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Harald Welte c2007855ce Implement checks for duplicate uplink UL L3 message
According to TS 24.007 Section 11.2.3.2.3, it is possible that uplink L3
messages are duplicated in some scenarios, particularly during
assignment/handover procedure.

To avoid L3 entities from seeing duplicated messages, there's a modulo-2
or modulo-4 message sequence counter, based on which the MSC can detect
and suppress such duplicate messages.

It appears that even our unit tests were wrong in that regard so far.
Rather than manually adjusting each and every message, let's make sure
that the sequence number generation always increments as expected, and
that during matching of incoming messages, sequence numbers are masked
out.

Note: the tests will only pass from libosmocore Change-Id
Iec875a77f5458322dfbef174f5abfc0e8c09d464 onwards, due to
gsm48_hdr_msg_type() being broken in earlier versions.

Change-Id: Id15e399ab7e1b05dcd426b292886fa19d36082b1
Closes: #2908
2018-02-03 20:30:03 +00:00
contrib jenkins.sh: Don't depend on osmo-ggsn 2018-01-25 00:18:05 +01:00
debian Migrate from OpenSSL to osmo_get_rand_id() 2017-12-27 11:11:14 +00:00
doc examples: apply mgcp_client vty rename from 'mgcpgw' to 'mgw' 2017-11-08 03:24:13 +00:00
include Implement checks for duplicate uplink UL L3 message 2018-02-03 20:30:03 +00:00
m4 move openbsc/* to repos root 2017-07-12 23:17:10 +00:00
src Implement checks for duplicate uplink UL L3 message 2018-02-03 20:30:03 +00:00
tests Implement checks for duplicate uplink UL L3 message 2018-02-03 20:30:03 +00:00
.gitignore Remove traces of meas_feed 2018-01-24 14:04:46 +00:00
.gitreview update .gitreview to new repo url 2017-08-08 17:26:28 +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 2017-07-12 23:17:10 +00:00
COPYING move openbsc/* to repos root 2017-07-12 23:17:10 +00:00
Makefile.am Remove unneeded .py scripts 2017-12-03 21:14:10 +00:00
README rewrite README 2017-09-06 16:33:41 +02:00
README.vty-tests Remove obsolete ./configure option 2017-11-29 14:24:54 +00:00
configure.ac Migrate from OpenSSL to osmo_get_rand_id() 2017-12-27 11:11:14 +00:00
git-version-gen git-version-gen: look for .git in ./, not ../ 2017-07-12 23:28:38 +00:00
osmoappdesc.py doc/examples: add detailed cs7 config examples 2017-09-07 03:10:36 +02:00

README

About OsmoMSC
=============

OsmoMSC 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.

OsmoMSC was one of the parts split off from the old openbsc.git. Before, it was
the libmsc part of the old OsmoNITB. Since a true A interface and IuCS for 3G
support is available, OsmoMSC exists only as a separate standalone entity.

OsmoMSC exposes
- GSUP towards OsmoHLR (or a MAP proxy);
- A over IP towards a BSC (e.g. OsmoBSC);
- IuCS towards an RNC or HNB-GW (e.g. OsmoHNBGW) for 3G voice;
- MNCC (Mobile Network Call Control derived from GSM TS 04.07);
- SMPP 3.4 (Short Message Peer-to-Peer);
- The Osmocom typical telnet VTY and CTRL interfaces.

Find OsmoMSC issue tracker and wiki online at
https://osmocom.org/projects/osmomsc
https://osmocom.org/projects/osmomsc/wiki