MNCC<->SIP bridge; attaches to OsmoMSC to interface with external SIP VoIP telephony
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Maxim Suraev 8120b11eaa Set working directory in systemd service file 5 months ago
contrib Set working directory in systemd service file 5 months ago
debian Bump version: → 1.6.1 7 months ago
doc debian: create -doc subpackage with pdf manuals 4 years ago
src mncc: rework passing GCR over the MNCC interface 1 year ago
tests distcheck/tests: Add the referenced for testing 7 years ago
.gitignore .gitignore: Get rid of new autofoo tmp files 2 years ago
.gitreview Add git review config 6 years ago
COPYING Initial commit for a MNCC to SIP gateway (and maybe auth GW too) 7 years ago EXTRA_DIST: debian, contrib/* 3 years ago Convert + Expand README file 7 months ago
TODO-RELEASE Add TODO-RELEASE 1 year ago Bump version: → 1.5.0 2 years ago
git-version-gen Fix git-version-gen 5 years ago switch to python 3 3 years ago

osmo-sip-connector - Osmocom SIP connector

This implements an interface between the MNCC (Mobile Network Call Control) interface of OsmoMSC (and also previously OsmoNITB) and SIP.

Call identities can be either the MSISDN or the IMSI of the subscriber.

Requirements of Equipment

  • DTMF need to be sent using SIP INFO messages. DTMF in RTP is not supported.
  • BTS+PBX and SIP connector+PBX must be in the same network (UDP must be able to flow directly between these elements)
  • No handover support.
  • IP based BTS (e.g. Sysmocom sysmoBTS but no Siemens BS11)
  • No emergency calls


  • PT of RTP needs to match the one used by the BTS. E.g. AMR needs to use the same PT as the BTS. This is because rtp_payload2 is not yet supported by the osmo-bts software.

  • AMR SDP file doesn't include the mode-set params and allowed codec modes. This needs to be configured in some way.


You can find the osmo-sip-connector issue tracker and wiki online at and

GIT Repository

You can clone from the official osmo-msc.git repository using

    git clone

There is a web interface at


User Manuals and VTY reference manuals are [optionally] built in PDF form as part of the build process.

Pre-rendered PDF version of the current "master" can be found at User Manual as well as the VTY Reference Manual

Mailing List

Discussions related to osmo-sip-connector are happening on the mailing list, please see for subscription options and the list archive.

Please observe the Osmocom Mailing List Rules when posting.


Our coding standards are described at

We us a gerrit based patch submission/review process for managing contributions. Please see for more details

The current patch queue for osmo-sip-connector can be seen at