OpenBSC November 2025

openbsc@lists.osmocom.org

17 participants
25 discussions

Need nano3G (S8 - Model 237A)
by Akib Sayyed 18 Jan '26

18 Jan '26

Dear List I am extremely sorry for off the topic question. I am willing to buy nano3G Nodeb. Is anyone in list have spare which can be sold. Please let me know. -- Akib Sayyed Matrix-Shell akibsayyed(a)gmail.com akibsayyed(a)matrixshell.com Mob:- +91-966-514-2243 <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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cmd2 update causing pySim-shell to fail
by bryan coxwell 10 Jan '26

10 Jan '26

Hi all, Just wanted to share an issue and a quick workaround I found for it in case anyone else has the same problem. I believe a cmd2 update is causing pySim-shell to fail. After installing it on a fresh install of Ubuntu Server 20.04 and getting the following error when I run "python3 pySim-shell -p0": >Using PC/SC reader interface >Autodetected card type: sysmoUSIM-SJS1 >AIDs on card: > USIM: a0000000871002ffffffff8907090000 >Traceback (most recent call last): > File "pySim-shell.py", line 512, in <module> > app = PysimApp(card, rs, opts.script) > File "pySim-shell.py", line 59, in __init__ > super().__init__(persistent_history_file='~/.pysim_shell_history', allow_cli_args=False, use_ipython=True, auto_load_commands=False, command_sets=basic_commands, >startup_script=script) >TypeError: __init__() got an unexpected keyword argument 'use_ipython' If you run into this you can fix it by uninstalling cmd2 and reinstalling cmd2 with "pip3 install cmd2==1.5". Best, Bryan

10 11

osmo-gsm-manuals in project repos: I see no .pdf
by Neels Hofmeyr 08 Jan '26

08 Jan '26

Hi Oliver, so I merged the stuff to add the manuals to the individual git repositories, since you said that it works. But when I do --enable-manuals I don't see any PDF files generated. Also a manual 'make pdf' says "nothing to be done". (I probably should have tried it before merging after all) So what am I doing wrong? Alternatively, can you fix it please? ~N

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Excel in NURS FPX 4010 Assessments with Our Expert Online Tutoring
by williammores96＠gmail.com 05 Jan '26

05 Jan '26

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4 6

Move vlr code from osmo-msc into a own library
by Alexander 'lynxis' Couzens 25 Dec '25

25 Dec '25

Hi, a couple month ago I proposed to make the VLR code of the osmo-msc independent of the osmo-msc and create a new library called libosmo-vlr. Later use the libosmo-vlr code to integrate it into osmo-sgsn. But after take more time of this approach, I'm not sure if it is a very good idea to guarantee high stability of libosmo-vlr as we do for other osmocom libraries. Because the code is heavily integrated with both daemon and some code path are quite complex and partly not fully understood. I would rather guarantee runtime stability within a library version, but not at build time. The strategy would be increasing the library major version more often. Any thoughts? Best, lynxis PS. The current concept (because of time pressure) is to keep 2 copies of libosmo-vlr in the code base of osmo-msc and osmo-sgsn and to move it later out of it into an own library.

4 3

Video Recordings of OsmoCon 2017
by Harald Welte 22 Dec '25

22 Dec '25

Hi all, the Osmocom Conference 2017 last week was an overwhelming success. We received lots of positive feedback from all sides. Thanks to all the speakers, to the attendees as well as to the anonymous sponsor of the travel grant funds. It is my great pleasure that due to the great support by C3VOC (The CCC Video Operation Center), we have full recordings of all talks given at OsmoCon 2017. You can find the videos on the C3VOC site at https://media.ccc.de/search/?q=osmocon They are also linked individually from the OsmoCon 2017 homepage at https://osmocom.org/projects/osmo-dev-con/wiki/OsmoCon2017 I hope the video recordings will be of help for everyone who could not make it to the event in person. We will also be collecting the slides and put them up on the wiki during the next few days. Please don't hesitate to raise any feedback and/or questions. Technical feedback/questions regarding Osmocom software / projects should be addressed to the appropriate mailing lists, such as openbsc(a)lists.osmocom.org. Feedback to the organizers should be sent to osmocon2017(a)sysmocom.de. Looking forward to the next OsmoCon, which we'll expect to be spanning ore than just a single day. 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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Managing Complicated Laws in BSC Implementations
by Fennellmarian018＠gmail.com 22 Dec '25

22 Dec '25

The complexities of Base Station Controller (BSC) integration in open-source mobile networks have presented me with a number of overlapping areas pertaining to telecommunications legislation and regulatory compliance. In order to better comprehend how international legal standards affect open BSC installations in various jurisdictions, this intersection has unanticipatedly prompted me to seek [url=https://dissertationwritinghelp.uk/law-dissertation-help/]law dissertation help[/url]. I would love to hear from anyone else who has studied legal issues in their OpenBSC-related academic or practical work, as well as suggest some books.

3 2

Some phones cant receive SMS
by Henry Caga 16 Dec '25

16 Dec '25

Hi, I would like to ask for help regarding my osmo-bsc setup. I have 2 problems as of now. 1) My setup is working fine on my phones, i can send and receive sms. However, on some phones, i can only send sms or call. But i cannot receive sms. I attached the sample logs from the phone that can receive sms and phone that cannot receive sms. I also included my config files. 2) i have a GPSDO TCXO and i wanted to use the maximum setting like setting up the 10mhz reference. what should i set or configure at the config files in order to set it? 3) Is there a way to improve my setup? Im using 50w PA and are there any settings that i have missed? Thank you Henry Phone that can receive sms ========= 20220226175408907 DRLL <0000> chan_alloc.c:240 (bts=0) channel load average is 0.00% 20220226175408907 DRLL <0000> chan_alloc.c:253 (bts=0) T3122 wait indicator set to 10 seconds 20220226175409767 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226175414767 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226175415439 DLSCCP <0020> sccp_user.c:175 Delivering N-UNITDATA.indication to SCCP User 'msc-0' 20220226175415439 DMSC <0007> osmo_bsc_sigtran.c:231 N-UNITDATA.ind(00 16 52 08 08 59 51 20 20 02 00 04 21 09 04 23 1d 63 44 1a 03 05 03 f4 ) 20220226175415439 DMSC <0007> osmo_bsc_bssap.c:1259 Rx MSC UDT: 00 16 52 08 08 59 51 20 20 02 00 04 21 09 04 23 1d 63 44 1a 03 05 03 f4 20220226175415439 DMSC <0007> osmo_bsc_bssap.c:1116 Rx MSC UDT BSSMAP PAGING 20220226175415439 DMSC <0007> osmo_bsc_bssap.c:131 Paging request from MSC BTS: 0 IMSI: '515020220004012' TMSI: '0x231d6344/589128516' LAC: 0x3f4 20220226175416335 DRSL <0003> abis_rsl.c:1383 (bts=0) CHAN RQD: reason: answer to paging (ra=0x9e, neci=0x01, chreq_reason=0x01) 20220226175416335 DRLL <0000> lchan_select.c:173 (bts=0) lchan_select_by_type(SDCCH) 20220226175416335 DRLL <0000> lchan_select.c:87 looking for lchan CCCH+SDCCH4: (bts=0,trx=0,ts=0,pchan=CCCH+SDCCH4,state=UNUSED) ss=0 is available 20220226175416335 DRSL <0003> abis_rsl.c:476 (bts=0,trx=0,ts=0,pchan=CCCH+SDCCH4,state=IN_USE) Tx RSL Channel Activate with act_type=INITIAL 20220226175416662 DMSC <0007> fsm.c:461 SUBSCR_CONN[0x558560323460]{INIT}: Allocated 20220226175416662 DMSC <0007> gsm_08_08.c:489 Tx MSC COMPL L3 20220226175416662 DRSL <0003> gsm_08_08.c:232 RR GSM48_MT_RR_PAG_RESP: TMSI-0x231D6344 matches earlier Paging from msc 0 20220226175416662 DMSC <0007> osmo_bsc_sigtran.c:308 Initializing resources for new SCCP connection to MSC 0: RI=SSN_PC,PC=0.23.1,SSN=BSSAP... 20220226175416663 DMSC <0007> gsm_08_08.c:532 SUBSCR_CONN(msc0-conn4294967295_IMSI515020220004012)[0x558560323460]{INIT}: Received Event MO-CONNECT.req 20220226175416663 DMSC <0007> osmo_bsc_sigtran.c:350 Allocated new connection id: 7 20220226175416663 DMSC <0007> osmo_bsc_sigtran.c:354 Opening new SCCP connection (id=7) to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP 20220226175416663 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-CONNECT.request) 20220226175416663 DLSCCP <0020> fsm.c:461 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: Allocated 20220226175416663 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: Received Event N-CONNECT.req 20220226175416663 DLSCCP <0020> sccp_scoc.c:830 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: state_chg to CONN_PEND_OUT 20220226175416663 DMSC <0007> bsc_subscr_conn_fsm.c:286 SUBSCR_CONN(msc0-conn4294967295_IMSI515020220004012)[0x558560323460]{INIT}: state_chg to WAIT_CC 20220226175416664 DLSCCP <0020> sccp_scoc.c:1662 Received CO:COAK for local reference 7 20220226175416664 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{CONN_PEND_OUT}: Received Event RCOC-CONNECT_CONFIRM.ind 20220226175416664 DLSCCP <0020> sccp_scoc.c:981 SCCP-SCOC(7)[0x55856030ca50]{CONN_PEND_OUT}: state_chg to ACTIVE 20220226175416664 DLSCCP <0020> sccp_user.c:175 Delivering N-CONNECT.confirm to SCCP User 'msc-0' 20220226175416664 DMSC <0007> osmo_bsc_sigtran.c:244 N-CONNECT.cnf(7, ) 20220226175416664 DMSC <0007> osmo_bsc_sigtran.c:247 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{WAIT_CC}: Received Event MO-CONNECT.cfm 20220226175416664 DMSC <0007> bsc_subscr_conn_fsm.c:354 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{WAIT_CC}: state_chg to ACTIVE 20220226175416664 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 7 20220226175416664 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event RCOC-DT1.ind 20220226175416664 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226175416664 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(7, 00 0b 2f 08 08 59 51 20 20 02 00 04 21 ) 20220226175416664 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x55856030c700]{CONN}: Received Event EV_N_CONNECT 20220226175416664 DMSC <0007> osmo_bsc_bssap.c:1153 Rx MSC DT1 BSSMAP COMMON ID 20220226175416664 DMSC <0007> osmo_bsc_bssap.c:1099 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event COMMON_ID.ind 20220226175416664 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 7 20220226175416664 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event RCOC-DT1.ind 20220226175416664 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226175416664 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(7, 01 03 26 09 01 23 01 00 07 91 44 77 58 10 06 50 00 17 20 06 d1 32 99 0c 00 00 22 20 62 71 45 51 23 07 f4 f2 9c 9e 76 9f 01 ) 20220226175416664 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x55856030c700]{CONN}: Received Event EV_N_CONNECT 20220226175416664 DMSC <0007> osmo_bsc_bssap.c:1208 Rx MSC DTAP: 01 03 26 09 01 23 01 00 07 91 44 77 58 10 06 50 00 17 20 06 d1 32 99 0c 00 00 22 20 62 71 45 51 23 07 f4 f2 9c 9e 76 9f 01 20220226175416664 DMSC <0007> osmo_bsc_bssap.c:1232 Rx MSC DTAP, SAPI: 3 CHAN: 0 20220226175416664 DMSC <0007> osmo_bsc_bssap.c:1249 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event MT_DTAP 20220226175416664 DRLL <0000> abis_rsl.c:833 (bts=0,trx=0,ts=0,ss=0) RSL RLL ESTABLISH REQ (link_id=0x03) 20220226175416757 DRSL <0003> abis_rsl.c:1082 (bts=0,trx=0,ts=0,ss=0): meas_rep_count++=1 meas_rep_last_seen_nr=0 20220226175416907 DRLL <0000> chan_alloc.c:240 (bts=0) channel load average is 0.20% 20220226175416907 DRLL <0000> chan_alloc.c:253 (bts=0) T3122 wait indicator set to 10 seconds 20220226175417227 DRSL <0003> abis_rsl.c:1082 (bts=0,trx=0,ts=0,ss=0): meas_rep_count++=2 meas_rep_last_seen_nr=1 20220226175417839 DMSC <0007> gsm_08_08.c:548 Tx MSC DTAP LINK_ID=0x03 20220226175417839 DMSC <0007> gsm_08_08.c:554 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event MO_DTAP 20220226175417839 DMSC <0007> osmo_bsc_sigtran.c:394 Tx MSC: DTAP 20220226175417839 DMSC <0007> osmo_bsc_sigtran.c:418 Sending connection (id=7) oriented data to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP (01 03 02 89 04 ) 20220226175417839 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-DATA.request) 20220226175417839 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event N-DATA.req 20220226175418075 DMSC <0007> gsm_08_08.c:548 Tx MSC DTAP LINK_ID=0x03 20220226175418075 DMSC <0007> gsm_08_08.c:554 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event MO_DTAP 20220226175418075 DMSC <0007> osmo_bsc_sigtran.c:394 Tx MSC: DTAP 20220226175418076 DMSC <0007> osmo_bsc_sigtran.c:418 Sending connection (id=7) oriented data to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP (01 03 09 89 01 06 02 00 41 02 00 00 ) 20220226175418076 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-DATA.request) 20220226175418076 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event N-DATA.req 20220226175418085 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 7 20220226175418085 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event RCOC-DT1.ind 20220226175418085 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(7, 01 03 02 09 04 ) 20220226175418085 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x55856030c700]{CONN}: Received Event EV_N_CONNECT 20220226175418085 DMSC <0007> osmo_bsc_bssap.c:1208 Rx MSC DTAP: 01 03 02 09 04 20220226175418085 DMSC <0007> osmo_bsc_bssap.c:1232 Rx MSC DTAP, SAPI: 3 CHAN: 0 20220226175418085 DMSC <0007> osmo_bsc_bssap.c:1249 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event MT_DTAP 20220226175418085 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 7 20220226175418085 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event RCOC-DT1.ind 20220226175418085 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(7, 00 04 20 04 01 09 ) 20220226175418085 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x55856030c700]{CONN}: Received Event EV_N_CONNECT 20220226175418085 DMSC <0007> osmo_bsc_bssap.c:1153 Rx MSC DT1 BSSMAP CLEAR COMMAND 20220226175418085 DMSC <0007> osmo_bsc_bssap.c:473 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: Received Event CLEAR_CMD 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:774 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{ACTIVE}: state_chg to CLEARING 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:775 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Releasing all lchans (if any) after BSSMAP Clear Command 20220226175418085 DMSC <0007> lchan_fsm.c:1458 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: lchan lchan(0-0-0-CCCH_SDCCH4-0)[0x55856030cee0] detaches from conn 20220226175418085 DRR <0002> gsm_04_08_rr.c:323 Sending Channel Release: Chan: Number: 0 Type: 1 RR-Cause: 0x0 'Normal event' 20220226175418085 DRSL <0003> abis_rsl.c:644 (bts=0,trx=0,ts=0,ss=0) DEACTivate SACCH CMD 20220226175418085 DRLL <0000> abis_rsl.c:857 (bts=0,trx=0,ts=0,ss=0) RSL RLL RELEASE REQ (link_id=0x03, reason=1) 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:390 Tx MSC: BSSMAP: CLEAR COMPLETE 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:418 Sending connection (id=7) oriented data to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP (00 01 21 ) 20220226175418085 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-DATA.request) 20220226175418085 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event N-DATA.req 20220226175418085 DLSCCP <0020> sccp_scoc.c:1662 Received CO:RELRE for local reference 7 20220226175418085 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: Received Event RCOC-RELEASED.ind 20220226175418085 DLSCCP <0020> sccp_user.c:175 Delivering N-DISCONNECT.indication to SCCP User 'msc-0' 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:274 N-DISCONNECT.ind(7, , cause=768) 20220226175418085 DMSC <0007> osmo_bsc_sigtran.c:281 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Received Event DISCONNET.ind 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:791 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Terminating (cause = OSMO_FSM_TERM_REGULAR) 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:862 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: FSM instance already terminating, not dispatching event LCLS_FAIL 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:866 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Releasing all lchans (if any) because this conn is terminating 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:845 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Putting bsc_subscr 20220226175418085 DMSC <0007> bsc_subscr_conn_fsm.c:791 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Freeing instance 20220226175418085 DMSC <0007> fsm.c:573 SUBSCR_CONN(msc0-conn7_IMSI515020220004012)[0x558560323460]{CLEARING}: Deallocated 20220226175418085 DLSCCP <0020> sccp_scoc.c:1070 SCCP-SCOC(7)[0x55856030ca50]{ACTIVE}: state_chg to IDLE 20220226175418085 DLSCCP <0020> sccp_scoc.c:517 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: Terminating (cause = OSMO_FSM_TERM_REQUEST) 20220226175418085 DLSCCP <0020> sccp_scoc.c:517 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: Freeing instance 20220226175418085 DLSCCP <0020> fsm.c:573 SCCP-SCOC(7)[0x55856030ca50]{IDLE}: Deallocated 20220226175419767 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226175424767 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226175424910 DRLL <0000> chan_alloc.c:240 (bts=0) channel load average is 3.03% 20220226175424910 DRLL <0000> chan_alloc.c:253 (bts=0) T3122 wait indicator set to 10 seconds ========= Phone that doesnt receive sms ========== 20220226173512464 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226173514434 DRLL <0000> chan_alloc.c:240 (bts=0) channel load average is 0.00% 20220226173514434 DRLL <0000> chan_alloc.c:253 (bts=0) T3122 wait indicator set to 10 seconds 20220226173517464 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226173519748 DLSCCP <0020> sccp_user.c:175 Delivering N-UNITDATA.indication to SCCP User 'msc-0' 20220226173519748 DMSC <0007> osmo_bsc_sigtran.c:231 N-UNITDATA.ind(00 16 52 08 08 59 51 20 11 27 23 70 04 09 04 38 2a bc 18 1a 03 05 03 f4 ) 20220226173519748 DMSC <0007> osmo_bsc_bssap.c:1259 Rx MSC UDT: 00 16 52 08 08 59 51 20 11 27 23 70 04 09 04 38 2a bc 18 1a 03 05 03 f4 20220226173519748 DMSC <0007> osmo_bsc_bssap.c:1116 Rx MSC UDT BSSMAP PAGING 20220226173519748 DMSC <0007> osmo_bsc_bssap.c:131 Paging request from MSC BTS: 0 IMSI: '515021172320740' TMSI: '0x382abc18/942324760' LAC: 0x3f4 20220226173522006 DRSL <0003> abis_rsl.c:1383 (bts=0) CHAN RQD: reason: answer to paging (ra=0x87, neci=0x01, chreq_reason=0x01) 20220226173522006 DRLL <0000> lchan_select.c:173 (bts=0) lchan_select_by_type(SDCCH) 20220226173522006 DRLL <0000> lchan_select.c:87 looking for lchan CCCH+SDCCH4: (bts=0,trx=0,ts=0,pchan=CCCH+SDCCH4,state=UNUSED) ss=0 is available 20220226173522006 DRSL <0003> abis_rsl.c:476 (bts=0,trx=0,ts=0,pchan=CCCH+SDCCH4,state=IN_USE) Tx RSL Channel Activate with act_type=INITIAL 20220226173522295 DMSC <0007> fsm.c:461 SUBSCR_CONN[0x56450d5e3f80]{INIT}: Allocated 20220226173522295 DMSC <0007> gsm_08_08.c:489 Tx MSC COMPL L3 20220226173522295 DRSL <0003> gsm_08_08.c:232 RR GSM48_MT_RR_PAG_RESP: TMSI-0x382ABC18 matches earlier Paging from msc 0 20220226173522295 DMSC <0007> osmo_bsc_sigtran.c:308 Initializing resources for new SCCP connection to MSC 0: RI=SSN_PC,PC=0.23.1,SSN=BSSAP... 20220226173522295 DMSC <0007> gsm_08_08.c:532 SUBSCR_CONN(msc0-conn4294967295_IMSI515021172320740)[0x56450d5e3f80]{INIT}: Received Event MO-CONNECT.req 20220226173522295 DMSC <0007> osmo_bsc_sigtran.c:350 Allocated new connection id: 5 20220226173522295 DMSC <0007> osmo_bsc_sigtran.c:354 Opening new SCCP connection (id=5) to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP 20220226173522295 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-CONNECT.request) 20220226173522295 DLSCCP <0020> fsm.c:461 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: Allocated 20220226173522295 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: Received Event N-CONNECT.req 20220226173522295 DLSCCP <0020> sccp_scoc.c:830 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: state_chg to CONN_PEND_OUT 20220226173522295 DMSC <0007> bsc_subscr_conn_fsm.c:286 SUBSCR_CONN(msc0-conn4294967295_IMSI515021172320740)[0x56450d5e3f80]{INIT}: state_chg to WAIT_CC 20220226173522296 DLSCCP <0020> sccp_scoc.c:1662 Received CO:COAK for local reference 5 20220226173522296 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(5)[0x56450d5e2160]{CONN_PEND_OUT}: Received Event RCOC-CONNECT_CONFIRM.ind 20220226173522296 DLSCCP <0020> sccp_scoc.c:981 SCCP-SCOC(5)[0x56450d5e2160]{CONN_PEND_OUT}: state_chg to ACTIVE 20220226173522296 DLSCCP <0020> sccp_user.c:175 Delivering N-CONNECT.confirm to SCCP User 'msc-0' 20220226173522296 DMSC <0007> osmo_bsc_sigtran.c:244 N-CONNECT.cnf(5, ) 20220226173522296 DMSC <0007> osmo_bsc_sigtran.c:247 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{WAIT_CC}: Received Event MO-CONNECT.cfm 20220226173522296 DMSC <0007> bsc_subscr_conn_fsm.c:354 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{WAIT_CC}: state_chg to ACTIVE 20220226173522296 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 5 20220226173522296 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event RCOC-DT1.ind 20220226173522296 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226173522296 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(5, 00 0b 2f 08 08 59 51 20 11 27 23 70 04 ) 20220226173522296 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x56450d5d3700]{CONN}: Received Event EV_N_CONNECT 20220226173522296 DMSC <0007> osmo_bsc_bssap.c:1153 Rx MSC DT1 BSSMAP COMMON ID 20220226173522296 DMSC <0007> osmo_bsc_bssap.c:1099 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{ACTIVE}: Received Event COMMON_ID.ind 20220226173522296 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 5 20220226173522296 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event RCOC-DT1.ind 20220226173522296 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226173522296 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(5, 01 03 28 09 01 25 01 00 07 91 44 77 58 10 06 50 00 19 20 0c 91 36 39 71 82 34 93 00 00 22 20 62 71 53 91 23 06 f4 f2 9c 0e 92 01 ) 20220226173522296 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x56450d5d3700]{CONN}: Received Event EV_N_CONNECT 20220226173522296 DMSC <0007> osmo_bsc_bssap.c:1208 Rx MSC DTAP: 01 03 28 09 01 25 01 00 07 91 44 77 58 10 06 50 00 19 20 0c 91 36 39 71 82 34 93 00 00 22 20 62 71 53 91 23 06 f4 f2 9c 0e 92 01 20220226173522296 DMSC <0007> osmo_bsc_bssap.c:1232 Rx MSC DTAP, SAPI: 3 CHAN: 0 20220226173522296 DMSC <0007> osmo_bsc_bssap.c:1249 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{ACTIVE}: Received Event MT_DTAP 20220226173522296 DRLL <0000> abis_rsl.c:833 (bts=0,trx=0,ts=0,ss=0) RSL RLL ESTABLISH REQ (link_id=0x03) 20220226173522439 DRLL <0000> chan_alloc.c:240 (bts=0) channel load average is 0.20% 20220226173522439 DRLL <0000> chan_alloc.c:253 (bts=0) T3122 wait indicator set to 10 seconds 20220226173522464 DNM <0004> abis_nm.c:345 BTS 0 reported connected PCU version 0.8.0.178-b75c2 20220226173522766 DMSC <0007> gsm_08_08.c:71 Tx MSC SAPI N REJECT DLCI=0x03 20220226173522766 DMSC <0007> gsm_08_08.c:74 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{ACTIVE}: Received Event TX_SCCP 20220226173522766 DMSC <0007> osmo_bsc_sigtran.c:390 Tx MSC: BSSMAP: SAPI N REJECT 20220226173522766 DMSC <0007> osmo_bsc_sigtran.c:418 Sending connection (id=5) oriented data to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP (00 06 25 18 03 04 01 25 ) 20220226173522766 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-DATA.request) 20220226173522766 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event N-DATA.req 20220226173522768 DLSCCP <0020> sccp_scoc.c:1662 Received CO:CODT for local reference 5 20220226173522768 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event RCOC-DT1.ind 20220226173522768 DLSCCP <0020> sccp_user.c:175 Delivering N-DATA.indication to SCCP User 'msc-0' 20220226173522768 DMSC <0007> osmo_bsc_sigtran.c:261 N-DATA.ind(5, 00 04 20 04 01 09 ) 20220226173522768 DMSC <0007> a_reset.c:227 A-RESET(msc-0)[0x56450d5d3700]{CONN}: Received Event EV_N_CONNECT 20220226173522768 DMSC <0007> osmo_bsc_bssap.c:1153 Rx MSC DT1 BSSMAP CLEAR COMMAND 20220226173522768 DMSC <0007> osmo_bsc_bssap.c:473 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{ACTIVE}: Received Event CLEAR_CMD 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:774 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{ACTIVE}: state_chg to CLEARING 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:775 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Releasing all lchans (if any) after BSSMAP Clear Command 20220226173522768 DMSC <0007> lchan_fsm.c:1458 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: lchan lchan(0-0-0-CCCH_SDCCH4-0)[0x56450d5e4240] detaches from conn 20220226173522768 DRR <0002> gsm_04_08_rr.c:323 Sending Channel Release: Chan: Number: 0 Type: 1 RR-Cause: 0x0 'Normal event' 20220226173522768 DRSL <0003> abis_rsl.c:644 (bts=0,trx=0,ts=0,ss=0) DEACTivate SACCH CMD 20220226173522768 DMSC <0007> osmo_bsc_sigtran.c:390 Tx MSC: BSSMAP: CLEAR COMPLETE 20220226173522768 DMSC <0007> osmo_bsc_sigtran.c:418 Sending connection (id=5) oriented data to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP (00 01 21 ) 20220226173522768 DLSCCP <0020> sccp_scoc.c:1729 Received SCCP User Primitive (N-DATA.request) 20220226173522768 DLSCCP <0020> sccp_scoc.c:1769 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event N-DATA.req 20220226173522768 DLSCCP <0020> sccp_scoc.c:1662 Received CO:RELRE for local reference 5 20220226173522768 DLSCCP <0020> sccp_scoc.c:1695 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: Received Event RCOC-RELEASED.ind 20220226173522768 DLSCCP <0020> sccp_user.c:175 Delivering N-DISCONNECT.indication to SCCP User 'msc-0' 20220226173522768 DMSC <0007> osmo_bsc_sigtran.c:274 N-DISCONNECT.ind(5, , cause=768) 20220226173522768 DMSC <0007> osmo_bsc_sigtran.c:281 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Received Event DISCONNET.ind 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:791 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Terminating (cause = OSMO_FSM_TERM_REGULAR) 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:862 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: FSM instance already terminating, not dispatching event LCLS_FAIL 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:866 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Releasing all lchans (if any) because this conn is terminating 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:845 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Putting bsc_subscr 20220226173522768 DMSC <0007> bsc_subscr_conn_fsm.c:791 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Freeing instance 20220226173522768 DMSC <0007> fsm.c:573 SUBSCR_CONN(msc0-conn5_IMSI515021172320740)[0x56450d5e3f80]{CLEARING}: Deallocated 20220226173522768 DLSCCP <0020> sccp_scoc.c:1070 SCCP-SCOC(5)[0x56450d5e2160]{ACTIVE}: state_chg to IDLE 20220226173522768 DLSCCP <0020> sccp_scoc.c:517 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: Terminating (cause = OSMO_FSM_TERM_REQUEST) 20220226173522768 DLSCCP <0020> sccp_scoc.c:517 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: Freeing instance 20220226173522768 DLSCCP <0020> fsm.c:573 SCCP-SCOC(5)[0x56450d5e2160]{IDLE}: Deallocated ======== Osmo-bts-trx config ! ! OsmoBTS () configuration saved from vty !! ! log stderr logging color 1 logging timestamp 0 logging level rsl notice logging level oml notice logging level rll notice logging level rr notice logging level meas error logging level pag error logging level l1c error logging level l1p error logging level dsp error logging level abis error logging level loop debug ! line vty no login ! phy 0 instance 0 !COMMENT HERE FOR DEFAULT JOJO osmotrx rx-gain 50 osmotrx tx-attenuation 0 !osmotrx rx-gain 10 !osmotrx tx-attenuation oml !osmotrx maxdly 20 osmotrx ip local 127.0.0.1 osmotrx ip remote 127.0.0.1 bts 0 band 900 ipa unit-id 1012 0 oml remote-ip 127.0.0.1 gsmtap-sapi ccch gsmtap-sapi pdtch !ADDED FOR TEST JOJO gsmtap-sapi bcch gsmtap-sapi rach gsmtap-sapi agch gsmtap-sapi sdcch gsmtap-sapi sacch uplink-power-target -110 trx 0 !ms-power-control osmo !power-ramp max-initial 0 dBm !power-ramp step-size 2000 dB !power-ramp step-interval 10 phy 0 instance 0 ========= Osmo-bsc config ========= ! Configuration rendered by osmo-gsm-tester log stderr logging filter all 1 logging color 1 logging print category 1 logging print extended-timestamp 1 logging level all debug line vty no login bind 127.0.0.1 ctrl bind 127.0.0.1 e1_input e1_line 0 driver ipa ipa bind 127.0.0.1 network network country code 515 mobile network code 02 encryption a5 0 neci 1 handover 0 handover window rxlev averaging 10 handover window rxqual averaging 1 handover window rxlev neighbor averaging 10 handover power budget interval 6 handover power budget hysteresis 4 handover maximum distance 9999 allow-unusable-timeslots bts 0 type sysmobts band 900 cell_identity 1012 location_area_code 1012 training_sequence_code 1 base_station_id_code 1 channel-description attach 0 !ms max power 40 cell reselection hysteresis 4 rxlev access min 0 channel allocator ascending rach tx integer 9 rach max transmission 7 ip.access unit_id 1012 0 oml ip.access stream_id 255 line 0 gprs mode none no force-combined-si trx 0 rf_locked 0 arfcn 27 !nominal power 40 nominal power 80 ! to use full TRX power, set max_power_red 0 max_power_red 0 rsl e1 tei 0 timeslot 0 phys_chan_config CCCH+SDCCH4 hopping enabled 0 timeslot 1 phys_chan_config SDCCH8 hopping enabled 0 timeslot 2 phys_chan_config TCH/F hopping enabled 0 timeslot 3 phys_chan_config TCH/F hopping enabled 0 timeslot 4 phys_chan_config TCH/F hopping enabled 0 timeslot 5 phys_chan_config TCH/F hopping enabled 0 timeslot 6 phys_chan_config TCH/F hopping enabled 0 timeslot 7 phys_chan_config PDCH hopping enabled 0 msc 0 !ip.access rtp-base 25000 no bsc-welcome-text no bsc-msc-lost-text no bsc-grace-text type normal allow-emergency allow !codec-list fr1 !amr-config 12_2k forbidden !amr-config 10_2k forbidden !amr-config 7_95k forbidden !amr-config 7_40k forbidden !amr-config 6_70k forbidden !amr-config 5_90k forbidden !amr-config 5_15k forbidden !amr-config 4_75k forbidden mgw remote-ip 127.0.0.1 mgw remote-port 2427 !mgw endpoint-range 1 31 mgw local-ip 127.0.0.1 bsc mid-call-timeout 0 ========== Osmo-msc config ========== ! ! OsmoMSC configuration saved from vty ! log stderr logging filter all 1 logging color 0 logging print category 1 logging timestamp 1 logging level all everything logging level rll notice logging level cc notice logging level mm notice logging level mm debug logging level rr notice logging level pag notice logging level msc notice logging level mgcp notice logging level ho notice logging level ref notice logging level ctrl notice logging level lglobal notice logging level llapd notice logging level linp notice logging level lmux notice logging level lmi notice logging level lmib notice logging level lsms notice logging level lctrl notice logging level lgtp notice logging level lstats notice logging level lgsup notice logging level loap notice logging level lss7 notice logging level lsccp notice logging level lsua notice logging level lm3ua notice logging level lmgcp notice logging level all debug line vty no login bind 127.0.0.1 ! network network country code 515 mobile network code 02 short name GLOBE long name GLOBE encryption a5 0 rrlp mode none mm info 1 timezone 8 0 msc mgw remote-ip 127.0.0.1 mgw remote-port 2427 mgw local-ip 127.0.0.1 !mgw endpoint-range 1 31 !mgw bts-base 8000 assign-tmsi cs7-instance-a 0 check-imei-rqd early !timer vlr T3212 1 ctrl bind 127.0.0.1 mncc-int default-codec tch-f fr default-codec tch-h hr hlr remote-ip 127.0.0.1 smpp local-tcp-port 2775 policy accept-all smpp-first esme bhat password bhat default-route

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Splitting out M3UA and MTP3 out of Open BSC into a separate library
by Arran Cudbard-Bell 15 Dec '25

15 Dec '25

Hi, Developing a module for FreeRADIUS to support EAP-SIM and EAP-AKA authentication against a HLR. The HLR we were targeting only supported a SCTP/M3UA/SCCP/TCAP/MAP stack, so we couldn't use SUA. Ripping the M3UA/MTP3 code out of OpenBSC worked surprisingly well. We ended up running the event loop in a separate thread to work around the threading issues. Unfortunately the HLR implements the ANSI variant of everything, whereas OpenBSC and supporting libraries seem to have been written to be compatible with the ITU standards. ...but the differences are fairly minor at MTP3 and SCCP layers, and i've started work on a patchset for libosmo-sccp. https://gerrit.osmocom.org/#/c/73/ Anyway, trying to gauge interest in splitting those layers out of Open BSC into a separate library, would be happy to take on M2UA as well for consistency. It would almost certainly get more projects using the code. There's very little out there even in Perl land for working with SS7. Thanks, -Arran Arran Cudbard-Bell <a.cudbardb(a)freeradius.org> FreeRADIUS Development Team FD31 3077 42EC 7FCD 32FE 5EE2 56CF 27F9 30A8 CAA2

8 8

Front and back sides of an MSC
by Mychaela Falconia 09 Dec '25

09 Dec '25

Hello Osmocom community, I have a question about terminology that is not really specific to Osmocom, but is specific to GSM/3G/etc cellular industry, or whatever is left of it. An MSC in a GSM or 3G or any other circuit-switched cellular network has two sides: one side facing the RAN (A interface in GSM, IuCS in 3G), the other side facing PSTN or ISDN or BICC or SIP-I or whatever the fixed telephone network may be. My question: is there a general industry-wide agreement as to which side should be called the front and which should be called the back? To me it seems intuitive to refer to the A/IuCS side of an MSC as the front and the PSTN/ISDN/BICC/SIP-I side of the same MSC as the back. However, I am just one person, and I have no idea whether or not my view is intuitive to others. And it would even worse if the opposite convention happens to be widely used... Hence I am asking this community, in the hope that someone with more industry experience would know how telco network engineers casually refer to RAN-facing and fixed-network-facing sides of an MSC. For a long time I had the idea of building ThemWi MSC as a modular system (multiple processes talking to each other via sockets) with a stripped-down OsmoMSC derivative as the "central" component, and with a radically different placement of MSC-MGW. However, as I started working on more detailed design, I realized a major flaw in my originally envisioned architecture: my original approach to MSC-MGW would break TFO for AMR, specifically the dialogue between TFO-aware BTS and the TRAU equivalent in the MGW. I am now spinning a new architecture in my head, one which tentatively includes two dissimilar MGWs in the MSC. If my front vs back terminology is valid, then the front MGW (talking to AoIP user plane) would perform speech transcoding but become a transparent pass-through for CSD (basically a software-only, IP-based equivalent of a hardware TCSM colocated at the MSC site), while the back MGW would be a transparent pass-through for speech calls, but turn into a complex IWF for CSD. This tentative architecture exactly matches the placement of speech transcoding and CSD IWF functions in traditional hardware MSCs of TDM-based, before-AoIP world. But I need to know if I should keep these front and back terms, or swap them the other way around. M~

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OpenBSC November 2025