an ISDN based PBX for Linux

Formerly known as "PBX4Linux", Linux-Call-Router is not only a router, it is a real ISDN PBX which interconnects ISDN telephones and ISDN lines. It is possible to connect telephones to a Linux box. It is a pure software solution except for the ISDN cards and telephones. The great benefit is the NT-mode that allows to connect telephones to an ISDN card. Special cards are needed and a little bit of different cabeling. It supports lots of features, that only expensive PBXs have. It include a channel driver that can link LCR to Asterisk PBX.

LCR is open source and under GPL.

The chan_lcr is finished! It turns LCR into an ISDN channel driver for Asterisk PBX.

View the list of features and read the HOWTO for a quick start.
Check the list of most cards that are capable of connecting telephones to it.

LCR can run a GSM network in conjunction with OpenBSC. Refer to the http://bs11-abis.gnumonks.org page for more information on running your own GSM network. A howto will follow.
Go to the download section for package snapshots. Note that the project is still at the beginning, so don't expect a full featured GSM network.

Release V1.7 can be downloaded here. Also use the latest mISDN and mISDNuser snapshot from www.mISDN.org, if you kernel does not support it yet.. Also there is a snapshot of OpenBSC which compiles with LCR, because the API changes from time to time.
For changes check README file inside the source tar.


To be able to run LCR you will need:

A working snapshot of the drivers can be found in the download section.

HFC multiport cards / HFC-E1 cards


mISDN V2.0 <= 2.6.24

You will need to replace drivers/isdn/mISDN/core.c by this file. (Rename it first or change Makefile.)
Get additional tone/announcement sets: (only for fun)


For using the Bluebox with Linux-Call-Router, check this out.


For more info, write to jolly@eversberg.eu. For LCR and mISDN questions refer to the mailing list of the isdn4linux project: https://www.isdn4linux.de/mailman/listinfo/isdn4linux.

Visit the download area for latest release.