OpenBSC April 2020

openbsc@lists.osmocom.org

17 participants
29 discussions

OsmoNITB timeslots configuration and UmTRX
by Родион Гадыршин 27 Jan '26

27 Jan '26

Hello, list. I have umtrx v2.1 and I have already built GSM and GPRS components. Now I want to know which way of configuring timeslots in osmobsc.cfn is the best. I want GPRS, calls and SMS work. My current configuration is: timeslot 0 phys_chan_config CCCH+SDCCH4 hopping enabled 0 timeslot 1 phys_chan_config SDCCH8 hopping enabled 0 timeslot 2 phys_chan_config TCH/F hopping enabled 0 timeslot 3 phys_chan_config TCH/F hopping enabled 0 timeslot 4 phys_chan_config PDCH hopping enabled 0 timeslot 5 phys_chan_config PDCH hopping enabled 0 timeslot 6 phys_chan_config PDCH hopping enabled 0 timeslot 7 phys_chan_config PDCH hopping enabled 0 Is there a better way to configure? Maybe better use TCH/F_TCH/H_PDCH, but I have heard, that TCH/F is currently not working in dynamic configurations - only TCH/H does. And there is no only TCH/H_PDCH mode. So, could you please give me an advice?

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On the use of 'decmatch' in TTCN-3
by Harald Welte 27 Jan '26

27 Jan '26

Hi, I know that TTCN-3 is still new to a lot of you, but we are writing tons of integration testing against the various osmocom programs in it. It is quite amazing technology, and I would like to ask you to bear with me reading this mail :) Pau was stating the question earlier today on not finding an example on how to use decmatch. Indeed, it took me some months to find that gem in the TTCN-3 world. It solves the problem that you often have during test of layered protocol stacks: you have separate encoders/decoders for each protocol layer, and now you want to match on some of the *inner* payload. So normally, you have some kind of header definition + a binary (octetstring) payload. This happens in RSL with the L3_INFO IE, and just the same on BSSAP/DTAP where again the L3 message (for example call control) is encapsulated inside one information element. Now you have multiple options of addressing the problem: a) hand-written calls to the decoder function b) write na 'emulation' for the entire protocol layer c) use decmatch. a) would look like this (pseudo-code): var octetstring l3oct; var RSL_Message rsl RSL.receive(tr_RSL_DATA_REQ(g_chan_nr, ?, ?)) -> value rsl { var PDU_ML3_MS_NW l3 := dec_PDU_ML3_MS_NW(rsl.payload); if (match(l3, some_template)) { ... do something } ... } Which uses the built-in pattern-matching on the RSL port to match any message that matches the tr_RSL_DATA_REQ template, and stores the resulting RSL message in a variable. It then uses an explicit call to the decoder function of the L3 message, and then uses regular conditional expressions for further matching on that inner L3 payload. This is more or less how you would write in C, python or any other quite imperative programming languages. It's very verbose, time consuming and un-abstract/elegant. TTCN-3 has many declarative aspects to it. Code like the above is a waste of your time :) b) would mean that you implement some test component that handles the RSL messages on its bottom side test port, and the L3 messages on its top side test port. That is a possible way, and if you need a lot of state/logic of RSL, it maeks sense. But what if you really simply want to have a match? Then it would be a lot of effort and a large detour. c) decmatch to the rescue! You can write RSL.receive(tr_RSL_DATA_REQ(g_chan_nr, ?, decmatch tr_RRM_RR_STATUS)) which means: * do a receive on the RSL test port, and match on an incoming RSL message that matches the tr_RSL_DATA_REQ template, with channel number specified, link_id any (?), *and* if the octetstring payload, if decoded, matches the template tr_RRM_RR_STATUS ! This is *extremely* powerful and expressive. It allows you to condense complex, parametric template matching over multiple proocol layers. It would in the end match RSL DATA REQUEST, only if they contained a [valid] encoded RR STATUS. See https://gerrit.osmocom.org/6229 for the actual test case I used for the above examples. Please also note that I never had to even write the function name of the decoder (dec_PDU_ML3_MS_NW), but TTCN-3 *automatically* figures out which decoder function it must call in order to decode from the binary octetstring. Happy (TTCN-3) hacking + Osmocom bugfixing, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

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Need nano3G (S8 - Model 237A)
by Akib Sayyed 18 Jan '26

18 Jan '26

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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osmo-gsm-manuals in project repos: I see no .pdf
by Neels Hofmeyr 08 Jan '26

08 Jan '26

Hi Oliver, so I merged the stuff to add the manuals to the individual git repositories, since you said that it works. But when I do --enable-manuals I don't see any PDF files generated. Also a manual 'make pdf' says "nothing to be done". (I probably should have tried it before merging after all) So what am I doing wrong? Alternatively, can you fix it please? ~N

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Video Recordings of OsmoCon 2017
by Harald Welte 22 Dec '25

22 Dec '25

Hi all, the Osmocom Conference 2017 last week was an overwhelming success. We received lots of positive feedback from all sides. Thanks to all the speakers, to the attendees as well as to the anonymous sponsor of the travel grant funds. It is my great pleasure that due to the great support by C3VOC (The CCC Video Operation Center), we have full recordings of all talks given at OsmoCon 2017. You can find the videos on the C3VOC site at https://media.ccc.de/search/?q=osmocon They are also linked individually from the OsmoCon 2017 homepage at https://osmocom.org/projects/osmo-dev-con/wiki/OsmoCon2017 I hope the video recordings will be of help for everyone who could not make it to the event in person. We will also be collecting the slides and put them up on the wiki during the next few days. Please don't hesitate to raise any feedback and/or questions. Technical feedback/questions regarding Osmocom software / projects should be addressed to the appropriate mailing lists, such as openbsc(a)lists.osmocom.org. Feedback to the organizers should be sent to osmocon2017(a)sysmocom.de. Looking forward to the next OsmoCon, which we'll expect to be spanning ore than just a single day. Regards, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

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Splitting out M3UA and MTP3 out of Open BSC into a separate library
by Arran Cudbard-Bell 15 Dec '25

15 Dec '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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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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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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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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OpenBSC April 2020