isdnctrl(8) Linux System Administration isdnctrl(8)
isdnctrl - get/set ISDN device information
isdnctrl action device ...
isdnctrl is used to create and delete network interfaces for ISDN, set
up the various parameters and phone numbers for dial in and dial out.
It is also used to list the current parameters of an already configured
network interface. isdnctrl is not needed for configuration of ISDN
The use of isdnctrl is independent of the hardware driver.
The following actions may be given to isdnctrl.
Adds a new ISDN interface name to the kernel. If name is omit-
ted, the kernel will use ethX, where X is an increasing number
starting from 0. This is probably not useful with ISDN so using
a name like isdn0 (for raw ip interfaces) or ippp0 (for syn-
chronous PPP interfaces) is always recommended.
delif name [force]
Removes the ISDN interface name from the kernel. If the optional
keyword force is appended, isdnctrl executes ifconfig name down
before removing it.
Removes all ISDN interfaces from the kernel if it is possible.
If the optional keyword force is appended, isdnctrl executes
ifconfig name down before removing an interface.
resets the interface name to some reasonable defaults.
dialmode name [off|manual|auto]
Sets the dial mode of the interface to one of:
no connection can be made; an existing connection is terminated
immediately. Incoming connections are also not possible.
manual dialing / hangup; a connection will only be made after
isdnctrl dial name but the line will be disconnected after the
huptimeout value set if using kernel drivers updated since 1 Nov
1998; otherwise an explicit isdnctrl hangup name will be needed
to cause the connection to be dropped.
Incoming connections are possible; however, if this interface is
configured in callback in mode, the callback dial will not hap-
pen (as this is actually an outgoing connection, not an incoming
autodial mode; an outgoing packet will trigger a dialout, and a
hangup will occur after the huptimeout value specified (see
An interface in auto dial mode will call another system back (if
configured in callback in mode).
auto was the "old" behaviour (as it was before dialmode was
If no argument is given, the current dialmode value is dis-
You can give all as the interface name; the command will then be
executed for all interfaces.
addphone name out num
Adds the phone number num to the list of outgoing numbers of the
ISDN interface name. Numbers in this list are used to dial the
remote station if the connection is down and packets are to be
sent via the interface (Dial on demand). More than one number
can be set by calling isdnctrl addphone repeatedly. If more than
one number is set, these will be tried one after another (the
last added number is tried first, etc.). When using a german
SPV-type connection, the number has to be prefixed by a capital
addphone name in num
Adds the phone number num to the list of incoming numbers of the
ISDN interface name. Numbers in this list are used to verify
access permission of the remote station if an incoming call is
received. The verification can be disabled by setting the inter-
face into insecure mode using isdnctrl name secure off. If the
list is empty, incoming calls are disabled. More than one num-
ber can be added by calling isdnctrl addphone repeatedly. Also
wildcards can be used (see below).
delphone name in|out num
Removes phone number num from the incoming or outgoing phone
eaz name [num]
Set the EAZ (German 1TR6 protocol) or MSN (Euro-ISDN E-DSS1) for
ISDN interface name to num. For an EAZ this is only one digit,
while for an MSN num is the whole MSN (usually the local phone
number). If num is omitted, isdnctrl prints the current setting
for ISDN interface name.
huptimeout name [seconds]
Set the hangup timeout for ISDN interface name to seconds. If
there is inactivity (i.e. no traffic on the interface) for the
given time the driver automatically shuts down the connection.
If seconds is omitted isdnctrl prints the current setting for
cbdelay name [seconds]
Set the callback delay for ISDN interface name to seconds. If
callback mode for this interface is in, dialing is delayed the
given time. If the callback mode is out, after dialing out and
waiting the given time, a hangup is issued to free the line for
the incoming callback from the remote machine. This hangup-
after-dial is disabled by setting cbdelay to 0. If seconds is
omitted isdnctrl prints the current setting for interface name.
dialmax name [num]
Set the number of dial attempts for ISDN interface name to num.
If dialing, each phone number is tried this many times before
giving up. If num is omitted isdnctrl prints the current set-
ting for interface name.
ihup name [on|off]
Turn on or off the hangup timeout for incoming calls on inter-
face name. If on or off is omitted the current setting is
chargehup name [on|off]
Turn on or off hangup before next charge info for interface
name. This can only be used if the ISDN provider transmits
charge info during and after the connection. If set to on, the
driver will close the connection just before the next charge
info will be received if the interface is inactive. If on or off
is omitted the current setting is printed.
chargeint name [seconds]
If seconds are given, the charge interval for the given inter-
face is set. This may be useful on ISDN lines with no chargeinfo
or no online chargeinfo. The connection will be closed 2 seconds
before the end of the next estimated charge interval if huptime-
out seconds of inactivity have been reached. If ihup is on,
incoming connections are closed by this mechanism also. On
lines with online charge info you also might ask by chargeint
name for the current charge interval as delivered from the tele-
com on a given interface.
secure name [on|off]
Turns on or off the security feature for interface name. If set
to on, incoming calls will only be accepted if the calling num-
ber can be found in the incoming access list. See description of
action addphone for information about how to add numbers to this
list. If on or off is omitted, the current setting is printed.
callback name [mode]
Set callback mode for interface name to mode mode. If callback
mode is in, then after getting an incoming call, a callback is
triggered. If callback mode is out, then the local system does
the initial call and then waits for callback of the remote
machine. The option on is available only for compatibility with
older versions. Its meaning is the same like in. If callback
mode is off, calls are handled normally without special process-
cbhup name [on|off]
Turns on or off Hangup (Reject) for interface name before start-
ing callback. If cbhup is on, when receiving an incoming call,
the interface first rejects that call before the callback
sequence is started. If on or off is omitted, the current set-
ting is printed.
encap name [encapsulation]
Set the encapsulation mode for interface name. Possible encap-
raw ip encapsulation (default)
IP + typefield encapsulation
Special mode for communicating with a Cisco in HDLC-mode with
Cisco-keepalive switched off.
ethernet over ISDN (MAC-header included)
Synchronous PPP over ISDN
raw ip with additional ui-header
Special mode for communicating with a Cisco in HDLC-mode with
Cisco-keepalive switched on.
Provides an interface as required by the Linux X.25 PLP protocol
implementation (requires Linux 2.1.x or newer).
If encapsulation is omitted, the current setting is printed.
l2_prot name [protocol]
Set the layer-2 protocol for interface name. Possible values
for protocol are:
x75i, x75ui, x75bui and hdlc. If protocol is omitted the cur-
rent setting is printed.
l3_prot name [ protocol ]
Set the layer-3 protocol for interface name. At the moment only
trans is supported here. If protocol is omitted the current
setting is printed.
List all parameters and the charge info for interface name. If
name is all, then all interfaces are listed.
Show the connection status for interface name. The output can
be one of the following types:
ippp0 not connected
There is no connection
ippp0 connected to 0123456789
There is an outgoing connection to phone number 0123456789
ippp0 connected from 0123456789
There is an incoming connection from phone number 0123456789
If the interface is connected, the exit status of the command is true,
else it is false.
If name is all, then the connection status for all interfaces is shown.
The exit status is always true in this case.
If name is active, then only those interfaces that are currently con-
nected are shown. The exit status is always true in this case.
Set verbosity level to num.
The connection of interface name is closed immediately.
bind name driverId,channel [exclusive]
Binds an interface name to a physical channel. The driverId
identifies a specific S0-Port. The channels of a port start
counting with zero. If exclusive is given, other interfaces can-
not use that channel anymore. Otherwise, the channel may be
used by other interfaces.
Unbinds a the previously bound interface name.
pppbind name [num]
Binds the interface name to an ippp device /dev/ipppnum. This
works only for synchronous ppp. The value must be a number. If
num is omitted and name is called ipppX , then the interface is
bound to /dev/ipppX.
Unbinds the previously bound interface name.
busreject driverId [on|off]
If switched on, instead of ignoring incoming calls not matching
any interface, isdn4linux responds with a REJECT to those calls.
If switched off, isdn4linux is passive, allowing other devices
connected to the same S0-bus to answer the call. You normally
should not enable this feature, if the ISDN adaptor 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.
addslave name slave
Adds a slave interface named slave to interface name for raw
channel-bundling. For bundling of more than two channels, any
number of slaves can be added to an interface by using this com-
mand repeatedly. name must refer to an existing "master" inter-
face (not a slave). Slave interfaces are not visible to the ker-
nel, however all usual ISDN settings can be configured. Because
slave interfaces are not visible to the kernel, they are config-
ured "through" their "master", so it is important that slave
interfaces are added before the corresponding "master" is
started by ifconfig. If the "master" is already up, it has to
be shutdown with ifconfig down ... otherwise the addslave com-
mand will be rejected.
sdelay name num
Set delay for slave-dialing. The master interface name has to
have a load of more than trigger cps for at least num seconds,
before its slave starts dialing.
Note that this only works for rawIP, not MPPP!
trigger name num
Set trigger level for slave-dialing. The master interface name
has to have a load of more than num cps for at least sdelay sec-
onds, before its slave starts dialing.
Note that this only works for rawIP, not MPPP!
For MPPP, this adds a slave interface to the existing connec-
tion, i.e. connect the extra channel now. It is like a dial com-
mand for the extra channel.
This also means that addlink will only work if the master inter-
face name must already be connected! Also, the dialmode for the
slave interface must be auto.
For MPPP, this removes a slave interface from the existing con-
nection, i.e. hangup the extra channel now.
Force dialing of interface name.
mapping driverId MSN0[,MSN1[,MSN2]] ... [,MSN9]
Installs a mapping-table for MSN<->EAZ-mapping. See README for
Man(1) output converted with