OpenBSC August 2019

openbsc@lists.osmocom.org

9 participants
15 discussions

Diameter to GSUP translator
by Harald Welte 15 Aug '19

15 Aug '19

Hi all, as some of you know, I've been working on a small diameteer to GSUP translator, which allows us to connect a MME like nextepc-mme against osmo-hlr. The code is still a big ugly hack and needs cleanup, but today I finally got it to work for authentication and location update. In case anyone is curious how this looks like, I've attached a pcap file that includes the S1AP, DIAMETER, GSUP and GTPv2C traffic of an initial LTE registration happening on a setup running the following programs: * nextepc MME, SGW, PGW, PCRF * osmo_diameter2gsup * osmo-hlr The point of this is to enable networks to run a shared subscriber database for 2G, 3G and 4G, which is a very typical use case if you have existing Osmocom based network and want to extend it with LTE. We will test this translator extensively at the upcoming CCC Camp, where all three (2G, 3G and 4G) networks will be running. The sad part is that we don't yet have a common GGSN and P-GW, which means that the PDP/PDN context including the IP address will not persist when moving between 2G+3G on the one hand side and 4G on the other hand side. I expect to get the commit history cleaned up and plan to push the [Erlang] code to git.osmocom.org tomorrow. 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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3G handover (+ 35C3 experience)
by Mykola Shchetinin 15 Aug '19

15 Aug '19

Hello, dear Community, Has anybody tested how cell handover works in 3G with Osmocom software? 3G network was set up for 35C3: I would like to ask whether anybody noticed if a cell was reselected "smoothly" by the phone when the user was moving or it was like a drop of a connection and reconnection to a different cell afterwards? So, basically, the question is: Does the handover work in 3G Osmocom? (single HNBGW and MSC/SGSN) Thanks. Kind regards, Mykola

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201908 Osmocom CNI Release
by Pau Espin Pedrol 08 Aug '19

08 Aug '19

Hi, I have been releasing new tagged versions of Osmocom CNI (Osmocom Cellular Network Infrastructure) related projects over last days this week. New released versions: libosmocore 1.2.0 libosmo-abis 0.7.0 libosmo-netif 0.6.0 libusrp 3.4.4 libgtpnl 1.2.1 osmo-trx 1.1.1 osmo-pcu 0.7.0 osmo-ggsn 1.4.0 osmo-pcap 0.1.1 libasn1c 0.9.32 libsmpp34 1.14.0 osmo-bts 1.1.0 osmo-hlr 1.1.0 libosmo-sccp 1.1.0 osmo-mgw 1.6.0 osmo-iuh 0.5.0 osmo-bsc 1.5.0 osmo-msc 1.5.0 osmo-sgsn 1.5.0 openbsc 1.3.1 osmo-sip-connector 1.3.0 Some patch releases may come tomorrow in the event some unexpected error shows up during repository build process. Please, to get the latest tags applied, remember to fetch them and clean up the .version related files. Something like this will do the job (be careful, git clean may remove some of your changes in the git repo): $ git fetch --tags; git clean -fxd Updated tags in OE meta-telephony 201705 will come during current ot next week. Regards, -- - Pau Espin Pedrol <pespin(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Director: Harald Welte

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Failure to activate sigtran stack when using IPA on osmo-bsc
by Roch-Alexandre Nominé 07 Aug '19

07 Aug '19

Hi, I’m trying to configure osmo-bsc to connect to an IPA based MSC and get a failure when activating the sigtran stack. Here’s the log: root@sysmobts-v2:/etc/osmocom# osmo-bsc -c /etc/osmocom/osmo-bsc.cfg <001d> ../../git/src/osmo_ss7.c:1269 0: ASP Restart for server not implemented yet! % Ignoring deprecated logging level everything % Ignoring deprecated logging level everything % dyn_ts_allow_tch_f is deprecated, rather use msc/codec-list to pick codecs <0011> ../../../git/src/vty/telnet_interface.c:104 telnet at 0.0.0.0 4242 <0013> ../../git/src/input/ipaccess.c:853 enabling ipaccess BSC mode on 0.0.0.0 with OML 3002 and RSL 3003 TCP ports <0018> ../../../git/src/ctrl/control_if.c:866 CTRL at 0.0.0.0 4249 <0008> ../../../git/src/osmo-bsc/osmo_bsc_sigtran.c:427 Initializing SCCP connection to MSC msc-0 <0008> ../../../git/src/osmo-bsc/osmo_bsc_sigtran.c:437 CS7 Instance identifier, A-Interface: 0 <001e> ../../git/src/sccp_user.c:397 msc-0: Using SS7 instance 0, pc:0.23.3 <001e> ../../git/src/sccp_user.c:411 msc-0: Creating AS instance <0005> ../../../git/src/osmo-bsc/osmo_bsc_main.c:504 Failed to initalize sigtran backhaul. I used the configuration posted by Harald part of ticker https://osmocom.org/issues/2544 https://osmocom.org/attachments/3154/osmo-bsc.cfg.ipa and get the same result. How can I troubleshoot further in order to know what’s happening? Best regards Roch.

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interfacing core network to SIP world
by Keith 05 Aug '19

05 Aug '19

Hi all, Doing some testing recently with osmo-sip-connector, I noticed a few things that seem to be important regarding the user experience of a network with osmo-sip-connector. * The osmo-sip-connector is an external MNCC handler interface for one MSC. The MSC doesn't have any information about what is in the HLR. When the osmo-sip-connector sends a call towards the MSC, the msc does a VLR lookup: vlr_subscr_find_by_msisdn() in gsm_04_08_cc.c around line 1860. if that returns false we are doing mncc_release_ind() with GSM48_CC_CAUSE_UNASSIGNED_NR. That is getting translated into a SIP 404, which informs the caller that the number was not found. Logical but it's not correct if the subscriber does actually exist in the HLR. Actually the same problem exists when using the internal MNCC, If you call a subscriber that has just switched off their phone, you'll get an Un Assigned Number error cause. That would be incredibly confusing for the users. In rhizomatica's case, the audio played back to the caller would be "The number you have dialed does not exist, please verify it", while it should obviously be "The number you have dialed is temporarily unavailable, please try again later." What we have done there is send the caller to go physically ask ask the callee why they canceled their phone service, when all they did was switch off the phone. SO: There was some discussion about this at the devcon, I want to outline some points here, hopefully I understand it right. * The osmo-sip-connector should ask the HLR if the number exists before forwarding the call to MNCC. * There may be more than one MSC, in which case the HLR would inform osmo-sip-connector about which MSC to use. * The osmo-sip-connector could either be SIP associated, or MSC associated, that is to say: a) one osmo-sip-connector per SIP UA, sip-connector talks to HLR, and has multiple connections to MSCs (UDP then, not Unix Socket?) or b) one osmo-sip-connector per MSC, in which case the SIP UA would have to somehow query the HLR to ask where to send the call. Does that all sound correct? and then.. still a doubt: IIUC, in the traditional core network. When an MSC receives a MO SETUP from a local MS, and it does not have this number in the VLR, it should be querying HLR for routing info, (which may subsequently query another HLR) no? why are we only doing VLR lookup in the MSC? Is it simply "To be implemented" ? thanks! k/

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OpenBSC August 2019