divertctrl - set/query ISDN diversion services for (E)DSS1 protocol
divertctrl [wait] command driverid ...
divertctrl is used to de/activate call diversions and query actual
activated diversion rules. The i4l diversion services only work using
the (E)DSS1 D-channel protocol in conjunction with the HiSax passive
card driver. For using the services the global isdn drivers need to be
compiled with support for the diversion services. Additionally the
dss1_divert module has to be loaded. This module doesn’t require nor
support any parameters at load time. After successfully loading the
module an entry /proc/net/isdn/divert should appear in the filesystem.
When called without any parameters the divertctrl program outputs a
short help screen. Otherwise the first parameter needs to be a command
followed by a valid driver id. The command may be preceeded by the
optional wait keyword specifying the program to wait until the desired
command could be completed or failed returning the result via the
exitcode. Otherwise the programm immediately returns after invoking the
desired action which may not be completed at this moment.
For some commands the value "-" may be used as a valid driver id
specifying all available drivers. The driver id is equivalent to the id
parameter specified when loading the HiSax driver for a particular
card. All further parameters are command dependant. The divertctrl
program may only be used with root access for security reasons.
The diversion services for i4l may be used in two independant ways:
1. Static call diversion
First possibility to handle diversions of incoming calls is to use
static diversion provided inside the providers exchange. A static
diversion once activated inside the providers exchange requires no
interaction with i4l. The machine may even be shut down, but the
diversion keeps active until it is explicitely deactivated. The
divertctrl tool allows to set/reset and query such static rules if the
service is supported and has been subscribed at the providers side.
This services are only available in some countries like germany. In
other countries (like the netherlands) keypad control is used to
de/activate such static rules. Static rules may be set/reset and
queried independantly by MSN (multiple subscriber number), basic
service (telephony, digital data, ..) and diversion procedure. Three
diversion procedures are defined in the ETSI specs and may be used with
the i4l diversion services:
CFU (call forward unconditional) is a procedure diverting all incoming
calls unconditionally for the programmed MSN and basic service. The
call will never be announced at your side until CFU is deactivated
CFNR (call forward not reachable) is a procedure diverting all incoming
calls for the programmed MSN and basic service after locally signalling
and waiting a certain timeout period. If the call is not answered
during this timeout period it will be diverted to the new destination.
The timeout period is fixed in the providers exchange and is normally 3
rings (about 12 to 15 seconds).
CFB (call forward busy) is a procedure diverting all incoming calls for
the programmed MSN and basic service when all local resources taking
the call are exhausted and busy.
Commands for handling static call diversions
activate driverid <cfu,cfnr,cfb> msn service destination
Activate a static diversion for the given driver, msn and service
diverting the call to the specified destination. All parameters need to
be supplied, no wildcards are allowed. Only one of the three diversion
procedures cfu, cfnr, cfb must be supplied. The value for the service
may be taken from the table of numeric codes of basic services. The
value 0 specifies all available/subscribed services.
deactivate driverid <cfu,cfnr,cfb> msn service
Deactivate a static diversion for the given driver, msn and service.
All parameters need to be supplied, no wildcards are allowed. Only one
of the three diversion procedures cfu, cfnr, cfb must be supplied. The
value for the service may be taken from the table of numeric codes of
basic services. The value 0 specifies all available/subscribed
interrogate driverid <cfu,cfnr,cfb> [msn] [service]
Query static diversions for the given driver, msn and service. Only one
of the three diversion procedures cfu, cfnr, cfb must be supplied. The
msn and service parameters are optional. The value for the service may
be taken from the table of numeric codes of basic services. The value 0
specifies all available/subscribed services. If msn and/or service
parameters are not specified all matching diversions are reported via
stdout. But it is advisable always to specify all parameters to keep
the list as short as possible. All known providers exchanges refuse to
return diversion lists longer than 256 bytes. In this case an empty
response is generated by the exchange even if there are diversions
2. Dynamic call diversion
Additionally the i4l diversion services offer a more flexible
possibility to control call forwarding. Using the dynamic call
diversion the user has the possibilty to specify rules for call
forwarding by additional criterias. The reaction to an incoming call
may be dependant of MSN, basic service, caller id, local subaddress,
caller subaddress and local resource (busy) state. The parameters may
be specified with wildcards, so that call criterias may be grouped to
match. Additionally the diversion actions may be supplied with a
precise timeout value which is not dependant on any providers defaults.
In order to work, the supplumentary service CD (call deflection) has to
be available and subscribed at the providers exchange. The dynamic
diversion services are fully handled inside your machine, so it must be
powered up and activated for the required purpose. After a successfull
dynamic diversion (so called deflection) no local line resources are
required. The lines are free for further incoming calls.
Dynamic Call deflection is controlled by a rule chain the user has to
supply using the divertctrl program. When an incoming call arrives,
calling data is compared against the rules in the chain. If an incoming
call matches a rule, this rule is taken to execute the desired action.
All following rules are ignored. If there is no rule match the
diversion services simply ignore the call.
Commands for handling dynamic call diversions
Flushes (deletes) all rules for the selected driver. If no driverid is
given or it is specified as wilcard - all rules for all drivers are
removed. It is advisable to call this command first when a complete
new ruleset is to be generated, to avoid conflicts with previous set
appendrule driverid action msn si1 si2 callerid screen delay option
This command appends a single rule at the end of the existing rule
chain. If the call arrives through the desired driver, addresses the
selected msn, si1, si2 and matches the desired callerid and option the
specified action is executed. A value of - may be specified for the
driverid to match the rule for all available drivers. The msn may be
specified with a trailing - wildcard. for example the value 123 only
matches an incoming call to msn 123, but specifying 123- matches all
msn starting with 123 followed by any digits or subaddresses which will
not verified. If only - is specified the rule matches all msn and
subaddresses. If your isdn line supports subaddressing it is advisable
to terminate all msn values with a - because the msn check includes a
possibly available subadress which then may be reported as 123.456 for
msn 123 with subaddresses 456 for example. Subaddressing is a special
DSS1 feature not available in most countries and normally needs to be
specially subscribed. So most people need not to think about it. The
value of si1 represents the numeric code of the desired and checked
basic service for the incoming call. This value may be selected from
the table below or just the value 0 specified for all services to
match. The value of si2 represents an additional service indicator for
high layer compatibilty and is only included for completeness. Just set
it to 0 at the moment. The callerid must match the number of the
caller including the subaddress if available. Again the special
wildcard - may be used to match specific groups of numbers.
Additionally a simple value of 0 may be specified. In this case the
rule will match only calls coming in without a caller indentification.
This will be the case if the caller originates from a network not
supporting callerids or the caller suppressed the identification. The
option parameter may take the values 0 to 2 and specifies whether the
rule applies only during special local busy states. The value of 0
lets the rule be valid during any local busy state. A value of 1 lets
the rule only apply to incoming calls if the call is in a non waiting
state. A value of 2 applies te rule only to such calls which arrive as
waiting. This is normally the case when all local resources (B-
channels) are already in use. If the rule criterias mentioned before
match the incoming call, no following rules will be checked and the
desired action will be executed. The value for the parameter action is
numeric and may take the values 0 to 5 at the moment. A value of 0
lets the call to be ignored. The call will not be reported through the
ascii interface and not checked against any following rules. A value
of 1 will report the call through the ascii interface but no other
action will take place. If the value 2 is specified the call will be
reported through the ascii interface and actively put in a local
proceeding state. This means that the providers exchange is told, that
your side needs more time to check whether the call may be handled and
in which way this will be done. This value only is intended for use
with local or remote client software watching the ascii interface and
deciding what to do. No ringing signal is send to the caller until the
decision has been made or a timeout (typically 5 to 15 seconds) occurs.
An example would be a software which announces the call to a user and
requests the desired action. At the moment a client software is under
development, but still not available, so this value may only be
intersting for programmers which want to write their own client. If
value of 4 is specified the call will be actively rejected. The value
of 5 is not primary an diversion function and allows an i4l network
device to be started for dialing out when the rule matches. The
destination number parameter specifies the network device (for example
ippp0) to e dialed. The incoming call itself is not accepted. The
values from 0-2 and 4 don’t require a destination number to be
specified, as the incoming call will not be deflected in this cases.
The last, but most interesting value for most people will be the value
3. Specifying it, will let the call to be deflected/diverted actively.
For this reason additional parameters are taken for interpretation.
First of all destnumber specifies the final number the call should be
diverted to. The parameter delay specifies after how many seconds the
call will be diverted towards the new destination. A value of 0
deflects the call immediately like the cfu in static diversons, any
other value first announces the caller a ringing state until the time
is elapsed and then the call will be diverted like in static cfnr.
During the ringing phase every other device on your line may pick up
the call of course. The value of the parameter screen may take the
values 0 to 2 and specifies if the diversion is presented to the
caller. A value of 0 denies to show the caller that and where the call
has been deflected. Specifying a value of 1 only shows that the call
has been diverted but doesn’t show to which final destination this will
happen. A value of 2 lets the caller know all information of the
diversion (fact of diversion and number diverted to).
insertrule driverid action msn si1 si2 callerid screen delay option
This command inserts a single rule at the beginning before the first
already existing rule in the chain. All parameters and descriptions
are the same as for the appendrule command.
Numeric codes of basic services
0 all services
2 unrestricted digital information
3 audio 3.1 kHz
4 unrestricted digital info with tone announcements
32 telephony 3.1 kHz
34 telefax group 4 class 1
35 videotex syntax based
37 telefax group 2/3
38 telephony 7 kHz
40 filetransfer and access management
42 audio graphic conference
When diversion of speech calls is desired at least services 1, 2 and 32
should be specified.
Interfacing to other programs
The /proc/net/isdn/divert device may be used for debug purposes or
interfacing the diversion services to other programs. It may be
multiple opened. All operations as well as incoming calls may be
watched reading the ascii output of the interface. One possible
application would be a remote client announcing and logging incoming
calls and diversion actions inside the local network. Such logging
service could be invoked via inetd.
With some commands an explicit driverid needs to be specified under
certain conditions even if wildcards should be allowed. If you get a
core dump using wildcards try to use a cmd line specifying a single
interface. This man page is still not complete.
Werner Cornelius <firstname.lastname@example.org or email@example.com>