February 2012 - 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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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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mISDN/lcr/asterisk compilation issues
by carcelle 02 Mar '12

02 Mar '12

Dear openbsc folks, i am following up on the osmo-nitb/ggsn/sgsn config running w/ a nanoBTS-1800. i have been trying to get mISDN/lcr to build to be able to create the chan_lcr into asterisk (i am more familiar w/ dahdi/asterisk for isdn cahnnels) though so far i am not able to get it to work : *configuration : **host : running linux debian lenny 2.6.26-2-686) **autoconf 2.61 **mISDN-1_1_9.1 (downloaded as a tarball) builds mISDN_dsp.ko but not mISDN_l1loop.ko **lcr doest not build (./configure passes) /usr/src/lcr# git-apply --verbose lcrOpenBSC.patch Checking patch gsm_bs.cpp... error: while searching for: int bts_model_nanobts_init(void); static struct log_target *stderr_target; /* timer to store statistics */ #define DB_SYNC_INTERVAL 60, 0 static struct timer_list db_sync_timer; error: patch failed: gsm_bs.cpp:39 error: gsm_bs.cpp: patch does not apply /usr/src/lcr# make (...) gcc -DWITH_GSM_BS -I./openbsc/include -I./libosmocore/include -I./openbsc -Wall -DCONFIG_DATA="\"/usr/local/lcr\"" -DSHARE_DATA="\"/usr/local/lcr\"" -DLOG_DIR="\"/usr/local/lcr\"" -DEXTENSION_DATA="\"/usr/local/lcr/extensions\"" -D_GNU_SOURCE -fPIC -c bchannel.c -o bchannel.po bchannel.c:29:31: error: mISDN/mISDNcompat.h: No such file or directory bchannel.c:30: error: 'MISDN_AF_ISDN' undeclared here (not in a function) bchannel.c:31:24: error: mISDN/q931.h: No such file or directory bchannel.c: In function 'bchannel_create': bchannel.c:148: error: 'PF_ISDN' undeclared (first use in this function) bchannel.c:148: error: (Each undeclared identifier is reported only once bchannel.c:148: error: for each function it appears in.) bchannel.c:174: error: 'AF_ISDN' undeclared (first use in this function) make[1]: *** [bchannel.po] Error 1 make[1]: Leaving directory `/usr/src/lcr' (lcr from git : commit 6e1e99808e5b1c16b00904d31f95d0b74487023e) *questions : **do i need misdn to build lcr if running a nanobts w/ Abis-over-ip ? **am i missing something in the build order ? **any packaged version of misdn for debian 2.6.26-2-686 ? thanks for your support. Xavier.

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Re: Specifying channel mode for speech
by Thomas Cooper 29 Feb '12

29 Feb '12

Thank you for the quick and helpful replies, Andreas and Holger! I had a feeling there was an easy answer. -Tom > Message: 6 > Date: Wed, 29 Feb 2012 08:21:13 +0100 > From: jolly <andreas(a)eversberg.eu> > To: Thomas Cooper <tacooper(a)vt.edu> > Cc: openbsc(a)lists.osmocom.org > Subject: Re: Specifying channel mode for speech > Message-ID: <4F4DD1E9.8080409(a)eversberg.eu> > Content-Type: text/plain; charset=ISO-8859-1 > > Thomas Cooper wrote: >> Osmo-bts gets the MODE_MODIFY_REQ from OpenBSC with >> GSM48_CMODE_SPEECH_EFR to use for the channel mode. However, I would >> like to be able to specify using GSM48_CMODE_SPEECH_V1 instead (which >> is FR; EFR is not supported in L1). Is there an easy way to set the >> preferred channel mode/audio support? I didn't see anything on the VTY >> wiki or in the config file. >> > hi tom, > > you may change the line 46 at mncc_builtin.c. the first entry in this > array is the full rate code, the second entry is the half rate codec. > (depending on the trx configuration) just change the first entry to > GSM48_CMODE_SPEECH_V1. > > regards, > > andreas > > ------------------------------ > > Message: 8 > Date: Wed, 29 Feb 2012 09:54:24 +0100 > From: Holger Hans Peter Freyther <holger(a)freyther.de> > To: openbsc(a)lists.osmocom.org > Subject: Re: Specifying channel mode for speech > Message-ID: <4F4DE7C0.5000000(a)freyther.de> > Content-Type: text/plain; charset=ISO-8859-1 > > On 02/29/2012 08:21 AM, jolly wrote: > >> you may change the line 46 at mncc_builtin.c. the first entry in this >> array is the full rate code, the second entry is the half rate codec. >> (depending on the trx configuration) just change the first entry to >> GSM48_CMODE_SPEECH_V1. > > you can change this with the VTY config. Look at commit > ab386e6120559ef2deb6a27f4455539cba920c9d that introduced it. > > holger >

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Re: neighbour cells
by Harald Welte 29 Feb '12

29 Feb '12

Hi Jolly, On Wed, Feb 29, 2012 at 09:21:34AM +0100, jolly wrote: > i improved the generation of neighbour cells of openbsc. the patch is > committed at origin/jolly/rtpmux. Thanks a lot for working on this. It's a really nasty subject with lots of bit-fiddling and many strange cases. > it generated the system information messages of neighbour cells in the > same and in other bands. depending on the location of the bcch and the > neighbour cells, the messages SI 2/5 and optionally SI 2bis/5bis and SI > 2ter/5ter are generated. > > i have tested it with several configurations. i would like to commit it > to master. any suggestions? I've reviewed it, and the patch seems fine to me. I haven't tested it, though. Feel free to commit it to master. And thanks for the verbose changelog message. 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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Specifying channel mode for speech
by Thomas Cooper 29 Feb '12

29 Feb '12

Osmo-bts gets the MODE_MODIFY_REQ from OpenBSC with GSM48_CMODE_SPEECH_EFR to use for the channel mode. However, I would like to be able to specify using GSM48_CMODE_SPEECH_V1 instead (which is FR; EFR is not supported in L1). Is there an easy way to set the preferred channel mode/audio support? I didn't see anything on the VTY wiki or in the config file. Thanks, Tom

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Easterhegg 2012 registration open
by Miguel Elias 27 Feb '12

27 Feb '12

Hi together, the registration for the next Easterhegg in Basel (Switzerland) is open. -->> https://easterhegg.ch We are still looking for workshops and lectures. You can find more information in the attached text file. Here our poster: https://easterhegg.ch/eh2012-plakat-a3.pdf Gruss Miguel aka nobody -- ------------------------------------------------------------------ Chaostreff Basel, Birsfelderstrasse 6, 4132 Muttenz, Schweiz WEB: https://www.chaostreff.ch Wiki: http://wiki.chaostreff.ch Jabber: nobody_su(a)jabber.ccc.de ------------------------------------------------------------------ === Please don't print this e-mail unless you really need to, this is your contribution to save the environment. ===

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SMSC Thoughts
by Harald Welte 25 Feb '12

25 Feb '12

Hi! I'm just writiing this up as you mentioned that you were considering to look into implementing an external SMSC. This is great news, and of course you can do it whatever way you want to do it. However, to put things a bit more into perspective and ensure that this SMSC can also be used in a real GSM core network later on, I would like to ask you to consider staying in line with how the primitives/transacitions look like in a real GSM network. The idea here is that with every new interface we introduce in osmo-nitb, we should try ot move towards that of a real network. This does't mean that it has to implement the actual detailed MAP/TCAP/SCCP encoding as specified, but simply that they semantic of the primitives/messages and their order and time of occurrence is the same.

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