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dahdi_span_types - Man Page

set line modes of DAHDI spans before assignment


dahdi_span_types [options] <list|dumpconfig|set> [devpath ...]


The span type (the line mode: E1/T1/J1) must be set to a span before DAHDI assigns it a span number, as E1 spans use more channels. dahdi_span_types applies the span type configuration to an un-assigned span.

Using it only makes sense when the kernel module parameter dahdi.auto_assign_span is unset, otherwise DAHDI automatically assign span numbers during device registration.

dahdi_span_types takes a command and an optional list of devices. If no device is given, the command is applied to all devices.

The device is marked as a path in the SysFS tree.



Output usage message and exit


During "set" operation, only show what would be done, without actually changing anything.


During "set" operation, show the actions that are being performed.


During "dumpconfig" operation, force special generation mode:

  • First, generates a "wildcard" entry with the fiven line-mode.
  • Comment out all span entries. Each of them may be manually un-commented to override the "wildcard".



Reads settings from span-types.conf and applies them to the device(s) specified in the command line (or all devices, if none specified).


List line modes for all spans in the system which may be set with dahdi_span_types (E1/T1/J1 spans).


List types for the spans in a format fit to be used in span-types.conf. Use this to generate a configuration file after you have (perhaps manually) set all existing spans.

dahdi_genconf spantypes uses this command internally.


General structure

span-types.conf is a file with lines specifying line modes of spans.

Empty lines or lines beginning with '#' are ignored.

Each line is in the format of:

ID spanspec ...

The ID field specifies the DAHDI device and the spanspecs define the line modes of its spans. A line may have multiple spanspecs in a single line (though dumpconfig generates a configuration with one per line).

Span Identifier

A DAHDI device may be specified either by a hardware identifier (a software readable serial number or whatever) or the location in which it is installed on the system. The former makes it simpler to change connector / slot whereas the latter makes it simpler to replace a unit.

The value in this field is matched (when the command set is used) to the following values:


See above for their descriptions. The value may include shell wildcards: *, ? and [], which are used in the match. The values to be matched are first cleaned up: '!' is replaced with '/' and any character not in "a-zA-Z0-9/:.-" is replaced by "_".

Note that while span-types.conf allows an arbitrarily-complex combination of E1, J1 and T1 ports, it would normally have just a single wildcard line setting the line mode (the first line in the example below).

Span Specification

Each line should have one or more span specifications: this is the value used to set span type with DAHDI in the SysFS interface. A specification has two colon-separated fields:


for instance, the following are four span specifications specify ports 1 and 2 as E1 and ports 3 and 4 as T1: [12]:E1 [34]:T1 .


The relative number of the span in the device. E.g.: port number. This field may contain shell wildcards (*, ? and [])



Multiple matches

During set operation, the dahdi_span_types applies all matching settings to a span. This is done in the order of lines in the configuration files.

Thus, if there are multiple matches to a span -- the last match will win (all will be applied to the kernel in order. The last one in the file will be applied last).


*             *:T1      # All spans on all devices will be T1
usb:X1234567  [34]:E1   # Except spans 3,4 on the device which will be E1



The directory in which span-types.conf resides. /etc/dahdi if not overridden from the environment.


The path to span-types.conf resides. /etc/dahdi/span-types.conf if not overridden from the environment.



The default location for the configuration file.


SysFS node for the device. In this directory reside the following files, among others:


read/write file. Reading from it returns current configuration for spans of the device. Span-specifications can be written to it to change line modes (but only for a span that is not assigned yet).

See Also

dahdi_span_assignments(8), dahdi_genconf(8), dahdi_cfg(8)


dahdi_span_types was written by Oron Peled.  This manual page was written by Tzafrir Cohen. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 any  later version published by the Free Software Foundation.

Referenced By


23 Jan 2014