OpenBSC March 2011

openbsc@lists.osmocom.org

20 participants
57 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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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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sms bugfix
by Dennis Wehrle 25 Jul '11

25 Jul '11

Hello Our goal was to send status sms via the vty interface. But all of our sms were cropped. In contrast sms from one MS to another MS are displayed correctly (despite the fact, that the text at the database contains several '@' at the end / the user_data contains several zero-octets). Therefore i have inspect the code and found several bugs. The main problem is that the "user_data_len" is not correctly used. As per GSM 03.40, 9.2.3.16 TP‑User‑Data‑Length (TP‑UDL): "If the TP‑User‑Data is coded using the GSM 7 bit default alphabet, the TP‑User‑Data‑Length field gives an integer representation of the number of septets within the TP‑User‑Data field to follow." Currently the "user_data_len" contains the number of octets (returned from gsm_7bit_encode(...) at gsm_utils.c (libosmocore)). The big problem here is that this information is not unique, e.g.: 1.) 46 non-extension characters + 1 extension character => (46 * 7 bit + (1 * (2 * 7 bit))) / 8 bit = 42 octets 2.) 47 non-extension characters => (47 * 7 bit) / 8 bit = 41,125 = 42 octets 3.) 48 non-extension characters => (48 * 7 bit) / 8 bit = 42 octects But the MS has to know the correct "user_data_len" to decode the correct number of characters. For this reason i updated the gsm_7bit_encode() function to return the correct number of septets. However sometimes it is needed to know the correct number of octets (e.g. at gsm_04_11.c: gsm340_gen_tpdu(...)) => i added a function to gsm_utils.c named: uint8_t get_octet_len(const uint8_t sept_len) I have also fixed the problem, that the sms are wrongly stored / displayed on the database. But the solution on the function *sms_from_result(...) (at db.c) is not really "beautiful". This is because there exists no "user_data_len" field at the database. To store the right value for "user_data_len" (which is further needed) i have to get the length from the "text" field. Unfortunately this is not enough. If the text contains extension characters like {[]} etc. then the "user_data_len" has to be bigger because these characters needs two septets. Therefore i use a switch statement so search for these characters. A better solution for that is to store the right "user_data_len" to the database (on the encoding / decoding procedure). But i don't know if this is a suitable solution for all of you (because you have to change your database structure etc.). Best Regards Dennis Wehrle

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wireshark: update of RSL dissector
by pablo＠gnumonks.org 11 Apr '11

11 Apr '11

From: Pablo Neira Ayuso <pablo(a)gnumonks.org> This patch includes some updates for the wireshark RSL dissector. See patch for details. This changes are available in the pablo/wireshark-rsl branch of openBSC. Please, merge it. Pablo Neira Ayuso (1): wireshark: update extension of RSL dissector with ip.access nanoBTS support wireshark/0004-rsl-ipaccess.patch | 228 ++++++++++++++++++++++--------------- 1 files changed, 134 insertions(+), 94 deletions(-) -- 1.7.2.3

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RTP-Proxy without MNCC-BuildIn no running
by meckel＠netzing.de 30 Mar '11

30 Mar '11

Hi List I want to use OpenBSC with Asterisk and LCR. After a lot of reading I found out that openbsc must start with the Paramters "-m" and "-P". But i got a lot error messages like: <0006> gsm_04_08.c:2960 receive message GSM_TCH_FRAME <0006> gsm_04_08.c:2992 TCH frame to lchan without RTP connection So i tried a lot and start only with -P and the RTP-Proxy started. But LCR and Asterisk sure not involved because the missing "-m". So i need "-m". It is a bug or a feature that "-P" will be ignored if I set "-m"? I´m sitting over the bsc code but until this moment I didnt found something so I hope somebody here can help. Ulrich Meckel

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Problem with RTP-Proxy
by Luca Bertoncello 29 Mar '11

29 Mar '11

Hi, list! We are trying to connect OpenBSC and Asterisk together (through LCR), but we have many problems. We start OpenBSC with the parameters -P -m --debug=DRLL:DCC:DMM:DRR:DRSL:DMNCC:DMSC:DNM:DLCH:DMUX:DHO Now, if we try to call a mobile phone from another one, we get many errors: <0006> gsm_04_08.c:2960 receive message GSM_TCH_FRAME <0006> gsm_04_08.c:2992 TCH frame to lchan without RTP connection Now, if I understand what mncc_tx_to_cc does, I can just think, that the RTP-Proxy is NOT active, but a part of OpenBSC thinks that it IS active. Another interesting problem is, that, although we start OpenBSC to debug the CC, we do NOT get a message like: Setting up TCH map between ... (gsm_04_08.c line 1606) Could someone confirm me my idea? And, maybe, give me a suggestion to fix our problem? We use OpenBSC in the version 0.9.11.375-ca8f. Thanks a lot in advance for your help Luca Bertoncello -- _______________________________________________________________________ Luca Bertoncello Entwicklung Mail: bertoncello(a)netzing.de NETZING Solutions AG Tel.: 0351/41381 - 23 Fröbelstr. 57, 01159 Dresden Fax: 0351/41381 - 12 _______________________________________________________________________ Impressum: NETZING Solutions AG - Fröbelstraße 57 - 01159 Dresden Sitz der Gesellschaft Amtsgericht Dresden HRB 18926 Vorstand Dieter Schneider - Aufsichtsratsvorsitzender Volker Kanitz USt.Id DE211326547 Mail: netzing.ag(a)netzing.de

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[PATCH 0/4] libosmocore: several cleanups
by pablo＠gnumonks.org 28 Mar '11

28 Mar '11

From: Pablo Neira Ayuso <pablo(a)gnumonks.org> This patchset includes several cleanups previous to another patchset that will contain the namespace pollution fix (to appear soon). They're available in the branch pablo/cleanups in libosmocore. Please merge it. Pablo Neira Ayuso (4): bitvec: add bitvec_find_first_bit_pos() from gsm/rxlev_stat.c write_queue: use full path of includes in osmocom/core/write_queue.h vty: move vty_out_rate_ctr_group prototype to osmocom/vty/misc.h utils: move OSMO_SNPRINT_RET() macro definition to osmocom/core/utils.h include/osmocom/core/bitvec.h | 2 ++ include/osmocom/core/rate_ctr.h | 3 --- include/osmocom/core/utils.h | 9 +++++++++ include/osmocom/core/write_queue.h | 4 ++-- include/osmocom/vty/Makefile.am | 2 +- include/osmocom/vty/misc.h | 10 ++++++++++ src/bitvec.c | 14 ++++++++++++++ src/gsm/rxlev_stat.c | 12 ------------ src/logging.c | 26 ++++++++------------------ 9 files changed, 46 insertions(+), 36 deletions(-) create mode 100644 include/osmocom/vty/misc.h -- 1.7.2.3

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[PATCH] [RFC] src: add prefix osmocom_ to all functions in libosmocore
by pablo＠gnumonks.org 28 Mar '11

28 Mar '11

From: Pablo Neira Ayuso <pablo(a)gnumonks.org> This patch is a RFC, I can add the prefix osmocom_ to all functions in libosmocore to fix with the existing namespace pollution. This task was proposed by Harald. Let me know if you are OK with this approach and I'll send a patchset along this week. --- include/osmocom/core/backtrace.h | 2 +- src/backtrace.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/osmocom/core/backtrace.h b/include/osmocom/core/backtrace.h index bbbb2c2..7c248aa 100644 --- a/include/osmocom/core/backtrace.h +++ b/include/osmocom/core/backtrace.h @@ -1,6 +1,6 @@ #ifndef _OSMO_BACKTRACE_H_ #define _OSMO_BACKTRACE_H_ -void generate_backtrace(); +void osmocom_generate_backtrace(); #endif diff --git a/src/backtrace.c b/src/backtrace.c index ecd6b9c..5c609bb 100644 --- a/src/backtrace.c +++ b/src/backtrace.c @@ -29,7 +29,7 @@ #ifdef HAVE_EXECINFO_H #include <execinfo.h> -void generate_backtrace() +void osmocom_generate_backtrace() { int i, nptrs; void *buffer[100]; -- 1.7.2.3

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[PATCH] openBSC: include new file osmocom/vty/misc.h in several daemons
by pablo＠gnumonks.org 28 Mar '11

28 Mar '11

From: Pablo Neira Ayuso <pablo(a)gnumonks.org> Minor change in openBSC due to new osmocom/vty/misc.h file that was added in the patchset entitled: libosmocore: several cleanups It's available in pablo/cleanups branch in openbsc git tree. Please, merge it. Pablo Neira Ayuso (1): src: include new file osmocom/vty/misc.h for vty_out_rate_ctr_group() openbsc/src/gprs/sgsn_vty.c | 1 + openbsc/src/libgb/gprs_bssgp_vty.c | 1 + openbsc/src/libgb/gprs_ns_vty.c | 1 + openbsc/src/osmo-bsc_nat/bsc_nat_vty.c | 1 + 4 files changed, 4 insertions(+), 0 deletions(-) -- 1.7.2.3

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OpenBSC March 2011