Osmocom's Base Station Controller for 2G mobile networks https://osmocom.org/projects/osmobsc
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Philipp Maier a1ff30920d pcu_sock: fix PCUIF interface (PCH)
The PCUIF interface implementation in osmo-bsc provides two ways to
access the paging channel (PCH).

1) Under the SAPI PCU_IF_SAPI_PCH PAGING COMMAND messages are accepted
as whole MAC block but the format is in the style that we are going
to deprecate with PCUIF v.11. Also at the moment those PAGING COMMANDs
are not confirmed towards the PCU. This is also not necessary since
osmo-pcu would silently drop such confirmations. (see pcu_rx_data_cnf
in pcu_l1_if.cpp)

2) Under the SAPI PCU_IF_SAPI_PCH_DT messages are also accepded as
MAC blocks but the SAPI will only accept IMMEDIATE ASSIGNMENT messages.
The messages are encapsulated in a struct that holds IMSI (paging group)
and TLLI (used for confirmation) as separate struct members. The
messages are also confirmed towards the PCU as it should be.

Since we want to depreacete the older V.10 version of PCUIF and there is
not much benefit in maintaining two interfaces we should use
SAPI PCU_IF_SAPI_PCH_DT for both message types. This also requires small
adjustments to osmo-pcu (see Depends).

Depends: osmo-pcu.git I99cfe373fa157cfb32b74c113ad9935347653a71
Related: OS#5927
Change-Id: I82443f2b402aa2416469c8c50b1c050323ef3b8f
2023-05-24 12:29:00 +02:00
contrib contrib/jenkins: create workspace.tar.xz on error 2023-05-23 16:18:11 +02:00
debian debian: set compat level to 10 2023-04-27 12:28:23 +00:00
doc cosmetic: Clarify language ip.access nanoBTS vs. all IPA Abis/IP 2023-05-08 06:28:52 +02:00
include pcu_sock: fix PCUIF interface (PCH) 2023-05-24 12:29:00 +02:00
m4 Drop unneeded ax_check_compile_flag.m4 2022-01-11 18:15:20 +01:00
src pcu_sock: fix PCUIF interface (PCH) 2023-05-24 12:29:00 +02:00
tests test case fixup: Add missing (void) empty argument list specification 2023-05-08 06:31:11 +02:00
.gitignore .gitignore: remove non-existing files 2022-07-22 03:35:22 +07:00
.gitreview .gitreview: update repo url to new location 2017-08-08 17:24:04 +02:00
.mailmap add .mailmap file for mapping git author name/mail in shortlog 2016-08-08 17:40:28 +00:00
AUTHORS move openbsc/* to repos root 2017-08-27 03:52:43 +02:00
COPYING move openbsc/* to repos root 2017-08-27 03:52:43 +02:00
Makefile.am manuals: generate vty reference xml at build time 2020-06-16 10:16:30 +00:00
README.md convert README to README.md; expand on all fronts 2022-06-18 13:34:46 +02:00
README.vty-tests update git URLs (git -> https; gitea) 2022-06-18 14:04:11 +02:00
TODO-RELEASE bsc_mgw_setup: use mgcp_client_pool_empty() 2023-04-04 16:32:27 +02:00
configure.ac Bump version: → 1.10.0 2023-02-07 17:21:11 +01:00
git-version-gen git-version-gen: Don't check for .git directory 2018-07-24 18:04:51 +02:00
osmoappdesc.py osmoappdesc.py: add more config files for testing 2023-03-31 10:46:04 +00:00


osmo-bsc - Osmocom BSC Implementation

This repository contains a C-language implementation of a GSM Base Station Controller (BSC). IT is part of the Osmocom Open Source Mobile Communications project.

OsmoBSC exposes

  • A over IP towards an MSC (e.g. OsmoMSC): 3GPP AoIP or SCCPlite
  • Abis interfaces towards various kinds of BTS (osmo-bts, sysmobts, nanoBTS, Siemens, Nokia, Ericsson)
  • The Osmocom typical telnet VTY and CTRL interfaces.
  • The Osmocom typical statsd exporter.
  • Cell Broadcast Service Protocol (CBSP) towards a CBC (Cell Broadcast Centre, such as osmo-cbc).
  • Lb interface towards a SMLC (Serving Mobile Location Centre, such as osmo-smlc).


You can find the OsmoBSC issue tracker and wiki online at https://osmocom.org/projects/osmobsc and https://osmocom.org/projects/osmobsc/wiki.

GIT Repository

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

    git clone https://gitea.osmocom.org/cellular-infrastructure/osmo-bsc

There is a web interface at https://gitea.osmocom.org/cellular-infrastructure/osmo-bsc


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

There also is an Abis reference Manual describing the OsmoBTS specific A-bis dialect, as well as a CBSP Reference Maunal describing the level of CBSP conformance.

Mailing List

Discussions related to osmo-bsc are happening on the openbsc@lists.osmocom.org mailing list, please see https://lists.osmocom.org/mailman/listinfo/openbsc for subscription options and the list archive.

Please observe the Osmocom Mailing List Rules when posting.


Our coding standards are described at https://osmocom.org/projects/cellular-infrastructure/wiki/Coding_standards

We us a gerrit based patch submission/review process for managing contributions. Please see https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit for more details

The current patch queue for osmo-bsc can be seen at https://gerrit.osmocom.org/#/q/project:osmo-bsc+status:open


OsmoBSC originated from the OpenBSC project, which started as a minimalistic all-in-one implementation of the GSM Network. In 2017, OpenBSC had reached maturity and diversity (including M3UA SIGTRAN and 3G support in the form of IuCS and IuPS interfaces) that naturally lead to a separation of the all-in-one approach to fully independent separate programs as in typical GSM networks.

OsmoBSC was one of the parts split off from the old openbsc.git. Before, it worked as a standalone osmo-bsc binary as well as a combination of libbsc and libmsc, i.e. the old OsmoNITB. Since the standalone OsmoMSC with a true A interface (and IuCS for 3G support) is available, OsmoBSC exists only as a separate standalone entity.

OsmoBSC-NAT is a specialized solution to navigating RTP streams through a NAT. (Todo: describe in more detail)