Cellular Network Infrastructure » Core Network (CN) » OsmoSGSN

In a test lab installation using a non-osmocom BSS + 3G RAN, the SGSN every so often crashes with the following last lines:

The SGSN is crashing from time to time with:

Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:547 handle_co_initial(dir=1, proc=19)
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:174 New RNC 1203 at RI=2,PC=1204,SSN=142
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:257 RNC 1203: new LAC 123 RAC 1
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1561 MM(---/ffffffff) -> GMM RA UPDATE REQUEST type="periodic updating" 
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1636 MM(901700000040778/fa8d76a4) Looked up by matching TLLI and P_TMSI. BSSGP TLLI: 00000000, P-TMSI: fa8d76a4 (00000000), TLLI: fa8d76a4 (fa8d76a4), RA: 901-70-123-1
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm_fsm.c:170 MM_STATE_Gb(3572395996)[0x55d97cd93740]{Standby}: Event E_MM_IMPLICIT_DETACH not permitted
Jun 08 15:23:56 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1099 GMM(gmm_fsm)[0x55d97cd93610]{CommonProcedureInitiated}: Event E_GMM_COMMON_PROC_INIT_REQ not permitted
Jun 08 15:23:57 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:570 handle_co(dir=2, proc=6)
Jun 08 15:23:57 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1430 MM(901700000040778/fa8d76a4) <- ROUTING AREA UPDATE ACCEPT
Jun 08 15:23:57 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:570 handle_co(dir=1, proc=20)
Jun 08 15:23:57 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1757 MM(901700000040778/fa8d76a4) -> ROUTING AREA UPDATE COMPLETE
Jun 08 15:23:57 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1765 MM_STATE_Iu[0x55d97cd97350]{Detached}: Event E_PMM_RA_UPDATE not permitted
Jun 08 15:25:50 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:570 handle_co(dir=1, proc=11)
Jun 08 15:25:50 osmo-cn osmo-sgsn[4976]: <0018> iu_client.c:570 handle_co(dir=2, proc=1)
Jun 08 15:25:50 osmo-cn osmo-sgsn[4976]: <0002> gprs_ranap.c:135 MM(901700000040778/fa8d76a4) IU release for imsi 901700000040778
Jun 08 15:28:15 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:1021 MM(901700000040778/fa8d76a4) Cancelled, deleting context silently
Jun 08 15:28:15 osmo-cn osmo-sgsn[4976]: <0002> gprs_gmm.c:193 MM(901700000040778/fa8d76a4) Cleaning MM context due to access cancelled
Jun 08 15:28:15 osmo-cn osmo-sgsn[4976]: Assert failed mm->gb.llme == NULL gprs_sgsn.c:358

any ideas?

I will of course try to create better traces (combined pcap with GSMTAP libosmocore logs) but this may take some time.