OpenBSC April 2025

openbsc@lists.osmocom.org

9 participants
16 discussions

Splitting out M3UA and MTP3 out of Open BSC into a separate library
by Arran Cudbard-Bell 18 Nov '25

18 Nov '25

Hi, Developing a module for FreeRADIUS to support EAP-SIM and EAP-AKA authentication against a HLR. The HLR we were targeting only supported a SCTP/M3UA/SCCP/TCAP/MAP stack, so we couldn't use SUA. Ripping the M3UA/MTP3 code out of OpenBSC worked surprisingly well. We ended up running the event loop in a separate thread to work around the threading issues. Unfortunately the HLR implements the ANSI variant of everything, whereas OpenBSC and supporting libraries seem to have been written to be compatible with the ITU standards. ...but the differences are fairly minor at MTP3 and SCCP layers, and i've started work on a patchset for libosmo-sccp. https://gerrit.osmocom.org/#/c/73/ Anyway, trying to gauge interest in splitting those layers out of Open BSC into a separate library, would be happy to take on M2UA as well for consistency. It would almost certainly get more projects using the code. There's very little out there even in Perl land for working with SS7. Thanks, -Arran Arran Cudbard-Bell <a.cudbardb(a)freeradius.org> FreeRADIUS Development Team FD31 3077 42EC 7FCD 32FE 5EE2 56CF 27F9 30A8 CAA2

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ip.access nano 3G S8 Configuration
by John Thewlis - Meath Broadband 18 Nov '25

18 Nov '25

We are trying to setup this AP as part of the 3.5G Osmocom project. We have the software stack operational and are now preparing the nano for testing. When we try to login via telnet at port 8090 we are getting a constant refusal to connect:- root@osm/openbsc/openbsc/src/ipaccess# telnet 192.168.192.30 8090 Trying 192.168.192.30... telnet: Unable to connect to remote host: Connection refused The device seems to be locked as indicated by the leds on the front panel. We have tried resetting the nano to see if this would help but to no avail. Any ideas as to how to access the device for initial configuration?. Thanks John

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cmd2 update causing pySim-shell to fail
by bryan coxwell 18 Nov '25

18 Nov '25

Hi all, Just wanted to share an issue and a quick workaround I found for it in case anyone else has the same problem. I believe a cmd2 update is causing pySim-shell to fail. After installing it on a fresh install of Ubuntu Server 20.04 and getting the following error when I run "python3 pySim-shell -p0": >Using PC/SC reader interface >Autodetected card type: sysmoUSIM-SJS1 >AIDs on card: > USIM: a0000000871002ffffffff8907090000 >Traceback (most recent call last): > File "pySim-shell.py", line 512, in <module> > app = PysimApp(card, rs, opts.script) > File "pySim-shell.py", line 59, in __init__ > super().__init__(persistent_history_file='~/.pysim_shell_history', allow_cli_args=False, use_ipython=True, auto_load_commands=False, command_sets=basic_commands, >startup_script=script) >TypeError: __init__() got an unexpected keyword argument 'use_ipython' If you run into this you can fix it by uninstalling cmd2 and reinstalling cmd2 with "pip3 install cmd2==1.5". Best, Bryan

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GPRS - local and foreign TLLIs
by Luca Melette 18 Nov '25

18 Nov '25

Hello everybody, after setting up a nanoBTS with OpenBSC/SGSN/GGSN, I had some troubles trying to connect my smartphone to the GPRS cell. Investigating the BTS-to-SGSN traffic, I saw that the frames sent by the SGSN were all marked with the same N(U) value (at LLC layer), the value was 0. With some debug, I found that the there was a mismatch in the TLLI storage, used to keep the status of attached terminals. The mentioned code is contained in gprs_llc.c, involving LL Entity functions and gprs_llc_tx_ui(). /* look-up or create the LL Entity for this (TLLI, SAPI) tuple */ lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi); if (!lle) { struct gprs_llc_llme *llme; LOGP(DLLC, LOGL_ERROR, "LLC TX: unknown TLLI 0x%08x, " "creating LLME on the fly\n", msgb_tlli(msg)); llme = llme_alloc(msgb_tlli(msg)); lle = &llme->lle[sapi]; } The TX function uses the previously received TLLI to lookup for the LLE. The lle_by_tlli_sapi() performs the search, but preliminary it applies a foreign2local TLLI conversion to ensure to have a local one. Since no valid entry for the searched TLLI is found, a new one is created. And the problem is here. The new entry has the foreign TLLI. Next time the lookup fails again, and a new entry is created. This way, the counter N(U) is always reset, and the mobile do not recognize the message sequence and no attach is possible. My question is about foreign and local TLLIs. I patched the lookup, avoiding the conversion, so that the LLE is found and everything works fine... but... What is the sense of the conversion? Should the TLLI be always stored as a local one? Can this problem be solved with another foreign2local while allocating new entries? Actually, my problem has been solved with that workaround. But I'm curious to know what is the right way. Hope somebody can answer :) Thanks. Cheers, LM

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Need nano3G (S8 - Model 237A)
by Akib Sayyed 18 Nov '25

18 Nov '25

Dear List I am extremely sorry for off the topic question. I am willing to buy nano3G Nodeb. Is anyone in list have spare which can be sold. Please let me know. -- Akib Sayyed Matrix-Shell akibsayyed(a)gmail.com akibsayyed(a)matrixshell.com Mob:- +91-966-514-2243 <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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Pysim error: SW match failed
by Martin Nagy 16 Aug '25

16 Aug '25

Hi all, After buying a super Sim Kit (16 in 1) from China, I tried the reader (green PCB inside a blue transparent plastic case with a blue LED) and SIM (identified as a fakesupersim) with pysim tool. However i am getting the following error: /pySim-prog.py -n 26C3 -c 49 -x 262 -y 42 -z 1234 -j 1 -t auto Insert card now (or CTRL-C to cancel) Autodetected card type fakemagicsim Generated card parameters : > Name : 26C3 > SMSP : e1ffffffffffffffffffffffff058100945555ffffffffffff000000 > ICCID : 8949262427518313026 > MCC/MNC : 262/42 > IMSI : 262422461512085 > Ki : 7b74741a1ee14337ec23f9ab92a13648 > OPC : ccd867d60797d8d45354a51b3ef568ff Programming ... Traceback (most recent call last): File "./pySim-prog.py", line 530, in <module> card.program(cp) File "/home/nadicek/pysim/pysim/pySim/cards.py", line 231, in program self._scc.update_binary('6f30', hplmn + 'ff' * (tl-3)) File "/home/nadicek/pysim/pysim/pySim/commands.py", line 53, in update_binary return self._tp.send_apdu_checksw(pdu) File "/home/nadicek/pysim/pysim/pySim/transport/__init__.py", line 87, in send_apdu_checksw raise RuntimeError("SW match failed ! Expected %s and got %s." % (sw.lower(), rv[1])) RuntimeError: SW match failed ! Expected 9000 and got 9804. I checked mailing lists and haven’t found anybody who had similar problem with pysim. Also I have tried forcing different models of SIM, but nothing is working. Obviously I can remove this check from the script file (__init__.py in /pySim/transport), however somebody had a reason to put such condition there. I would like to ask if it is safe to remove that line of code and the purpose of that line of code. Thanks a lot and best regards Martin

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pycrate repo update
by benoit michau 22 Jul '25

22 Jul '25

Dear osmocom developpers, This is just to let you know that the Python library pycrate has a new home : https://github.com/pycrate-org/pycrate. The packages on Pypi are now feeded from there. This library can be used in many cases dealing with mobile signalling. I wanted to let you know, as even if I am not aware of any osmocom projects depending on it, some of you may use the library from time to time, or could have local applications depending on it. Best Regards Benoit

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Re: Help with sccp library
by mosbah abdelkader 07 Jul '25

07 Jul '25

> I don't understand. This callback will be called with data you need to write > to the network. In case of MTP Level3 you will need to wrap that around the > msgb you got. I means: is the interaction with mtp3 layer implemented (is sending sccp data by mtp3 implemented by the library?)? Also, what about the reception of data from mtp3 layer. is that implemented in the sccp lib. I am asking these questions because I see the code of mtp3 in the lib but no significant call is present in the sccp part of the lib. Thank you for your help.

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Issues with writing adoc manual for contributed library
by Mychaela Falconia 27 Jun '25

27 Jun '25

Hello Osmocom community, Over the past several months I developed my own RTP endpoint implementation library (alternative to libortp), and I seek to get it merged into libosmo-netif so it can be used by OsmoBTS as an option: https://gerrit.osmocom.org/c/libosmo-netif/+/39280 https://gerrit.osmocom.org/c/libosmo-netif/+/39281 https://gerrit.osmocom.org/c/libosmo-netif/+/39291 I am now working on documentation, which I need to finish before I can lift these patches out of WIP in Gerrit. The last of the 3 WIP patches linked above is the one adding an adoc manual, built with the same tools as other Osmocom manuals, and I need some help with this one: 1) When I run './configure --enable-manuals' followed by 'make' on the Debian machine which Vadim provided to me for Osmocom documentation work, everything seems successful and I get a PDF rendering of my WIP manual. However, as soon as I uploaded this patch to Gerrit, I see a build failure in Jenkins. What am I doing wrong? I'm afraid that my knowledge of Autotools is not good enough to figure this one out. 2) My progress in writing the actual manual has reached the point where I need to insert some graphical diagrams showing the flow of RTP packets and the latency and jitter they experience in transit. I am thinking of one horizontal axis showing regularly spaced packets as they are emitted by the source, then forward-and-down arrows showing their transit with fixed or variable latency, then another horizontal axis below showing the receiver's view of time, with marked arrival times of packets (endpoints of latency arrows) and fixed-spacing times when the GSM or TDM system polls the jitter buffer. Question: what is the appropriate tool within the accepted Osmocom adoc suite for drawing such diagrams? If I weren't trying to get my RTP implementation accepted into Osmocom, I would have written this manual in troff on my favorite 1980s UNIX system, using pic preprocessor in the troff suite for graphical drawings like this one - but I reason that I need to write my manual within Osmocom documentation framework in order to maximize the chance of the associated code library being accepted into libosmo-netif, with follow-on patches to osmo-bts to use it optionally as an alternative to libortp. 3) When I do successful test builds on Vadim's Debian machine and get a PDF rendering of my WIP manual, the cover page in the PDF features both Sysmocom and Osmocom logos just like the mainstream Osmocom manuals, with Sysmocom logo on top. While this arrangement is probably appropriate for the existing manuals which were written predominantly by members of Sysmocom crew, it seems quite wrong for an external contributor's manual that does not contain a single sentence written by Sysmocom. How do I tweak things to remove that Sysmocom logo from the cover page, or even better, put San Diego 2G Association logo in its place? My contributions to Osmocom are directly linked to my efforts to build a new GSM network in San Diego, hence there is some symmetry between Sysmocom and SD2G in terms of Osmocom FLOSS project contributions, except for the rather big asymmetry in that SD2G is strictly non-profit. M~

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Possible Bug Issue - BAND_INDICATOR bit value is reversed
by Volkan Akkuş 27 May '25

27 May '25

Dear Sir/Ma'am, I kindly ask you to check on information below for a possible error. The claim is that the return bit value of the following function is reversed. It is supposed to be 1 instead of 0 and 0 instead of 1. https://gitea.osmocom.org/cellular-infrastructure/osmo-bsc/src/commit/2b718… Following sources are presented as proof for the claim. - Image_1 https://www.etsi.org/deliver/etsi_ts/145000_145099/145014/06.02.00_60/ts_14… - Image_2 https://www.etsi.org/deliver/etsi_ts/145000_145099/145014/06.02.00_60/ts_14… - Image_3 https://data.epo.org/publication-server/rest/v1.2/publication-dates/2016062… Thank you for your time and effort. Sorry if I have wasted your time. Volkan from Turkiye

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OpenBSC April 2025