the HiSax module for passive cards. 
+Active cards, TAs and cards using a own or other driver than the HiSax 
+module need to be adapted to the HL<->LL interface described in a separate 
+document. The diversion services may be used with all cards supported by 
+the HiSax driver.
+The diversion kernel interface and controlling tool divertctrl were written
+by Werner Cornelius (werner@isdn4linux.de or werner@titro.de) under the
+GNU General Public License.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+Table of contents
+=================
+
+1. Features of the i4l diversion services 
+   (Or what can the i4l diversion services do for me)
+
+2. Required hard- and software
+
+3. Compiling, installing and loading/unloading the module  
+   Tracing calling and diversion information 
+
+4. Tracing calling and diversion information
+ 
+5. Format of the divert device ASCII output
+ 
+
+1. Features of the i4l diversion services 
+   (Or what can the i4l diversion services do for me)
+
+   The i4l diversion services offers call forwarding and logging normally 
+   only supported by isdn phones. Incoming calls may be diverted 
+   unconditionally (CFU), when not reachable (CFNR) or on busy condition 
+   (CFB). 
+   The diversions may be invoked statically in the providers exchange
+   as normally done by isdn phones. In this case all incoming calls
+   with a special (or all) service identifiers are forwarded if the 
+   forwarding reason is met. Activated static services may also be 
+   interrogated (queried).
+   The i4l diversion services additionally offers a dynamic version of
+   call forwarding which is not preprogrammed inside the providers exchange
+   but dynamically activated by i4l.
+   In this case all incoming calls are checked by rules that may be
+   compared to the mechanism of ipfwadm or ipchains. If a given rule matches
+   the checking process is finished and the rule matching will be applied
+   to the call.
+   The rules include primary and secondary service identifiers, called 
+   number and subaddress, callers number and subaddress and whether the rule
+   matches to all filtered calls or only those when all B-channel resources
+   are exhausted.
+   Actions that may be invoked by a rule are ignore, proceed, reject, 
+   direct divert or delayed divert of a call.
+   All incoming calls matching a rule except the ignore rule a reported and
+   logged as ASCII via the proc filesystem (/proc/net/isdn/divert). If proceed
+   is selected the call will be held in a proceeding state (without ringing)
+   for a certain amount of time to let an external program or client decide
+   how to handle the call. 
+            
+
+2. Required hard- and software
+   
+   For using the i4l diversion services the isdn line must be of a EURO/DSS1
+   type. Additionally the i4l services only work together with the HiSax 
+   driver for passive isdn cards. All HiSax supported cards may be used for
+   the diversion purposes.
+   The static diversion services require the provider having static services
+   CFU, CFNR, CFB activated on an MSN-line. The static services may not be 
+   used on a point-to-point connection. Further the static services are only
+   available in some countries (for example germany). Countries requiring the 
+   keypad protocol for activating static diversions (like the netherlands) are
+   not supported but may use the tty devices for this purpose.
+   The dynamic diversion services may be used in all countries if the provider
+   enables the feature CF (call forwarding). This should work on both MSN- and
+   point-to-point lines.
+   To add and delete rules the additional divertctrl program is needed. This
+   program is part of the isdn4kutils package.   
+
+3. Compiling, installing and loading/unloading the module  
+   Tracing calling and diversion information 
+
+
+   To compile the i4l code with diversion support you need to say yes to the 
+   DSS1 diversion services when selecting the i4l options in the kernel 
+   config (menuconfig or config).
+   After having properly activated a make modules and make modules_install all
+   required modules will be correctly installed in the needed modules dirs.
+   As the diversion services are currently not included in the scripts of most
+   standard distributions you will have to add a "insmod dss1_divert" after
+   having loaded the global isdn module.
+   The module can be loaded without any command line parameters.
+   If the module is actually loaded and active may be checked with a 
+   "cat /proc/modules" or "ls /proc/net/isdn/divert". The divert file is 
+   dynamically created by the diversion module and removed when the module is
+   unloaded.
+
+
+4. Tracing calling and diversion information
+ 
+   You also may put a "cat /proc/net/isdn/divert" in the background with the
+   output redirected to a file. Then all actions of the module are logged.
+   The divert file in the proc system may be opened more than once, so in 
+   conjunction with inetd and a small remote client on other machines inside
+   your network incoming calls and reactions by the module may be shown on 
+   every listening machine. 
+   If a call is reported as proceeding an external program or client may 
+   specify during a certain amount of time (normally 4 to 10 seconds) what
+   to do with that call.      
+   To unload the module all open files to the device in the proc system must
+   be closed. Otherwise the module (and isdn.o) may not be unloaded. 
+
+5. Format of the divert device ASCII output
+ 
+   To be done later
+