This Iu timer is Osmocom specific, but is made to resemble T3314
timer from GERAN (also named READY timer).
The idea of this activity timer was to arm it whenever PMM state
transitions to CONNECTED, and then rearm it every time there's some
sort of activity, until there's none for some time, then we send a
Release Command to close the conn with the HNGBW/RNC. That's the
same principle as per spec-defined READY timer T3314.
However, there's still a fundamental problem with it: GTP-U in
GERAN passes through the SGSN, but in UTRAN, the GTP-U stream
goes directly from the HnodeB to the GGSN. Hence, there's no proper
way to re-arm this timer upon activity in UTRAN, basically because
the SGSN will never see (userplane data) activity. That explains why
the E_MM_PDU_RECEPTION event exists for mm_state_gb_fsm, but doesn't
exist for mm_state_iu_fsm.
As a result, the timer is currently never rearmed, which means it
will transition to IDLE always after 44 seconds (default value) once
it went into CONNECTED state.
In UTRAN, there is a SCCP connection for each subscriber between
RNC/hNB and SGSN. If the subscriber is no longer in the respective
state, the RNC/hNB should release that IuPS SCCP connection, whcih
in turn means the SGSN cleans up its state.
Furthermore, SCCP has a built-in IT (inactivity timer). So should
the RNC/hNB die, that timer would time out, and the SGSN-side local
SCCP stack (provider) wold send a RELEASE.ind for that connection
to the user (SGSN).
TLDR; this timer is not really needed and cannot be implemented
properly in UTRAN, so let's remove it.
Related: OS#5116
Change-Id: Ibc71829e417bf2dd0c27deb842369dd4f17010d6
The new NS2 api supports NSE with multiple NS-VC and contains a NS-VC
fsm. FR/GRE support is not working.
The configuration is compatible except for FR/GRE.
Relates: OS#4629
Depends-on: Iaad7b53d44338e5dd81dc2202f23bdcb715af804 (libosmocore)
Depends-on: I6cef42749555e577d5573f2ed8b8bce4cf842a98 (libosmocore)
Change-Id: I92a3bcaf166b091a22d74c7c1586964d33d7cc9d
gprs_subscr_get_or_create() can return NULL if no memory can
be allocated. Detected by the compiler on Ubuntu s390x.
Signed-off-by: Steve Langasek <steve.langasek@ubuntu.com>
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Change-Id: I86b3652d46bdd581fe6cbab16b52395a0daaa082
The SGSN initialises GTP with gtp_statedir of "./" which may
not be the desired path for writing the gsn_restart file.
When starting from systemd for example, we might write
to the system root.
This patch allows override via the config file.
Closes: OS#4820
Change-Id: Ib3ffb7fd6ea1d9b0286111d8c2cba9da5394ca58
When the SGSN releases a RANAP connection, it sends a Release Command
and waits for a Release Complete. Use X1001 to release the Iu connection
when the Release Complete is lost/never received.
Change-Id: I39a0169c22a4ac430b3d6f3c281d1f381eaa4756
The user inactivity timer is similiar to the Gb READY timer and reduces
the resources taken by an idle UE.
Change-Id: I66c2ac0350cb074aefd9a22c5121acf723f239d3
State machine inspired in the one from TS 24.008 4.1.3.3.1. Some state
transitions are inroduced in the code but are still commented out since
we lack some functionalitites or improvements in the code to handle
different scenarios.
Most of the logic is still outside of the FSM, but at least now the
states are handled in a sane way triggered by events.
Change-Id: Idecb43c10d66224d4f9ba9320825040ce6cf9a07
Pau Espin
Alexander Couzens
Keith Whyte