OpenBSC December 2016

openbsc@lists.osmocom.org

20 participants
41 discussions

GPRS - local and foreign TLLIs
by Luca Melette 04 Feb '26

04 Feb '26

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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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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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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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 08 Jul '25

08 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.

4 3

dynamic traffic channels
by Neels Hofmeyr 20 May '25

20 May '25

On Tue, Jun 28, 2016 at 10:05:28AM +0200, Harald Welte wrote: > [translated from german] > is it certain that we switch a channel to PDCH only when > gprs mode != none? A TS can be GSM_PCHAN_TCH_F_PDCH; those are the only ones for which we send a PDCH ACT message. We send a PDCH ACT message - during init (CHANNEL OML's state changed to enabled -> send PDCH ACT), - and upon channel release ack when pchan == GSM_PCHAN_TCH_F_PDCH. So the question is, when we receive a channel release ack, could that be the PDCH release and we switch PDCH right back on by accident? No, because we only receive a chan rel ack when the *TCH/F* is being released. That is because the PDCH release is initiated "internally" from the PDCH DEACT, and thus this condition in common/rsl.c rsl_tx_rf_rel_ack() catches on, which existed before dyn PDCH: if (lchan->rel_act_kind != LCHAN_REL_ACT_RSL) { LOGP(DRSL, LOGL_NOTICE, "%s not sending REL ACK\n", gsm_lchan_name(lchan)); return 0; } In rsl_rx_rf_chan_rel() the rel_act_kind is set to LCHAN_REL_ACT_RSL, but not in the rsl_rx_dyn_pdch(). This is analogous to the ip.access way -- the ip.access nanobts replies to a PDCH DEACT with a PDCH DEACT ACK and doesn't send a separate channel release ack. Maybe we could set rel_act_kind to some new LCHAN_REL_ACT_IPAC_DYN_PDCH for clarity? (But we shouldn't actually send a release ack, to stay compatible.) Even though it works as-is, we should indeed add another flag check: - We do check the flags that no ACT/DEACT is already pending; - And we do send a PDCH DEACT only if ts->flags & TS_F_PDCH_ACTIVE; - But we would send a PDCH ACT despite ts->flags & TS_F_PDCH_ACTIVE. This should never happen, but it would make sense to ensure that. ~Neels

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osmo-trx jenkins
by Max 19 Jan '17

19 Jan '17

HI. A little heads up: uhd version in jenkins building osmo-trx should be updated to 3.9.0 - this would allow gerrit #1117 to be properly verified by jenkins. -- Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Director: Harald Welte

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RFC: OsmoDevCon 2017 planning
by Harald Welte 10 Jan '17

10 Jan '17

Dear Osmocom Community, [please respect the Reply-To and post all follow-up discussion to this to openbsc(a)lists.osmocom.org, so we avoid having long threads cross-posted to several mailing lists.] >From 2012 to 2016 we were running a series of small, invitation-only Osmocom Developer Conferences. Access was intentionally restricted to those community members who have demonstrated an existing track record of contribution to any of the projects under the Osmocom umbrella. This format of a small, tightly knit group of about 20 people has been successful over the years, and I have received a lot of positive feedback from past participants. On the other hand, the Osmocom project has grown in scope and diversity, and some of those projects don't have all that much relationship to each other - except being started by people from within the same group. There's the cellular communications (GSM/GPRS/EDGE/UMTS and hopefully at some point LTE) protocols which is attracting a lot of professional users. And then there's pure community projects like rtl-sdr, OsmocomBB, OsmocomGMR and many other efforts. Particularly the cellular infrastructure projects (OsmoBTS, OsmoPCU, OsmoBTS, OsmoNITB, OsmoSGSN, OpenGGSN, OsmoIuh & co) are somehow "standing out" of the othe projects in the context of having a wider user bsae, and in that user base also primarily commercial users. So I'd like to start a discussion on how to possibly change the event format to accomodate the various interests and parties. I definitely don't want to loose the "annual meeting of old friends" atmosphere, while at the same time also opening up to other interested parties. One idea would be to keep OsmoDevCon as-is and have a separate event where non-contributing/developing users / sysadmins / system integrators could also be attending. Another idea would be to split into a 'user day' and 'developer days' format. This is something the netfilter developer workshops have been using for many years, and from my limited insight quite successfully so. The "user day" is more like a traditional tech conference, with a large auditorium and talks oriented towards users / sysadmins / integrators of the software. The "developer days" are the invitation-only part, for known contributing developers only, similar to what we have at OsmoDevCon. Having both events (or both parts of an event) back-to-back has the advantage that a large number of potential speakers for the 'user day' are already present, and they don't have to travel yet another time. One could even structure it further and say we have one user day, one public 'Osmocom cellular developer day' and then the closed 'OsmoDevCon classic', maybe reduced from 4 days to 3 or even 2 days only? What is the general opinion about this? Are there people lurking on this list who would be interested in attending a public 'user day' or even 'developer day' about the Osmocom cellular projects, with presentations and workshops around topics such as running Osmocom based cellular networks? In terms of when/where, I would suggest to keep the tradition of April in Berlin/Germany. But I'm of course very happy if somebody wants to host it some place else... Regards, and looking forward to meeting you [again] in 2017, 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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Re: libosmocore[master]: libosmocoding: migrate transcoding routines from OsmoBTS
by Neels Hofmeyr 01 Jan '17

01 Jan '17

On Sat, Dec 31, 2016 at 01:10:30PM +0000, Vadim Yanitskiy wrote: > Regarding to the change, there is a problem: despite all tests > pass without any problems on my machine, some tests fail on Jenkins. > I will try to find out, what's wrong. Let me know if I should install some library dependencies or similar on the build slaves... ~N -- - Neels Hofmeyr <nhofmeyr(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschäftsführer / Managing Directors: Harald Welte

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[XTRX] Price?
by Choukou Moun 26 Dec '16

26 Dec '16

Hello. Wath is the price of the xtrx board ? Thank you.

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OpenBSC December 2016