OpenBSC March 2021

openbsc@lists.osmocom.org

11 participants
20 discussions

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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Problem while running NIB on Open Cellular Base sation
by Brackley Casinga 31 Jan '24

31 Jan '24

Hi, My name is Brackley Cassinga Form DRC, we run a community network called pamoja net where we offer gsm services using osmocom open source software and OC Base station. Recently I have tried to install another base station as the same installed but I could not find any resource guiding through all the steps to take to run NIB on a base station. I'm currently running Ubuntu and I will appreciate if you could guide me on the installation of BSC,hlr,MSC , in order to run a basic gsm network. Thank you. Regards -- *Ir Brackley heshima Casinga **Pacifique* *CEO and Founder of kwanzatechnologie* KwanzaTechnologies ,GlobalElectronics +243977265291 | +243977265291 | Pcassinga(a)gmail.com/ brackley(a)ensemblepourladifference.org www.kwantechnologies.jimdosite.com <http://www.kwantechnologies.com/> | Skype: Brackley cassinga <https://webapp.wisestamp.com/#> Av Semliki N 43

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WIP / RFC for pysim 'next generation;' aka pysim-shell
by Harald Welte 07 Apr '21

07 Apr '21

Dear Osmocom community, pySim-prog was nice when there were only 5 parameters on a SIM that we could program, and where the use case was pretty limited. Today, we have SIM/USIM/ISIM cards with hundreds of files and even more parameters to program. We cannot add a command line argument for each file to pySim-prog. Instead, this introduces an interactive command-line shell / REPL, in which one can navigate the file system of the card, read and update files both in raw format and in decoded/parsed format. The idea is primarily inspired by Henryk Ploetz' venerable cyberflex-shell, but implemented on a more modern basis using the cmd2 python module. You can see the very first prototype in the laforge/shell branch of pysim.git You can do things with it like this: ===> Start-up and authenticate with adm pin ---------------------------------------------------------------------- $ ./pysim-shell.py -p 0 Using PC/SC reader interface Autodetected card type: sysmoISIM-SJA2 AIDs on card: ['a0000000871002ffffffff8907090000', 'a0000000871004ffffffff8907090000'] Welcome to pySim-shell! pySIM-shell (3f00)> verify_adm 92990895 ---------------------------------------------------------------------- ===> interactive help ---------------------------------------------------------------------- pySIM-shell (3f00)> help Documented commands (use 'help -v' for verbose/'help <topic>' for details): ISO7816 Commands ================ read_binary select_adf select_file update_binary update_record verify_chv pySim Commands ============== intro verify_adm USIM Commands ============= read_ehplmn ust_service_activate ust_service_deactivate pySim-shell built-in commands ============================= alias help macro quit run_script shell edit history py run_pyscript set shortcuts ---------------------------------------------------------------------- ===> more interactive help ---------------------------------------------------------------------- pySIM-shell (3f00)> help read_binary usage: read_binary [-h] [--file-id FILE_ID] [--offset OFFSET] [--length LENGTH] [--record-nr RECORD_NR] Read binary data from a transparent EF optional arguments: -h, --help show this help message and exit --file-id FILE_ID File ID --offset OFFSET Byte offset for start of read --length LENGTH Number of bytes to read --record-nr RECORD_NR Number of record to read ---------------------------------------------------------------------- ===> navigating the FS and reading files ---------------------------------------------------------------------- pySIM-shell (3f00)> select_file 7f20 ['622c8202782183027f20a509800171830400018d088a01058b032f0601c60f90017083010183018183010a83010b'] pySIM-shell (3f00/7f20)> read_binary --file-id 6f07 089910070000400310 ---------------------------------------------------------------------- ===> interaction with local filesystem, i.e. I/O redirect + shell commands ---------------------------------------------------------------------- pySIM-shell (3f00)> select_adf a0000000871002 pySIM-shell (a0000000871002)> select_file 5f3b pySIM-shell (a0000000871002/5f3b)> read_binary --file-id 4f20 > /tmp/f pySIM-shell (a0000000871002/5f3b)> !cat /tmp/f ffffffffffffffff07 ---------------------------------------------------------------------- ===> piping output through shell tools like grep ---------------------------------------------------------------------- pySIM-shell (3f00)> read_ust | grep 86 Service 86 - Allowed CSG Lists and corresponding indications ---------------------------------------------------------------------- ===> enabling/disabling services ---------------------------------------------------------------------- pySIM-shell (3f00/7f20)> ust_service_activate 123 pySIM-shell (3f00/7f20)> ust_service_deactivate 123 ---------------------------------------------------------------------- It's a very first prototype, but it is really promising. The major tasks I see to make this go anywhere is: * have "File" class with encoder/decoder methods, which are registered automatically with a 'file system' layer that knows about the DF/ADF hierarchy ** this allows us to have a "read-decoded" command, which will call the decode method of the file, automatically resolved by the selected FID/path * automatic mapping of file-name -> FID and FID -> file name ** when printing (like in the path), use the human-readable names ** allow users to use human-readable names in SELECT * decode + display the TLVs / FCPs after a SELECT (like cyberflex-shell * ability to enable/disable APDU trace * dynamically register/deregster commands based on the path, i.e. offer USIM commands only when in ADF_USIM We have quite a bit of that infrastructure in the c-language libosmosim, (part of libosmocore.git), but unfortunately not in python :/ Let me know if anyone is interested in joining this effort. 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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Question about establishing stable internet link between UE and HNB connected to our developed network core.
by morteza ali Ahmadi 26 Mar '21

26 Mar '21

Hi, osmocom team members. In order to have an internet connection in UE, we have run OsmoGGSN project to set up GGSN. Also, SGSN is developed in our system. At this step, UE connects to our network core and we can query to an arbitrary site in the UE browser and we see the answer of the query without any problem and everything is OK. But after about 30 or 40 seconds, UE sends "Deactivate PDP Context Request" with SM Cause "SM Cause: Protocol error, unspecified (111)" and the connection is reset and a new "Activate PDP Context Request" is required. What is the reason and how can we solve it? -- *When there is much light, The shadow is deep...*

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Idea for 2021: Regular "OsmoDevCall"
by Harald Welte 25 Mar '21

25 Mar '21

Dear Osmocom community, as the pandemic continues and physical meetings are out of the question for the forseeable future, it would be a good idea to have a periodic virtual online meeting of the interested Osmocom community. I was thinking of a format where we would serve two major purposes: 1) technical talks about osmocom relevant topics - ideally current/recent developments * can be pre-recorded to avoid any problems with technical setup, streaming, ... * should ideally have a Q+A session at their initial "airing" during one OsmoDevCall 2) unstructured solicited social event (USSE) * random chat in audio (optionally video) * not recorded, obviously The recording of the technical presentation should then be permanently made available (like the presentations of our prior OsmoCon / OsmoDevCon). Not every OsmoDevCall would neccessarily need the two parts, but I think it would be great if we can make that happen. We could also have e.g. a two-weekly schedule for the USSE and a monthly schedule for the technical presentation. We'd need somebody to volunteer to "manage" the "broadcast" side of this, preferably somebody with at least some prior exposure to online events (like the c3voc). I'm using https://osmocom.org/issues/4928 to collect a tentative list of topics. Feel free to add your ideas there, as well as any comment/ feedback you may have. Regards, Harald -- - Harald Welte <laforge(a)osmocom.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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where to send pySim patches
by Riemer, Björn 18 Mar '21

18 Mar '21

Hello list, we are working on extensions to pySim for the sjs2 card mainly to make our 5G phones to accept our network. How should we send this patches? Via this mailing list or should we wait a little longer until Harald finished restructuring the mailing lists? Best Regards Bjoern

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sysmoISIM-SJA2 clock stop discrepancy
by Mychaela Falconia 10 Mar '21

10 Mar '21

Hello esteemed masters of Osmocom and Sysmocom, As I am doing some experiments with sysmoISIM-SJA2 cards in order to make a contingency plan in case I am not able to buy cards from Grcard beyond the 5 sample cards I got in February (my contact person there hasn't been responding to email for the past 3 days), I have noticed a discrepancy between this card's ATR and the file characteristics byte it returns in response to SELECT in the GSM 11.11 SIM protocol, regarding allowed levels for clock stop. My sysmoISIM-SJA2 cards (bought from the webshop in late Jan into early Feb) return the following ATR: 3B 9F 96 80 1F 87 80 31 E0 73 FE 21 1B 67 4A 4C 75 30 34 05 4B A9 The TA byte for T=15 indicates allowed voltage classes and allowed levels for clock stop. On this card this byte equals 0x87, meaning all 3 voltage classes (good), but also indicating that when the clock is stopped, it should be HIGH. However, the file characteristics byte returned in response to SELECT (both MF and DF_GSM) in the GSM 11.11 SIM protocol is 0xB1; decoding this byte per 3GPP TS 51.011, it says "clock stop allowed, no preferred level". Thus the file characteristics byte says that there is no preferred level, yet ATR says that HIGH level is preferred - or not just preferred, but required? (7816-3 seems to say it is only a preference, not a requirement; I seem to recall some other spec that said it's a requirement, but I can't find it now.) This discrepancy poses a potential problem if these cards are to be used in classic GSM/2G dumbphones whose original firmwares are based on the reference from TI. That reference fw code does not look at ATR for the purpose of determining allowed clock stop levels (most classic SIMs didn't have that T=15 TA byte in their ATR, it became commonly present when UICC/USIM stuff came along), instead it looks at the file characteristics byte returned in response to SELECT of DF_GSM. Furthermore, if the file characteristics byte says that there is no preferred level for clock stop, TI's reference fw configures the hw to leave the clock LOW during idle. I can only reason that other classic dumbphone firmwares (from other chip vendors) may very likely do the same: GSM SIM specs (11.11 and 51.011) don't require ME implementations to look at T=15 bytes in ATR, instead they direct MEs to follow the file characteristics byte. Can someone from Sysmocom officially confirm whether or not it is OK to operate sysmoISIM-SJA2 cards with clock stop at LOW level, contrary to ATR asking it to be HIGH? I have done a limited test of putting one of these cards into an FCDEV3B (with this aspect of the firmware left unmodified, so the clock line was low during idle) and the SIM interface appeared to still be alive after some deep sleep (clock stop) cycles. However, it was a very limited test, and I don't have my own network set up yet to make a more thorough test - and in any case, an official confirmation would be much better than anecdotal observations. TIA, Mychaela

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Osmocom Mailing List re-organization
by Harald Welte 09 Mar '21

09 Mar '21

Dear Osmocom community, This topic has been past due for way too many years by now: A re-organization of our major mailing lists. I would like to propose the following changes. Pleas let me know if you have any comments or feedback. I'm aware that renaming will mean people have to update their mail filter rules, but I think we're long past the point where the names of some of our lists started to confuse users. == openbsc(a)lists.osmocom.org == * openbsc doesn't exist anymore since OsmoNITB, which is also obsolete * does already cover anything "Osmocom CNI" related * Proposed new name: osmocom-cni(a)lists.osmocom.org == osmocom-net-gprs(a)lists.osmocom.org == This date back to when GPRS was a highly experimental add-on to our GSM code base. This list should simply be merged with openbsc@ as osmocom-cni(a)lists.osmocom.org == simtrace(a)lists.osmocom.org == Historically was created to cover only the simtrace project. We should rename this to osmocom-simcard(a)lists.osmocom.org or something along those lines. I would like to suggest it covers * SIMtrace / SIMtrace2 hardware + firmware * pySim and related tools for working with SIM/USIM/UICC cards * any other information / discussion related to SIM/USIM/UICC cards, like OTA, ARA-M, ... == osmodevcon(a)lists.osmocom.org == This has been a private list for people attending OsmoDevCon I would like to open up list membership to the general public, and ensure it also covers the new OsmoDevCall. We could then have discussions regarding feedback, topics, scheduling, etc. on that list. Maybe rename it to osmocom-events(a)lists.osmocom.org instead? To differentiate: osmocom-event-orga(a)lists.osmocom.org should remain a private list related to organizational / administrative topics of those involved with organizing future events. == nextepc(a)lists.osmocom.org == Should have been renamed to open5gs(a)lists.osmocom.org quite some time ago, I simply forgot about it. My apologies. -- - Harald Welte <laforge(a)osmocom.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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Bringing back GrcardSIM2
by Mychaela Falconia 08 Mar '21

08 Mar '21

Hello esteemed masters of Osmocom, (asking here because Harald's proposed osmocom-simcard list hasn't been created yet) I have some questions and experience-based corrections related to the gold nuggets contained in this wiki page: https://osmocom.org/projects/cellular-infrastructure/wiki/GrcardSIM2 First let me establish relevance: even though Sysmocom stopped selling these GR2 cards ages ago and it looks like the wider Osmocom community also stopped playing with them once sysmoUSIM-SJS1 came out, these same GrcardSIM2 cards are still available from Grcard in the present day. A week and a half ago I received 5 sample cards (plain white, no printing, unprogrammed) from Grcard that return the same ATR as is listed for sysmoSIM-GR2, and all of the card-model-specific proprietary commands described on the above wiki page work exactly the same on these cards as they once worked on sysmoSIM-GR2. I am now in the process of ordering a batch of 200 of these cards from Grcard, with my own custom printing applied (so they will look pretty, not plain white and not black like sysmoISIM-SJA2) - essentially I am bringing back an exact equivalent of the discontinued sysmoSIM-GR2. With relevance thus established, let's move on technical questions: * The wiki page describes a file named EF.WEKI, file ID 0001 under DF.GSM. Whoever wrote this wiki page, how did you get this fancy name EF.WEKI? Was there some kind of document from Grcard that described this card-model-specific proprietary file? Does that document still exist somewhere? Can there be some way for mere mortals like me to see that document? * The wiki page describes byte 3 of EF.WEKI as selecting COMP128 algorithm version. It lists 0 as selecting COMP128v1 and 1 as selecting COMP128v2, and these two codes are correct - confirmed by programming these codes, doing a RUN GSM ALGO command, and comparing returned SRES and Kc against osmo-auc-gen. However, the page lists 3 as selecting COMP128v3, and this part is not correct - writing 3 in there results in COMP128v2 being selected, just like code 1. Instead I need to write 2 into the lower nibble of this byte in order to get COMP128v3 SRES and Kc in response to RUN GSM ALGO. * The COMP128 selection code is just the lower nibble of byte 3 of EF.WEKI - the upper nibble is something else that currently eludes my understanding. The wiki page instructs users to write 0 into the upper nibble, and so does pySim-prog - yet in the initial "unprogrammed" state of the cards I received from Grcard, this upper nibble is set to 2, not 0. I could not see any observable difference in card behaviour whether the upper nibble is set to 0 or 2 - either way the lower nibble selects COMP128 version for RUN GSM ALGO operations. * The wiki page gives the impression that EF.WEKI is 19 bytes long in total. However, the actual size of this transparent EF on the card is 35 bytes, i.e., there is another 16-byte field (some other key?) after Ki. Of the people who were once privileged with proper official documentation for these cards, might anyone be able to tell what this other key is for? Could it perhaps be some kind of key for OTA? Before someone tells me that I should direct these questions to Grcard, given that I am buying cards from them, let me assure everyone that yes, of course I am doing everything I can to pry this information out of them. However, they seem to have the same attitude as most Chinese companies where they just want you to buy their product and not ask any technical questions, and whatever answers they do give are so terse that they feel like non-answers. But there is also the undeniable fact that once upon a time these cards were resold by Sysmocom, once upon a time this Osmocom community right here worked with these cards, and someone in this community (or on Sysmocom staff) must have gotten enough documentation to write the wiki page and pySim-prog support for them. Thus I feel at least somewhat justified in asking this community for help with bringing back this lost knowledge. On a happier note, my fc-pcsc-tools suite (fc-simtool and its limited- function companion fc-uicc-tool) is advancing quite a bit in functionality. I don't know how it compares to pysim-shell since I gave up trying to get the latter to run under Slackware (just too many difficult dependencies), but from what I read in mailing list posts, pysim-shell seems to be rather UICC-centric - I couldn't tell if it is supposed to work on non-UICC GSM 11.11 protocol cards or not. In contrast, my fc-simtool (written in C, zero dependencies beyond libpcsclite) speaks the classic GSM 11.11 SIM protocol and does everything that is possible within this protocol, including innovative hacks like brute force search of the file ID space. This tool should be ideal for cards like GrcardSIM2 which are non-UICC and for which the classic GSM 11.11 SIM protocol is native. The companion utility fc-uicc-tool for the UICC protocol is quite minimal in functionality, just enough to satisfy the few areas of curiosity I had in relation to that protocol and the cards I have around that speak it. These new C-language SIM tools live here: https://www.freecalypso.org/hg/fc-pcsc-tools/ The code is 100% my own original work and there is a LICENSE file at the top of the repository declaring it as public domain, so there should be no problem with Free Software status of the work. In hacking fellowship, Mother Mychaela

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Jenkins: 2 new raspberry pi nodes / running on raspbian10
by Oliver Smith 08 Mar '21

08 Mar '21

Hey all, short FYI regarding jenkins.osmocom.org: two new raspberry pi nodes are available, in order to reduce wait times for free build slots during heavy osmo-trx development. All three pis execute the jenkins jobs on top of raspbian10 now, unlike the old setup where it was on top of debian 9 in a LXC running in raspbian10. In other words, the LXC layer is gone now, and there might be slight differences related to debian9 vs. debian 10 packages. For all the jobs running in docker instead of directly on the host, there should be no difference at all. Details are in OS#5055. Best, Oliver -- - Oliver Smith <osmith(a)sysmocom.de> https://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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OpenBSC March 2021