OpenBSC March 2012

openbsc@lists.osmocom.org

31 participants
36 discussions

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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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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SimpleHLR: A web interface for OpenBSC
by Peter Caprioli 03 Jun '13

03 Jun '13

Hello everyone, I've just finnished writing together a small web interface for the OpenBSC HLR. It allows you to modify various parameters in the database and also provides a set of functions to modify the HLR or sending SMSes in your own scripts. The project is still very alpha but it seems to work reasonably good. Feel free to give any feedback! Screenshots and source code is available on my website: https://stormhub.org/simplehlr/ -- *Best regards, Peter Caprioli*

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Several questions
by jason mercury 06 Dec '12

06 Dec '12

I have some questions: 1) When I start bsc_hack bsc_init.c first establishes OML link and initializes the bts then it establishes RSL link and bts starts broadcasting. However, it takes so much time to start the bts. Instead of this I want to do the following: it establishes OML link at the beginning and only once, then when i want to start broadcasting it establishes just the RSL link and bts will start faster since i don't have to wait for OML link. What should be done for this? 2) If i send one or two word messages from telnet interface it is okay. But if i send a longer message the phone could't receive the end of the message correctly(last words may be incomplete). Did any one encounter with this problem? What is wrong with me? 3) Could I send SMS in which extension of the sender is text not integer. For example, i want to send an information SMS that this is a test network. For this purpose i want to send an SMS from 'OpenBSC'. I set the extension of the first subscriber in database as text and tried to send the SMS but SMS wasn't delivered. What should i do? 4) Can i add SMS externally to SMS table of database? Thanks. Jason

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Re: Recording / Re: Regular Osmocom meeting in Berlin?
by Katrin Verclas 01 Apr '12

01 Apr '12

It was my understanding from your suggestion that there would be presentations and discussions after those presentations at the meetings, making this not just having a beer with friends but more formal affairs. That would be useful for people elsewhere to see, given that this is a global community. Not sure what German law has to do with putting online or streaming such presentations. Cameras off when it comes to the informal part and beer time.. Love this list otherwise. And will come to Berlin this summer so may attend one or two, regardless :) Cheers from New York. K ------Original Message------ From: Harald Welte To: Katrin Verclas Cc: Holger Hans Peter Freyther Cc: Akib Sayyed Cc: baseband-devel(a)lists.osmocom.org Cc: openbsc(a)lists.osmocom.org Subject: Recording / Re: Regular Osmocom meeting in Berlin? Sent: Mar 31, 2012 8:01 AM Hi Katrin, On Fri, Mar 30, 2012 at 07:17:17PM +0000, Katrin Verclas wrote: > Could not disagree more. We live-stream local events all the time with > a very unobtrusive webcam/ustream and it bothers no one who is there > but benefits all who are not. And I couldn't disagree more with you. The mere existance of the two words 'camera' and 'unobtrusive' in one sentence are a contradiction in terms. If I want to meet with a small group of people and informally discuss technical topic, than that is _very_ different from being live streamed to an unknonwn number of people, any of which could make recordings and I would have to very carefully think about each and every word that I'm saying. That's not a particularly relaxed environment and would kill all the fun there is in having the meeting in the first place. Legally, In Germany this corresponds to "not publicly spoken word" (nicht oeffentlich gesprochenes Wort). It is punishable under law to record or broadcast that. (Clause 201 of German criminal code). 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) Sent via mobile. Hence, short.

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Re: Regular Osmocom meeting in Berlin?
by Katrin Verclas 31 Mar '12

31 Mar '12

Could not disagree more. We live-stream local events all the time with a very unobtrusive webcam/ustream and it bothers no one who is there but benefits all who are not. Best, Katrin ------Original Message------ From: Holger Hans Peter Freyther Sender: baseband-devel-bounces(a)lists.osmocom.org To: Akib Sayyed Cc: baseband-devel(a)lists.osmocom.org Cc: openbsc(a)lists.osmocom.org Subject: Re: Regular Osmocom meeting in Berlin? Sent: Mar 30, 2012 3:13 PM On 03/30/2012 07:27 PM, Akib Sayyed wrote: > even i am in.people who cannot participate please make some > arrangement for them like live streaming and chat support. > <http://www.ustream.tv/ support free live streaming> Hi, I don't think this is a good idea. It kills the local atmosphere without having any real benefit. Every decision/code and most likely slides will be public anyway. z. Sent via mobile. Hence, short.

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Regular Osmocom meeting in Berlin?
by Harald Welte 31 Mar '12

31 Mar '12

Hi all, I was pondering to start a regular Osmocom meeting (monthly or bi-weekly) in Berlin. The idea would be not only to converge the existing developers in Berlin (zecke, roh, prom, tobias, peter, kevin, myself, ...) but to also try to share some knowledge and excitement with other interested hackers in the wider community. A split format for the event might make sense: Have a more or less organized 45min talk about one particular topic + 15min discussion and then switch to an informal meeting style without any particular topic or moderator. For the first half there is a long list of topics intended at informing people about the status and capabilities of the respective projects: OsmocomBB, OsmoTETRA, OsmoGMR, SIMtrace, etc. Regarding the venue, I would suggest to hold it at the Berlin CCC. What do you generally think about this? What day of the week should we be aiming at? Tuesday and Thursday is generally not a good idea, as those are already occupied with other events. If you think it's a good idea, I would request/register the event with the CCC Berlin. 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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Re: Regular Osmocom meeting in Berlin?
by Zsombor 30 Mar '12

30 Mar '12

Can you record the video about the presentations and upload to some video sharing site ? I'm certain, that there would be some interest watching it :) Thanks, Zsombor On 2012.03.30. 13:33, "Tobias Engel" <t-openbsc(a)tobias.org> wrote: On 29.03.2012 21:41, Peter Stuge wrote: > Harald Welte wrote: >> I was pondering to start a regular ... I would say monthly is more realistic. But I'm also fine with bi-weekly. >> What day of the week should we be aiming at? > > I like Wednesday. Me too. -Tobias

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Call for participation LSM/RMLL
by Mathias Coinchon 29 Mar '12

29 Mar '12

Dear Osmocom community, This email to inform you that the call for participation for the next Libre Software Meeting (LSM or RMLL: Rencontres Mondiales du Logiciel Libre) ends on 31st March: http://2012.rmll.info/en/participate/call-for-papers This edition will take place in Geneva from 7th to 12th July 2012 (7-8 general public days, 9-12 theme focused, professional). It would be of great interest for the communities to learn about the Osmocom projects in presentations or workshop. Real world applications would be interesting too. So please don't hesitate to directly submit. Don't hesitate also to contact me for more information. Mathias Coinchon

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Question regarding timeouts and RRLP
by Refik Hadzialic 28 Mar '12

28 Mar '12

Dear group members, I would like to ask you a question regarding the timeouts and initiating/allocating an SDCCH channel for a subscriber inside of the GSM network. I am trying to modify some parts of OpenBSC (/openbsc/src/libmsc/rrlp.c) and to implement the MS-based RRLP in OpenBSC (to send assistance data in form of almanac, ephemeris, BTS geolocation data and GPS reference time to the MS). At the moment I use the silent sms to start an RRLP request (send RRLP request + assistance data and then send the silent sms). But if it takes too long to send the assistance data OpenBSC starts from the beginning (send rrlp request + assistance data + sms again). I think this is because OpenBSC waits for an ack from the MS for the silent sms (which has not been sent) and therefore it's a timeout issue. As a quick hack I have modified parts of the code and got the RRLP to work (sent successfully these data and I got a position from the MS). Just for the curious one, I commented out three lines just before the return, in /openbsc/src/libmsc/gsm_04_11.c in the function, gsm411_rx_rp_ack, the following lines: //else //gsm411_release_conn(trans->conn); /* free the transaction here */ //trans_free(trans); and I changed one timer value from 10 to 100, in /openbsc/src/libbsc/bsc_rll.c in the function, rll_establish to: osmo_timer_schedule(&rllr->timer, 100, 0);. As I know what I did was wrong (since changing the timers and not releasing the channel properly influences the whole system) but I just did it for the purpose of testing and to see do I send correct data and does the RRLP work at all. I hope you can give me some hints and guides how to allocate a channel for around 130 seconds and to send the RRLP assistance data within that channel without doing the above tricks. Once everything works properly I will provide the RRLP code. Best regards, Refik Hadzialic

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OpenBSC March 2012