January 2013 - OpenBSC - lists.osmocom.org

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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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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Re: Any interest for Osmocom meetings in Bavaria ?
by Dieter Spaar 11 Jun '13

11 Jun '13

So far three persons have indicated their interest to join a meeting at my place. Considering the time it takes to drive to my place, it probably makes sense to have the meeting at the weekend (either Saturday or Sunday) so that there is more time for the meeting itself. I can suggest one of the following dates for the first meeting, somewhere between 10:00 to 18:00 on each day: 25.8. (Sa) or 26.8. (Su) 1.9. (Sa) or 2.9. (Su) 8.9. (Sa) or 9.9. (Su) So please let me know when you have time and also make suggestions in which Osmocom topic you are interested in so that we can have some sort of agenda for the meeting to make best use of the time. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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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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OpenBSC with LCR/SIP
by Kelum Navaratne 26 Jan '13

26 Jan '13

Hello list, First of all congratulation to developers of this project making such wonderful project in an interesting subject. I am new to this project and for past few days i managed to go through the documentation and get most of it tested. Thanks for pretty good documentation in most of the areas as well. I have the osmo-nitb working very fine using a nano bts. How ever when i try to install it with LCR to interconnect with external switch, im facing some problems. Initially i thought i must use LCR+Asterisk. But later i figured out there is a built in SIP interface on LCR which there is no need to asterisk or chan_asterisk. I would prefer to use this LCR SIP interface as i dont want to use asterisk and just want to forward all calls to another SIP switch. Now in this context there seems absolutely no documentation on both openbsc and LCR/mISDN lists. Can some one please shed me some light here on how to build a LCR with SIP to be work with osmo-nitb. All i want to test is GSM phone > Osmo-nitb > LCR with SIP > SIP softswitch Thank you very much for every one's effort in this project and would be glad to see some response for this. Best Regards Nava.

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None
by FABIAN SMITH 25 Jan '13

25 Jan '13

http://www.arts-gallery.de/tmp/likemn.html FABIAN SMITH

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nanoBTS Booster for sale
by Konrad Meier 23 Jan '13

23 Jan '13

Hi all, At the University of Freiburg (Germany) we have a nanoBTS booster 1800 for sale. Details for the booster are given here: http://www.proximus.com.ua/Nano_BTS_high_power_GSM_booster.html The package includes everything required: - Booster - Power supply - 2x cable to connect to the nanoBTS (0,5 meter) - 1x cable to the antenna (5 meter) - 1x omnidirectional antenna. 3 dBd gain / 1800 MHz The antenna is a high quality omnidirectional antenna from Procom: http://www.procom.dk/products/base-station-antennas/1.3-2.0-ghz/gain-antenn… Best regards Konrad Meier

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Jan 23, 8pm / Osmocom Berlin User Group meeting
by Harald Welte 21 Jan '13

21 Jan '13

Hi all! This is the announcement for the latest incarnation of our bi-weekly Osmocom Berlin meeting. January 23, 8pm @ CCC Berlin, Marienstr. 11, 10113 Berlin There is no formal presentation scheduled for this meeting. However, we'll have a progress report + demonstration of current osmo-pcu. If you are interested to show up, feel free to do so. The meeting is free as in "free beer", despite no actual free beer being around ;) 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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Review request for osmo-bts changes for my zecke/channel-release branch
by Holger Hans Peter Freyther 17 Jan '13

17 Jan '13

Hi, the branch is not done yet but I am confident about the first couple of commits and would like to have some extra eyes to take a look. The branch is here[1] and the general goal is to improve the reliability of the code. Under heavy use it is possible that the nitb will mark all lchans as broken. While doing the tests I noticed the following issues: 1.) On Call-Control with fast hangups (during channel modify) I can see empty FACCH messages from the DSP gsm queue. 2.) The wlc/prim request handling has the known and documented limitation that for a given confirm we do not know who sent the request. This can lead to call the 'wrong' callback with the wrong data/closure. I addressed this the following way: 1.) Add a u8Size == 0 check. For the SACCH we added a < 2 check. Should we check if a LAPDm header could fit? What would be the best limit? I have only seen u8Size == 0, so this is what I addressed.[2] 2.) I address it by passing the gsm_bts_trx as the data pointer and saving the lchan identifier in the hLayer3 pointer and then resolve the lchan from the TS. In follow up commits I introduced a new function to enter the Gsm primitive into the queue and I plan to change the callback signature for them to always include the TRX anyway. The main change is here[3]. There is still a clash between the Ciphering and the TxPower... 3.) The next commits should fix the reliability issue. I do this by keeping a queue of outstanding SAPI operations. And ACK ABIS requests when the queue becomes empty. This is mostly working right now but I have one issue with the ChannelReleaseMarker. When sending a SACCH DEACTIVATE and before the two SACCHs are deactivated send a RF Channel Release the queue appears to be stuck. cheers holger [1] http://cgit.osmocom.org/cgit/osmo-bts/log/?h=zecke/channel-release [2] http://cgit.osmocom.org/cgit/osmo-bts/commit/?h=zecke/channel-release&id=2e… [3] http://cgit.osmocom.org/cgit/osmo-bts/commit/?h=zecke/channel-release&id=af…

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Documentation for Control interface in wiki?
by Harald Welte 17 Jan '13

17 Jan '13

Hi Daniel, today I was creating http://openbsc.osmocom.org/trac/wiki/PortNumbers and realised that there is no wiki page describing what the control protocol is (which I would ahve linked from PortNumbers). I know at the time you first posted the control interface patches to the list, there was some README/Documentation. Could you please add that to a wiki page, possibly reviewing/updating it to reflect today's control interface? Thanks in advance, 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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