Osmocom Libraries » libosmocore

If libosmogb implements the SGSN role of IP-SNS, it sends NS-ALIVE way too early.

Normally we would expect the following order of events:

1. Rx SNS-SIZE
2. Tx SNS-SIZE-ACK
3. Rx SNS-CONFIG
4. Tx SNS-CONFIG-ACK
5. Tx SNS-CONFIG
6. Rx SNS-CONFIG-ACK

Only after that last step, NS-ALIVE shalle be sent on all configured NSVC (which may not include the initial EP on which we just performed the SNS procedures).

The observed behavior shows that we start sending NS-ALIVE already after the very first SNS-SIZE from the PCU:

Thu Apr  1 18:58:22 2021 DLNS fsm.c:461 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: Allocated
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:2085 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: Received Event REQ_ADD_BIND
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:1502 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: Received Event REQ_SELECT_ENDPOINT
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:1502 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: Event REQ_SELECT_ENDPOINT not permitted
Thu Apr  1 18:58:22 2021 DLNS fsm.c:461 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNCONFIGURED}: Allocated
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:770 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNCONFIGURED}: Received Event REQ-START
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:274 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNCONFIGURED}: State change to UNBLOCKED (no timeout)
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2.c:565 NSE(02001) NS-STATUS.ind(bvci=00000): cause=NSE recovery, transfer=100, first=1, mtu=65527
Thu Apr  1 18:58:22 2021 DGPRS gb_proxy.c:1535 NS-NSE 2001 became available
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2.c:561 NSE(02001)-NSVC(none) NS-STATUS.ind(bvci=00000): cause=NSVC recovery, transfer=100, first=0, mtu=65527
Thu Apr  1 18:58:22 2021 DGPRS gb_proxy.c:1591 NS: Unknown NS-STATUS.ind cause=NSVC recovery from NS
Thu Apr  1 18:58:22 2021 DLNSSIGNAL gprs_ns2_message.c:203 NSE(02001)-NSVC(none) Tx NS-ALIVE
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:177 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNBLOCKED}: Starting Tns-alive of 3 seconds
Thu Apr  1 18:58:22 2021 DLNSSIGNAL gprs_ns2.c:1267 NSE(02001)-NSVC(none) Rx SNS-SIZE
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:1671 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: NSEI=2001 Rx SNS PDU type SNS-SIZE
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:1676 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: Received Event RX_SIZE
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:2353 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: State change to UNCONFIGURED (no timeout)
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:779 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNBLOCKED}: Received Event REQ-FORCE_UNCONFIGURED
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:686 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNBLOCKED}: State change to UNCONFIGURED (no timeout)
Thu Apr  1 18:58:22 2021 DLNSSIGNAL gprs_ns2_message.c:722 NSE(02001)-NSVC(none) Tx SNS-SIZE-ACK cause=NULL
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_sns.c:2374 GPRS-NS2-SNS-SGSN(NSE00000-SNS)[0x612000002920]{UNCONFIGURED}: State change to SGSN_WAIT_CONFIG (no timeout)
Thu Apr  1 18:58:22 2021 DLNSSIGNAL gprs_ns2.c:1267 NSE(02001)-NSVC(none) Rx NS-ALIVE-ACK
Thu Apr  1 18:58:22 2021 DLNS gprs_ns2_vc_fsm.c:877 GPRS-NS2-VC(UDP-NSE02001-remote-127_0_1_1:21010)[0x612000002c20]{UNCONFIGURED}: Received Event RX-ALIVE_ACK