August 2022 - baseband-devel - lists.osmocom.org

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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Re: New attack ?
by Mychaela Falconia 06 Jun '23

06 Jun '23

Bastien Baranoff wrote: > Hello all, the attack : you generate the rainbow tables for each possibles ki > with a given rand set, send this rand (which is not random ;) the phone > respond with sres you make the operation for 3 or 4 rand and meaningly > decrease the possibility of ki. Do you think it is realisable ? Someone please correct me if I'm wrong on this detail, but it is my understanding that no mainstream commercial operator today (outside of personal enthusiast tinkerers in Osmocom and similar communities) issues native 2G SIM cards any more - instead all of their current SIM cards are actually USIM/ISIM, and if GSM 11.11 SIM operation is supported at all, it is only provided as a backward compatibility mode. I reason that these "modern" SIMs must be using Milenage in their native 3G/4G mode, thus their secret key material is not classic Ki, but K/Ki (128 bits) plus OPc (another 128 bits), for a total of 256 bits of secret key material. What happens when these "modern" SIMs are accessed via GSM 11.11 SIM protocol, or when 2G authentication is requested in a USIM session? I find it doubtful that they switch to COMP128 (any version) in this mode, instead I reason that they use 2G mode of Milenage, which still uses both K/Ki and OPc - thus the secret key material used even for 2G Kc and SRES generation from RAND is still 256 bits rather than 128. Again, someone please correct me if my reasoning is wrong here. M~

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Re: About 3g5 hardware
by Bastien Baranoff 07 Aug '22

07 Aug '22

Hello if I remember i have tested to telnet 192.168.0.1 8090 or if I broadcast DHCP from my PC I have 192.168.0.142 but in both cases i have connection refused :( you mean that if I buy sysmocell i will be able to flash FW on my nano3G will check if I can have serial. Thank you for your response I will keep the community in touch if I can go further. I will only be able to make new tests in 10 days... :( Le dim. 7 août 2022 à 16:09, Neels Hofmeyr <nhofmeyr(a)sysmocom.de> a écrit : > I dimly remember that the nano3G have both serial console contacts you can > solder onto, as well as an exploitable DHCP client (what i heard is that > the > DHCP client is a bash script that fails to properly escape the host name > given > to the DHCP client). With that you might be able to gain ssh access. Even > then > you may not have much of a chance to get it to run, depending on the > installed > firmware. > > A factoid is that a nano3G obtained from sysmocom.de will work with > osmo-hnbgw. > Not sure if it is still in the shop... Some of them have also been given > away > free of charge, to non-commercial users: research / hacker spaces. So if I > needed one to play with, I guess I would ask sysmocom indicating my > intended > use, or ask some of the people that got one from Accelerate3g5 -- in case > there's someone no longer using their nano3G: > https://osmocom.org/projects/cellular-infrastructure/wiki/Accelerate3g5 > > HTH, > > ~N >

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About 3g5 hardware
by Bastien Baranoff 07 Aug '22

07 Aug '22

Hello @osmocom i wonder something. I have bought IP. accès NANO 3 G S8 Modèle # 237BA UMTS Band 2/5 (800 Mhz) will i have a chance to make it work with accelerate 3g5 software thanks, Bastien Baranoff

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