Cellular Network Infrastructure » cni-legacy » OpenBSC

'''OpenBSC''' is the current name for a software program that started with the name bs11-abis.

What is OpenBSC
It is a [wiki:BSC] (Base Station Controller) side implementation of the A-bis protocol, as implemented in the GSM Technical Specification 08.5x and 12.21. It implements a minimal subset of the [wiki:BSC], [wiki:MSC] and [wiki:HLR]. It does not implement ant of the interfaces (like the A and B interfaces) between the higher-order GSM network components.

The goal of the project is to * provide a basis for experimentation and security research with GSM from the network side * document, publicized and point out any security related issues that we find as part of that * learn more about GSM networks on a lower level, particularly the practical aspects with real-world equipment

We '''are not interested''' in * building a stable/reliable BSC/MSC for deployment in actual networks * building something that follows the GSM spec to the last detail * disrupting actual commercial GSM network

Requirements

OpenBSC runs only on Linux systems and requires a [wiki:E1] interface card compatible with [wiki:mISDN]

It requires a GSM [wiki:BTS]. The only currently tested configuration is with a Siemens [wiki:BS-11] microBTS.

Source code

You can check out the source code via {{{
svn checkout http://bs11-abis.gnumonks.org/svn/trunk/openbsc
}}}
or browse it at http://bs11-abis.gnumonks.org/trac/browser

Mailing list

There's a developer mailing list called openbsc@lists.gnumonks.org
Subscription is available at [http://lists.gnumonks.org/mailman/listinfo/openbsc/]

Project status

=== Things that work === * [wiki:OML] Initialization of the BTS * [wiki:RSL] bringup, channel allocation, Channel required / Immediate Assign * Very simplistic [wiki:HLR] implemented as sqlite database * Non-secure Authentication using [wiki:IMEI]/[wiki:IMSI] and regular SIM cards. * [wiki:IMEI]/[wiki:IMSI] skimming of all phones that try to register with OpenBSC * [wiki:SMS] reception and [wiki:SMS] sending (simplistic, not possible to route them yet) * Transmission of MM INFO packets with operator name and local time / timezone * Extremely simplistic call control for MO (Mobile Originated) calls * TCH/F support.

=== Things that are implemented but don't work === * unfinished support for multiple [wiki:TRX] in one [wiki:BTS] * paging group calculation

=== Things that are missing === * Cell Broadcast * processing/switching of calls from one phone to another * demultiplex of the four 16k sub-channels with voice data contained in one [wiki:E1] timeslot * transcoding of voice data * TCH/H voice calls * [wiki:CSD] calls * handover between multiple [wiki:BTS] * emergency call handling * Discontinuous TX and RX ([wiki:DTX] / [wiki:DRX]) support

Authors

OpenBSC was mainly developed by [http://laforge.gnumonks.org/ Harald Welte]. Contributions by Holger Freyther, Stefan Schmidt, Daniel Willmann, Jan Luebbe and Thomas Seiler.

Thanks to Dieter Spaar for his [wiki:BS11-Init], without which we would not have been able to make progress as quickly as we did.