OpenBSC November 2011

openbsc@lists.osmocom.org

21 participants
25 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

4 5

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.

4 3

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

4 3

RFC: Osmocom developer workshop 2012
by Harald Welte 14 Dec '11

14 Dec '11

<DISCLAIMER> Please follow-up to openbsc(a)lists.osmocom.org </DISCLAIMER> Hi all, this idea has been around for quite some time, and for 2012 I really want to turn it into reality: I'd like to have a Osmocom developer workshop The idea here is to get all the active contributors of the project together for a couple of days (maybe 2-4 days), in order to exchange ideas, get to know each other better and last but not least work together on ironing out some of the more difficult issues. * City: Regarding the location: I think for me it is only possible to organize it if it is to be held in Berlin. I'mn happy if somebody else wants to host it at some other location, but then that person would also have to take care of local organization. Berlin also has good train and flight connections, which is definitely a plus. * Venue: If it is in Berlin, we might consider talking with c-base or Raumfahrtagentur as possible venues. * Date: Regarding a proposed date, I'm completely open for suggestions. Of course there shouldn't be any overlap with other major FOSS or Sescurity related conferences, and it should also not coincide with major public holidays, as that only makes travel + accomodation more expensive. * Funding: As we don't have that many commercial users of Osmocom projects, getting funding for e.g. travel / accomodation is probably going to be difficult. We can ask the "usual suspects" among those commercial users we know,, but I guess it will only be possible in exceptional cases to provide that kind of funding. Any ideas / comments / feedback is much appreciated. If somebody has a particular suggestion. <DISCLAIMER> Please follow-up to openbsc(a)lists.osmocom.org </DISCLAIMER> Cheers, 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)

7 13

Time in MM Info [patch]
by Gus Bourg 01 Dec '11

01 Dec '11

Attached is a patch to support sending time to the device. It adds two per-bts configuration elements: tzunits and tzdir. tzunits are the number of units from GMT. Each unit represents 15 minutes of time. tzdir is the direction of the units from GMT. tzdir 0 means GMT-tzunits and tzdir 1 means GMT+tzunits. So for example, if you're GMT+1 you want: bts 0 type nanobts band PCS1900 cell_identity 0 location_area_code 1 training_sequence_code 7 base_station_id_code 63 tzunits 4 tzdir 1 ms max power 15 cell reselection hysteresis 4 Thanks, Gus

3 5

RFC: Generic (U)SIM software
by Harald Welte 29 Nov '11

29 Nov '11

Hi all, I'm thinking of starting a project that would allow us to * perform SIM and USIM card pre-personalization * read/dump and explore [U]SIM contents interactively * perform SIM card simulation The idea is to start with some generic data structure that can represent the filesystem tree (DFs, EFs) and their "external" properties, i.e. file type, size, permissions, FID, SFID, etc. This data structure could also have the actual file content associated with each EF. The second step would be some code that can take that data structure and program a freely-programmable card (like sysmoSIM-GR1) and create the files according to that structure. Another module would implement card-simulation (via BT SAP, SIMtrace or virtual PC/SC card). After all, only a few instructions have to be imilpemented if the filesystem and its content is already in a generic data structure that the program can access.. Next step would be to associate parser and generator routines for the content of each individual file as it is specified in TS 11.11. After that has been done, we could think of representing the FS tree and the parsed contents of each file in some kind of graphical / user friendly representation. The idea here is that the UI code would be generic and not know any of the actual ecnoding/decoding of the EF content. The biggest question is what language to use for this. Some kind of object orientation might very well resemble the idea of a 'file object' in a tree, with many different file types, each having it's own parser/encoder. On the other hand, Erlang's bit field syntax would probably come very handy in terms of encoding/decoding the various EF content. However, at least once we start to want some kidn of UI, Erlan really sucsk. Also, almost nobody here reads/writes Erlang [yet?]. Writing all this in C seems like a bit much of an effort, probably even more so on the UI side. However, we already have quite a bit of C code for parsing/generating things like LAI, etc. which are stored like 04.08 inside the sim card files. Python might be a good idea in terms of tons of available libraries/modules, object orientation and good UI bindings. The biggest problem here is that my python skills are really limited so far, so my productivity might not be as high as I expect. The individual components could even be written in different languages, but then we would have to have some common format for exchanging data back and forth - which might not be worth it, given the small scope of the project. any ideas / comments / feedback? -- - 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)

5 7

[PATCH] fix two mistakes in AM_LDFLAGS
by Alexander Huemer 25 Nov '11

25 Nov '11

--- openbsc/src/libgb/Makefile.am | 2 +- openbsc/src/libmsc/Makefile.am | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/openbsc/src/libgb/Makefile.am b/openbsc/src/libgb/Makefile.am index 8ec1006..c98cad7 100644 --- a/openbsc/src/libgb/Makefile.am +++ b/openbsc/src/libgb/Makefile.am @@ -1,6 +1,6 @@ INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir) AM_CFLAGS=-Wall -fno-strict-aliasing $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(COVERAGE_CFLAGS) -AM_LDFLAGS = $(LIBOSMOCORE_LIBS) $(LIBOSMOCORE_GSM) $(LIBOSMOVTY_LIBS) $(COVERAGE_LDFLAGS) +AM_LDFLAGS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) $(COVERAGE_LDFLAGS) noinst_LIBRARIES = libgb.a diff --git a/openbsc/src/libmsc/Makefile.am b/openbsc/src/libmsc/Makefile.am index 8d5034c..5e64453 100644 --- a/openbsc/src/libmsc/Makefile.am +++ b/openbsc/src/libmsc/Makefile.am @@ -1,6 +1,6 @@ INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir) AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(COVERAGE_CFLAGS) -AM_LDFLAGS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_CFLAGS) $(COVERAGE_LDFLAGS) +AM_LDFLAGS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(COVERAGE_LDFLAGS) noinst_LIBRARIES = libmsc.a -- 1.7.8.rc1

2 1

paralell multipart sms not working
by Dennis Wehrle 24 Nov '11

24 Nov '11

Hi Our plan is to offer an subscription to get our mensa menu via sms. If just one MS get the sms everything works fine. But if two MSs are online and OpenBSC sends the sms paralell (for each TS) something goes wrong. The first two parts for both SMS will be transmitted correctly. But than we receive a malformed packet from the BTS (see No. 103 from wrong-sms.xml). After that the MS seems to be "confused" or something else is wrong, because the following parts (and part 2) will be transmitted several times. This is because the MS don't ack the sms correctly. On a previous test we get 14 sms parts instead of just 5 parts: 1. part: 1 times 2. part: 2 times 3. part: 3 times 4. part: 4 times 5. part: 4 times Attached are two gammu-logfiles. right-sms.xml: Only one MS is online and the sms is transmitted correctly. wrong-sms.xml: Two MSs are online. In the logfile you can only see one MS. Until packet No. 102 everything seems to be OK. ATM i don't know were to search on the code. I don't think there is a sms bug. I think there is a memory bug, because the packet No 103 seems to be random (or contains previous data). Maybe someone can give me an advice. Thanks in advance Dennis Wehrle

4 10

GPRS with OpenBSC problem
by Radko Krkoš 14 Nov '11

14 Nov '11

Hello, I am trying to set up an OpenBSC based GSM network. The GSM part was easy and relatively quick to do, but I have a problem with GPRS. I have read the documentation for OpenSGSN (http://openbsc.osmocom.org/trac/wiki/) and OpenGGSN (man page). After a couple of days searching for more information and trying whatever came to my mind, GPRS still does not work. BTS is ip.access nanoBTS, using IP address 192.168.2.3 (was set up like that, I got it second hand). It is connected to eth1 (192.168.2.1). The PC is running osmo-nitb, osmo-sgsn and ggsn (started in reverse order). Interface eth0 is internet connection (behind NAT). ********** bash-4.1# ifconfig eth0 Link encap:Ethernet HWaddr 00:22:15:99:86:2E inet addr:192.168.110.34 Bcast:192.168.110.255 Mask:255.255.255.0 inet6 addr: fe80::222:15ff:fe99:862e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:22233 errors:0 dropped:1314 overruns:0 frame:0 TX packets:4200 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:4119511 (3.9 Mb) TX bytes:514598 (502.5 Kb) Interrupt:20 Memory:f9fc0000-f9fe0000 eth1 Link encap:Ethernet HWaddr 00:E0:7D:D6:7D:2D inet addr:192.168.2.1 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::2e0:7dff:fed6:7d2d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7311 errors:0 dropped:0 overruns:0 frame:0 TX packets:7211 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:630759 (615.9 Kb) TX bytes:445274 (434.8 Kb) Interrupt:17 Base address:0xe800 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:8 errors:0 dropped:0 overruns:0 frame:0 TX packets:8 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:480 (480.0 b) TX bytes:480 (480.0 b) lo:1 Link encap:Local Loopback inet addr:192.168.3.2 Mask:255.255.255.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 lo:2 Link encap:Local Loopback inet addr:192.168.3.3 Mask:255.255.255.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 inet addr:192.168.254.1 P-t-P:192.168.254.1 Mask:255.255.255.0 UP POINTOPOINT RUNNING MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) ********** bash-4.1# cat /proc/sys/net/ipv4/ip_forward 1 ********** I have also added a rule to iptables: iptables -A POSTROUTING -s 192.168.254.0/24 -t nat -o eth0 -j MASQUERADE ********** Here are my configuration files: ********** GPRS section of nitb.conf: ********** gprs mode gprs gprs routing area 0 gprs cell bvci 2 gprs nsei 101 gprs nsvc 0 nsvci 101 gprs nsvc 0 local udp port 23000 gprs nsvc 0 remote udp port 23000 gprs nsvc 0 remote ip 192.168.2.1 ********** sgsn.conf: ********** ! ! Osmocom SGSN configuration ! line vty no login ! sgsn gtp local-ip 192.168.3.2 ggsn 0 remote-ip 192.168.3.3 ggsn 0 gtp-version 1 ! ns timer tns-block 3 timer tns-block-retries 3 timer tns-reset 3 timer tns-reset-retries 3 timer tns-test 30 timer tns-alive 3 timer tns-alive-retries 10 encapsulation udp local-ip 192.168.2.1 encapsulation udp local-port 23000 encapsulation framerelay-gre enabled 0 ! bssgp ! ********** ggsn.conf: ********** pidfile /var/run/ggsn.pid statedir /var/lib/ggsn/ listen 192.168.3.3 net 192.168.254.0/24 dynip 192.168.254.0/24 timelimit 0 I am using Wireshark with patches from openbsc git applied. GSM calls and SMS work fine. BTS is able to connect to SGSN, as can be seen from the output: ********** rado@openbsc:~$ osmo-sgsn -c sgsn.conf <0011> gprs_ns.c:151 NSVCI=65534 Creating NS-VC <0011> gprs_ns.c:151 NSVCI=65535 Creating NS-VC <0011> gprs_ns.c:738 Creating NS-VC for BSS at 192.168.2.3:23000 <0011> gprs_ns.c:620 NSEI=65535 Rx NS RESET (NSVCI=0, cause=O&M intervention) <0011> gprs_ns.c:488 NSEI=101 Tx NS RESET ACK (NSVCI=101) <0011> gprs_ns.c:797 NSEI=101 Rx NS UNBLOCK <0012> gprs_bssgp.c:246 BSSGP BVCI=0 Rx RESET cause=Transmission capacity modified <0012> gprs_bssgp.c:246 BSSGP BVCI=2 Rx RESET cause=O&M intervention <0012> gprs_bssgp.c:269 Cell 230-10-1209-0 CI 2984 on BVCI 2 <0012> gprs_bssgp.c:322 BSSGP BVCI=2 Rx BVC-UNBLOCK <0012> gprs_bssgp.c:462 BSSGP BVCI=2 Rx Flow Control BVC ********** When trying to use GPRS from mobile phone: ********** <0012> gprs_bssgp.c:346 BSSGP TLLI=0x7ed21cb5 Rx UPLINK-UNITDATA <0013> gprs_llc.c:478 LLC SAPI=1 C FCS=0x17cd30CMD=UI DATA <0013> gprs_llc.c:741 LLC RX: unknown TLLI 0x7ed21cb5, creating LLME on the fly <0012> gprs_bssgp.c:346 BSSGP TLLI=0x7ed21cb5 Rx UPLINK-UNITDATA <0013> gprs_llc.c:478 LLC SAPI=1 C FCS=0x17cd32CMD=UI DATA <0012> gprs_bssgp.c:346 BSSGP TLLI=0x7ed21cb5 Rx UPLINK-UNITDATA <0013> gprs_llc.c:478 LLC SAPI=1 C FCS=0x17cd4cCMD=UI DATA and so on until phone timeouts. The problem is in my opinion between SGSN and GGSN, as no data is transferred through the tunnel (or the lo interface). But I checked the settings multiple times and tried other configurations (alias for eth1). Openbsc, openggsn, libosmocore, libosmo-abis are all compiled from git repositories. I do not understand what I am doing wrong and I am out of options. So I am asking for help. Thank you for your time. Rado Krkos

3 3

GPRS with OpenBSC
by Krkos Radko 14 Nov '11

14 Nov '11

1 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

OpenBSC November 2011