Asterisk ss7 channels

SS7 Channel driver by Netfors (formerly Dicea)

This page describes chan_ss7, an Asterisk channel driver for SS7 on dahdi/zaptel E1 interfaces.
The license for chan_ss7 is GPL, and chan_ss7 is not certified.

Major features include:
  • MTP2 (Q.703) implementation (mostly complete).
  • MTP3 (Q.704) implementation (bare essentials).
  • ISUP (Q.76x) implementation (large subset). details
  • Supports Redfone/Openvox/Digium/Sangoma E1 (T1 and other zap-compatible cards should be easy to add).
  • Supports incoming and outgoing audio/video calls (video with H324M).
  • Supports full ALAW audio (ULAW should be easy to add). Jitter Buffer support.
  • Facilities for raw MTP2 packet dump, suitable for Ethereal debugging.
  • Supports high call volumes; tested with 120 simultaneous calls, but should handle much more than that, depending on transcoding etc.
  • Supports multiple linksets with different DPCs
  • Supports linksets with multiple links.
  • Supports load sharing and MTP changeover.
  • Support for STP signalling
  • Supports multiple hosts (cluster) configuration with load sharing and failover.
  • Flexible Dial command syntax for SS7 to allow use on linksets, e.g. Dial(SS7/linkset1/12345678)
  • Compatible with asterisk 1.2.x, 1.4.x., 1.6.x., 1.8.x

The chan_ss7 code was developed by Sifira A/S for internal use, but it is being released as GPL in the hope that others will benefit from it and will want to contribute to the further development of the code. Active development is by (formerly now

The source code may be downloaded from this download page.


DEVEL VERSION NO (23.3.2009)


Usage: svn co

To move an SVN checkout from the former Dicea SVN repository to the new Netfors repository, use:

svn switch --relocate <directory>, where <directory> is the local working directory.


There is a quick setup guide with a step-by-step explanation on how to set up chan_ss7 between two asterisk boxes, in effect creating a private SS7 network for test. This should enable interested people to start playing with the module, and also serve as a start for anyone trying to connect chan_ss7 to other SS7 equipment.

Feedback, patches, and questions may be sent to

Additional documentation for chan_ss7


  • CRBT
  • continuity check from CLI
  • change configuration without Asterisk restart
  • ss7 cause 0 fix
  • asterisk 10 compatibility
  • port patches form (0.9) to actual version


See also

Go back to Asterisk ss7

HITS: 132986
Created by: knielsen, Last modification: Wed 27 of Nov, 2013 (20:52 UTC) by khaamooshi
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