- OpenBSC - lists.osmocom.org

"lai_and_lac"
by Neels Hofmeyr 26 Mar '18

26 Mar '18

Hi stsp, I noticed in the recent gsm0808_cell_id_list2 a review item slipped by: A "LAI" is by definition a PLMN (MCC+MNC) plus a LAC. So saying "LAI and LAC" is like saying "My family and my brother". So maybe we want to rename the "lai_and_lac" member of struct gsm0808_cell_id_list2 before it gets tagged for release. Just "lai" would be accurate, as its type (struct osmo_location_area_id) suggests. ~N

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OSMO-BTS-TRX: Cannot send payload with invalid length! (expecting 15, received 14)
by Ron 23 Mar '18

23 Mar '18

Hi Support, In Half Rate configuration of OSMO-BSC, is there a way to used ETSI TS 101 318 standard for its RTP Payload Format? As per testing, the RTP Payload format used by OSMO is RFC5993. Can this be configured in OSMO-BSC or OSMO-BTS-TRX? Or the configuration of this is hard coded? Logs from OSMO-BTS-TRX: [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) [0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0015> trau/osmo_ortp.c:0 Receiving packet with unknown payload type 111.[0;m<0006> scheduler_trx.c:543 Cannot send payload with invalid length! (expecting 15, received 14) TIA! Best Regard, Ron Menez ron.menez(a)entropysolution.com<mailto:ron.menez@entropysolution.com>

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MSC subscriber conn FSM issues
by Neels Hofmeyr 19 Mar '18

19 Mar '18

In recent weeks, many of you have encountered and worked at failures of OsmoMSC's subscriber conn FSM / the conn itself to handle corner cases and/or cleanly handle error situations. I have plans for that FSM to be reviewed, adding probably two more states to it, a) to properly handle the early startup and b) gracefully release in all situations; and to probably more closely glue the conn struct to the FSM. My humble suggestion is to wait for me to review it and not spend more time on it until that is through. I wrote the FSM initially, and it makes sense that I clarify its structuring before all of you need to learn its current quirks. I hope it won't take too long, just need to sort the priorities of this fix versus the other tasks I have... ~N

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changes in osmo-ttcn3-hacks (logging, external dependencies)
by Harald Welte 19 Mar '18

19 Mar '18

Dear all, I've changed some details related to logging: * we now generate per-testcase merged TITAN log files with the same name prefix as the pcap files (Module.Testcase.{pcap,merged}) and remove the hundreds of per-component log files generated by the parallel executor after merging them. * the console log verbosity has been incresed to include all output from explicit "log()" statements. This is particularly useful when running the tests interactively. Unrelated to the above, I removed our own copies of the MTP3/M3UA/SCCP emulation and replaced it with the proper upstream git repositories under 'deps' like most other external modules. This means that you will need to * update your 'deps' (make deps-update) * remove/re-generate your symlinks (gen_links.sh) from e.g. 'bsc' or 'msc' * re-generate the makefile subsequently It may be that the make file dependency logic doesn't pick this up automatically, so if you see some strange build errors, it may be a good idea to clean your local work tree. 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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BSC_Tests.ttcn now needs TITAN 6.3.1 to build
by Harald Welte 16 Mar '18

16 Mar '18

Dear all, as I explained in https://osmocom.org/issues/3070 for some reason BSC_Tests.ttcn fails to work under TITAN 6.1.0 anymore. Rather than debugging old TITAN versions, I decided to update to the latest stable release (6.3.1) in the debian-stretch-titan container that we use on jenkins. Please keep this in mind when running tests locally: * for containerized setups, switch to latest docker-playground master and re-build the debain-stretch-titan container before building any of the ttcn3-*-test containers based on it * if you build+run the ttcn-3 code on your native machine/distro, pleaes switch to TITAN 6.3.1. If you run Debian 9, you can use the package from network:osmocom:latest 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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docker-playground to gerrit?
by Neels Hofmeyr 16 Mar '18

16 Mar '18

Do I have permission to move the docker-playground.git to gerrit? I have a bunch of patches already in my various branches. I could just push them onto master, but I guess some code review would be good? Should we also add a gerrit job that tests the changes? Kind of hard to make a failure decision though while when some tests are normally failing, like they still are. ~N

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ttcn3: BSSGP_Types.ttcn MCC-MNC
by Neels Hofmeyr 16 Mar '18

16 Mar '18

In the file BSSGP_Types.ttcn -> ../deps/titan.ProtocolModules.BSSGP_v13.0.0/src/BSSGP_Types.ttcn I notice many PLMN definitions like type record PLMN_Identity { OCT1 iEI, BIT1 ext, LIN2_2a lengthIndicator, HEX1 mccDigit1, HEX1 mccDigit2, HEX1 mccDigit3, HEX1 mncDigit3, HEX1 mncDigit1, HEX1 mncDigit2 } which at first glance looks like they got the MCC-MNC digits ordered wrongly. It is correct as long as the less significant nibble comes first. And using these in PLMN tests gives the expected results. Now I assume that the HEX1 means that it's a nibble, where the less significant nibble comes first, sort of a "network nibble order" if that makes any sense. It is weird, though -- do we need to compose hex strings "reversed" as well?? ~N

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re failing ttcn BTS_Tests / pcuif_proto.h version bump
by Neels Hofmeyr 13 Mar '18

13 Mar '18

I have a trivial patch adding the new data item to the PCUIF_Types.ttcn (see branch neels/pcu in osmo-ttcn3-hacks.git), but I can't get the TC_pcu_act_req() to pass. I have trouble understanding where in that the PCUIF version would take effect, I can't find any place where it is populated. That would need a bump to version 9. Maybe that's not needed at all. All I get is 21:13:27.702570 mtc BTS_Tests.ttcn:1883 setverdict(fail): none -> fail reason: "Timeout waiting for PCU R TS.req", new component reason: "Timeout waiting for PCU RTS.req" and I can't figure out why. It doesn't seem related to the pcuif_proto.h anyway. ~N

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Hardware for 3G
by Bruckner Jan (ETAS-SEC/ECT-Mu) 13 Mar '18

13 Mar '18

Hi all, I'm interested in upgrading my 2G setup to also support 3G. My current setup is: USRP N210, osmo-trx, osmo-bts-trx, osmo-nitb, osmo-pcu, osmo-sgsn, osmo-ggsn. On the software side I understand I'd have to migrate from osmo-nitb to the new split components and add the 3G components. Regarding the hardware it seems most people are using the ip.access nano3G femtocell. Is this the same one that's included in the sysmocom 3.5G starter kit? Are there any alternatives I'm not aware of other than using non-Osmocom projects? Thanks, Jan

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GSM 04.08 L2 pseudo length in ACCH System Information messages
by Vadim Yanitskiy 12 Mar '18

12 Mar '18

Hi everyone, I few days ago, during some usual R&D process, I noticed the following messages, appearing in the log output of OsmocomBB/mobile application: "ACCH message type 0xXX unknown." The network, a phone was connected to, was may own and based on more or less recent versions of OsmoNiTB, OsmoBTS, and OsmoTRX. Despite I used to see such messages before, I didn't pay too much attention. But this time I've decided to figure out, what's wrong there... The source of such messages is the gsm48_rr.c / gsm48_rr_rx_acch(): static int gsm48_rr_rx_acch(struct osmocom_ms *ms, struct msgb *msg) { // ... struct gsm48_system_information_type_header *sih = msgb_l3(msg); // ... switch (sih->system_information) { case GSM48_MT_RR_SYSINFO_5: return gsm48_rr_rx_sysinfo5(ms, msg); case GSM48_MT_RR_SYSINFO_5bis: return gsm48_rr_rx_sysinfo5bis(ms, msg); case GSM48_MT_RR_SYSINFO_5ter: return gsm48_rr_rx_sysinfo5ter(ms, msg); case GSM48_MT_RR_SYSINFO_6: return gsm48_rr_rx_sysinfo6(ms, msg); default: LOGP(DRR, LOGL_NOTICE, "ACCH message type 0x%02x unknown.\n", sih->system_information); return -EINVAL; } } To get I bit more details, I modified this function to print the whole L3 payload, and got some interesting results. As it turned out, the payloads were shifted one byte left - there was no 'l2_plen', which is assumed by: /* Section 9.1.3x System information Type header */ struct gsm48_system_information_type_header { uint8_t l2_plen; uint8_t rr_protocol_discriminator :4, skip_indicator:4; uint8_t system_information; } __attribute__ ((packed)); So, my first idea was that this is a bug of OsmocomBB, that would be fairly easy to fix, so after a quick look at the GSM 04.08 specification I wrote (and merged :/) this: https://gerrit.osmocom.org/#/c/5204/ And everything was great, until I connected a 'patched' mobile to a commercial mobile network... And all SI messages during a dedicated connection were false-identified as SI5ter. This seemed strange to me, so I decided to compare a SI message from commercial network with a message captured in my own one: https://habrastorage.org/webt/t8/zs/vv/t8zsvvjjglzfisnjqlnnsy4kgas.png And this confused me even more, then I've expected. Why there is 0x49? Wireshark false-identified this message as something related to SMS... What if this is exactly the 'l2_plen' assumed in OsmocomBB before? I looked at the specifications again, and found out that initially I refered an outdated 5.3.0 version, which was the first link in Google: http://www.etsi.org/deliver/etsi_gts/04/0408/05.03.00_60/gsmts_0408v050300p… while the latest one is 7.21.0: http://www.etsi.org/deliver/etsi_ts/100900_100999/100940/07.21.00_60/ts_100… So, I compared the 9.1.37-40 sections of both versions, and bingo! In the higher version ACCH System Information messages do have the 'L2 Pseudo Length' (10.5.2.19) field. Finally, what I've learned: - OsmocomBB / mobile follows the new version here (with l2_plen); - OsmoNiTB generates the ACCH SI messages without the l2_plen; - Recent Wireshark versions fail to decode the ACCH SI messages with l2_plen, while older ones are able to do that; - I should not merge the changes so quick. My questions are: - Which way of composing the SI messages is correct? - If both are correct, how to parse them correctly? - Should we change OsmoNiTB / OsmoBSC to follow the latest specs? And of course, I have to revert the change I've merged. With best regards, Vadim Yanitskiy.

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