pespin has uploaded this change for review.
Fix SCCP RLSD not sent upon rx RUA Disconnect due to error condition
Scenario: HNB tears down the RUA/Iu conn by first sending
RUA_DATA[RANAP IuReleaseReq], followed shortly by a RUA Disconnect with no
RANAP and Cause!=Normal. HNBGW should release the SCCP connection through
RLSD since it's impossible to terminate the Iu connection in a normal
condition.
Validated with TTCN-3 HNBGW_Tests.TC_cs_iu_release_req_rua_disconnect.
Related: osmo-ttcn3-hacks.git Change-Id I6782920c4a86d3311eb54239ab13a18e393c1ec0
Related: SYS#6602
Change-Id: I1b7f72034eaf40bfa60d552d434847467ac4e97a
---
M src/osmo-hnbgw/context_map_sccp.c
1 file changed, 15 insertions(+), 5 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-hnbgw refs/changes/81/38581/1
diff --git a/src/osmo-hnbgw/context_map_sccp.c b/src/osmo-hnbgw/context_map_sccp.c
index 511577c..881d5ce 100644
--- a/src/osmo-hnbgw/context_map_sccp.c
+++ b/src/osmo-hnbgw/context_map_sccp.c
@@ -364,11 +364,21 @@
return;
case MAP_SCCP_EV_RAN_DISC:
- /* RUA has disconnected, and usually has sent an Iu-ReleaseComplete along with its RUA Disconnect. On
- * SCCP, the Iu-ReleaseComplete should still be forwarded as N-Data (SCCP Data Form 1), and we will
- * expect the CN to send an SCCP RLSD soon. */
- map_sccp_fsm_state_chg(MAP_SCCP_ST_WAIT_RLSD);
- tx_sccp_df1(fi, ranap_msg);
+ /* 3GPP TS 25.468 9.1.5: RUA has disconnected.
+ * - Under normal conditions (cause=Normal) the RUA Disconnect contains a RANAP Iu-ReleaseComplete.
+ * On SCCP, the Iu-ReleaseComplete should still be forwarded as N-Data SCCP Data Form 1),
+ * and we will expect the CN to send an SCCP RLSD soon.
+ * - Under error conditions, cause!=Normal and the's no RANAP message.
+ * In that case, we need to tear down the associated SCCP link towards CN,
+ * which in turn will tear down the upper layer Iu conn.
+ */
+ if (msg_has_l2_data(ranap_msg)) {
+ map_sccp_fsm_state_chg(MAP_SCCP_ST_WAIT_RLSD);
+ tx_sccp_df1(fi, ranap_msg);
+ } else {
+ tx_sccp_rlsd(fi);
+ map_sccp_fsm_state_chg(MAP_SCCP_ST_DISCONNECTED);
+ }
return;
case MAP_SCCP_EV_RAN_LINK_LOST:
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