Based on kernel version 4.9. Page generated on 2016-12-21 14:34 EST.
1 The isdn diversion services are a supporting module working together with 2 the isdn4linux and the HiSax module for passive cards. 3 Active cards, TAs and cards using a own or other driver than the HiSax 4 module need to be adapted to the HL<->LL interface described in a separate 5 document. The diversion services may be used with all cards supported by 6 the HiSax driver. 7 The diversion kernel interface and controlling tool divertctrl were written 8 by Werner Cornelius (email@example.com or firstname.lastname@example.org) under the 9 GNU General Public License. 10 11 This program is free software; you can redistribute it and/or modify 12 it under the terms of the GNU General Public License as published by 13 the Free Software Foundation; either version 2 of the License, or 14 (at your option) any later version. 15 16 This program is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License for more details. 20 21 You should have received a copy of the GNU General Public License 22 along with this program; if not, write to the Free Software 23 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 25 Table of contents 26 ================= 27 28 1. Features of the i4l diversion services 29 (Or what can the i4l diversion services do for me) 30 31 2. Required hard- and software 32 33 3. Compiling, installing and loading/unloading the module 34 Tracing calling and diversion information 35 36 4. Tracing calling and diversion information 37 38 5. Format of the divert device ASCII output 39 40 41 1. Features of the i4l diversion services 42 (Or what can the i4l diversion services do for me) 43 44 The i4l diversion services offers call forwarding and logging normally 45 only supported by isdn phones. Incoming calls may be diverted 46 unconditionally (CFU), when not reachable (CFNR) or on busy condition 47 (CFB). 48 The diversions may be invoked statically in the providers exchange 49 as normally done by isdn phones. In this case all incoming calls 50 with a special (or all) service identifiers are forwarded if the 51 forwarding reason is met. Activated static services may also be 52 interrogated (queried). 53 The i4l diversion services additionally offers a dynamic version of 54 call forwarding which is not preprogrammed inside the providers exchange 55 but dynamically activated by i4l. 56 In this case all incoming calls are checked by rules that may be 57 compared to the mechanism of ipfwadm or ipchains. If a given rule matches 58 the checking process is finished and the rule matching will be applied 59 to the call. 60 The rules include primary and secondary service identifiers, called 61 number and subaddress, callers number and subaddress and whether the rule 62 matches to all filtered calls or only those when all B-channel resources 63 are exhausted. 64 Actions that may be invoked by a rule are ignore, proceed, reject, 65 direct divert or delayed divert of a call. 66 All incoming calls matching a rule except the ignore rule a reported and 67 logged as ASCII via the proc filesystem (/proc/net/isdn/divert). If proceed 68 is selected the call will be held in a proceeding state (without ringing) 69 for a certain amount of time to let an external program or client decide 70 how to handle the call. 71 72 73 2. Required hard- and software 74 75 For using the i4l diversion services the isdn line must be of a EURO/DSS1 76 type. Additionally the i4l services only work together with the HiSax 77 driver for passive isdn cards. All HiSax supported cards may be used for 78 the diversion purposes. 79 The static diversion services require the provider having static services 80 CFU, CFNR, CFB activated on an MSN-line. The static services may not be 81 used on a point-to-point connection. Further the static services are only 82 available in some countries (for example germany). Countries requiring the 83 keypad protocol for activating static diversions (like the netherlands) are 84 not supported but may use the tty devices for this purpose. 85 The dynamic diversion services may be used in all countries if the provider 86 enables the feature CF (call forwarding). This should work on both MSN- and 87 point-to-point lines. 88 To add and delete rules the additional divertctrl program is needed. This 89 program is part of the isdn4kutils package. 90 91 3. Compiling, installing and loading/unloading the module 92 Tracing calling and diversion information 93 94 95 To compile the i4l code with diversion support you need to say yes to the 96 DSS1 diversion services when selecting the i4l options in the kernel 97 config (menuconfig or config). 98 After having properly activated a make modules and make modules_install all 99 required modules will be correctly installed in the needed modules dirs. 100 As the diversion services are currently not included in the scripts of most 101 standard distributions you will have to add a "insmod dss1_divert" after 102 having loaded the global isdn module. 103 The module can be loaded without any command line parameters. 104 If the module is actually loaded and active may be checked with a 105 "cat /proc/modules" or "ls /proc/net/isdn/divert". The divert file is 106 dynamically created by the diversion module and removed when the module is 107 unloaded. 108 109 110 4. Tracing calling and diversion information 111 112 You also may put a "cat /proc/net/isdn/divert" in the background with the 113 output redirected to a file. Then all actions of the module are logged. 114 The divert file in the proc system may be opened more than once, so in 115 conjunction with inetd and a small remote client on other machines inside 116 your network incoming calls and reactions by the module may be shown on 117 every listening machine. 118 If a call is reported as proceeding an external program or client may 119 specify during a certain amount of time (normally 4 to 10 seconds) what 120 to do with that call. 121 To unload the module all open files to the device in the proc system must 122 be closed. Otherwise the module (and isdn.o) may not be unloaded. 123 124 5. Format of the divert device ASCII output 125 126 To be done later