November 2020 - baseband-devel

SMS not received in mobile - Virtual layer1 (osmo-nitb + osmo-bts + osmocom-bb/mobile)
by Sebastian Stumpf 05 Jun '26

05 Jun '26

Hi, Some of my sent SMS are not received by my mobile and I try to figure out if this is a problem with my virtual layer 1, configuration or something in the layers 2+. I use: osmo-nitb: 1 subscriber in hlr (id 1, ext 017519191919) osmo-bts: virt-phy, arfcn 666, TS0=CCCH+SDCCH4, TS1=SDCCH8 MS layer23 app mobile: is the subscriber from osmo-nitb MS layer1 virt-phy: virtual gsmtap layer between bts and mobile I want: Send a sms to subscriber 017519191919. osmo-nitb VTY: OpenBSC# subscriber id 1 sms sender id 1 send Test I have 2 outcomes, first one is the failure. See https://www.dropbox.com/s/eunpfioq518t09a/mobile--ms-virt--bts-virt--bsc-ni… for the pcap. Do not wonder about the duplicated gsmtap messages from mobile, the ones to ip 225.0.0.1 are over virt-phy layer, the ones to localhost from the gsmtap logging option from mobile. Filter them out via "gsmtap && (ip.dst != 127.0.0.1)". 602-613: RR channel establishment with RA and IA as reaction to paging in 590 627,631: SABM from BTS to establish async balanced mode on SAPI3 (SMS) and the ACK from MS 656,684,699: I-Data frames on SAPI3 containing the sms 660,688,703: ReceiveReady's from MS (That ACK all I-frames before N(R)-1 as far as I understood) For me, that looks good and I really do not understand why the MS will not answer with the CP-ACK/RP-ACK after receiving the SMS Data in 699. The LAPDM link will stay up for some more time and be used by the network for retransmission of the sms (1149), but MS will never react to it on the SMS layer (CP-ACK, RP-ACK). Here is the console log for the mobile (https://www.dropbox.com/s/6gug5cd4up5qv7y/mobile--ms-virt--bts-virt--bsc-ni…) The paging is answered in line 378: Fri Mar 10 10:42:06 2017 DLLAPD <0012> lapd_core.c:793 SABM(E) received in state LAPD_STATE_IDLE Second outcome is a successfully sent sms from network to ms. See https://www.dropbox.com/s/ghdn7pc0j4vifbe/mobile--ms-virt--bts-virt--bsc-ni… for the pcap. What is different here? There is no paging, but the sms is sent within the dedicated channel used for the location update initiated by the phone started up. Why there is another outcome, I don't know. 169-181: RR channel establishment with RA and IA as part of mibiles startup routine to make location update 188,416: Location udpdate procedure on SAPI0 230,234: SABM from BTS to establish async balanced mode on SAPI3 (SMS) and the ACK from MS 396,444: I-Data frames on SAPI3 containing the sms 400,449: RR's from MS 450: CP-ACK for BTS 482,499: RP-ACK I-Frames for Network (osmo-nitb) Again, the console log of the mobile (https://www.dropbox.com/s/cujsn40d43g6wxk/mobile--ms-virt--bts-virt--bsc-ni…) The SABM on SAPI3 on downlink is received in line 206: Fri Mar 10 11:06:13 2017 DLLAPD <0012> lapd_core.c:793 SABM(E) received in state LAPD_STATE_IDLE The signaling looks quite similar in both cases, but one time the mobiles sms handler responds to CP-DATA msg containing the SMS, the other time not. Can someone find an error in the signaling I did not see? Is there a known Bug? To be honest, I last merged my branch with master some time ago (~ Jan 18 2017) and thus did not update osmo-nitb and the libraries since then to avoid compatibility problems. Have there been recent changes that could cause that behavior? Thank you and Kind Regards, Sebastian

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Engagetted !
by Sébastien Lorquet 14 Oct '25

14 Oct '25

http://www.engadget.com/2010/12/29/researchers-eavesdrop-on-encrypted-gsm-c… Congrats!

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"Bad signalling message, sign_link returned error: Operation not permitted" - during voice call
by Mario Lucas 03 Dec '20

03 Dec '20

Dear team, I did set up GSM network with SDR (LimeSDRmini). SMS are ok. However when try to make voice call got following message on osmo-bsc terminal: <0003> abis_rsl.c:1372 (bts=0) CHAN RQD: reason: call re-establishment (ra=0x41, neci=0x01, chreq_reason=0x02) <0007> osmo_bsc_sigtran.c:305 Initializing resources for new SIGTRAN connection to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP... <0007> osmo_bsc_sigtran.c:351 Opening new SIGTRAN connection (id=31) to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP <0003> abis_rsl.c:1372 (bts=0) CHAN RQD: reason: answer to paging (ra=0x9b, neci=0x01, chreq_reason=0x01) <0007> osmo_bsc_sigtran.c:305 Initializing resources for new SIGTRAN connection to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP... <0007> osmo_bsc_sigtran.c:351 Opening new SIGTRAN connection (id=32) to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP <0004> abis_nm.c:344 BTS 0 reported connected PCU version 0.8.0 <0016> input/ipaccess.c:411 Bad signalling message, sign_link returned error: Operation not permitted. <0016> input/ipaccess.c:411 Bad signalling message, sign_link returned error: Operation not permitted. WHat is this bad signalling message operation not permitted? -- Mario Lucas

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Osmocom C files syntax understanding
by Mario Lucas 25 Nov '20

25 Nov '20

Dear baseband-developers team, Would you be so kind to advise me on the following: I desire (dramatically want very much) to learn / understand Osmocom projects. I am a beginner in programming and i try to understand / learn C files that the project is build of. As an example i tried to learn / understand for example an Osmocom message buffer — msgb.h file. But immediately faced some syntax difficulties: This is the extract of msgb.h file: struct msgb { struct llist_head list; /*!< \brief linked list header */ /* Part of which TRX logical channel we were received / transmitted */ /* FIXME: move them into the control buffer */ union { void *dst; /*!< \brief reference of origin/destination */ struct gsm_bts_trx *trx; }; As it can be seen a structure «msgb» has as one of its components another structure — «gsm_bts_trx» But in whole Osmocom BB project files i could not find definition / description of struct «gsm_bts_trx». Would you kindly advise me please how to see which components / constituents / elements are in this gsm_bts_trx structure? From which components is struct gsm_bts_trx build of? Thank you so much for your kind advise. -- Mario Lucas

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Dropped packets by HW.... Dumping Stale bursts
by Mario Lucas 25 Nov '20

25 Nov '20

Dear all, I am using LimeSDRmini to run osmo-bts… During operation from time-to time (and sometimes quite frequently) following messages pop-up in terminal: «Dropped packets by HW!» and «Dumping Stale bursts...» I guess my LimeSDRmini is dropping some packets. LimeSDRmini configuration is: Firmware 6, Hardware 3, Protocol1, Gateware 1.3. Would you advise — may be there is more or less stable firmware version that to some extent is stable while working with Osmo-bts ? Thanks -- Mario Lucas

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PCU socket not connected, dropping message
by Mario Lucas 23 Nov '20

23 Nov '20

Dear baseband developers team, I built home gsm network with Osmo-stp-msc-hlr-bsc-bts, osmo-trx limeSDR. I managed and registered phones. I did send sms between each other. However when i decided to make a call — i noticed following message in terminal: «PCU socket not connected, dropping message». I searched on Osmocom web site and it is said that pcu socket is involved in GPRS things (i.e. in internet). Therefore why does such message appears when i try to make simple call between two mobiles — it has nothing to do with GPRS… And what would you advise me how to resolve this ? P.S. initially when i was about to start osmo-bts-trx i got message «PCU L1 socket failed» and i just renamed the pcu_bts file to some other name and osmo-bts-trx started. Thank you so much for your kind reply. Best regards -- Mario Lucas

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fixeria trx.highram.bin stuck
by Mario Lucas 11 Nov '20

11 Nov '20

Dear all, Pls help me with the following issue: I want to run a transceiver having motorola c115… i follow the procedure described in CalypsoBTS page : http://osmocom.org/projects/baseband/wiki/CalypsoBTS without chainloader i get: /home/ubuntu# /home/ubuntu/trx/src/host/osmocon/./osmocon -m c123xor -p /dev/ttyUSB0 /home/ubuntu/trx/src/target/firmware/board/compal_e88/trx.highram.bin got 7 bytes from modem, data looks like: 66 74 6d 74 6f 6f 6c ftmtool Received FTMTOOL from phone, ramloader has aborted got 1 bytes from modem, data looks like: 65 e got 1 bytes from modem, data looks like: c1 . got 1 bytes from modem, data looks like: 66 f and with chainloader i get: /home/ubuntu# /home/ubuntu/trx/src/host/osmocon/./osmocon -m c123xor -p /dev/ttyUSB0 -c /home/ubuntu/trx/src/target/firmware/board/compal_e88/trx.highram.bin got 2 bytes from modem, data looks like: 04 81 .. got 5 bytes from modem, data looks like: 1b f6 02 00 41 ....A got 1 bytes from modem, data looks like: 01 . got 1 bytes from modem, data looks like: 40 @ Received PROMPT1 from phone, responding with CMD read_file(chainloader): file_size=32, hdr_len=4, dnload_len=39 got 1 bytes from modem, data looks like: 00 . it seems with chainloader it is trying to do more but still stuck…. pls help…. Mario -- Mario Lucas

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