<p>Minh-Quang Nguyen has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bsc/+/15909">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">RSL: Wrong CCCH_CONFIG in SI3 causes a lot of MO call setup failed when the BTS configured with none combined CCCH mode.<br><br>Issue:<br>MO call setup signaling failed when the CCCH is configured in none combined with SDCCH (a dedicated TS is configured for SDCCH). The call setup signaling attempts in all SDCCH sub-channels until the MO call setup failed as shown below:<br><br><0007> ../../../git/src/osmo-bsc/osmo_bsc_sigtran.c:305 Initializing resources for new SIGTRAN connection to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP...<br><0007> ../../../git/src/osmo-bsc/osmo_bsc_sigtran.c:351 Opening new SIGTRAN connection (id=1) to MSC: RI=SSN_PC,PC=0.23.1,SSN=BSSAP<br><0010> ../../../git/src/osmo-bsc/lchan_fsm.c:80 lchan(0-0-1-SDCCH8-0)[0x1eb888]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout<br><0007> ../../../git/src/osmo-bsc/osmo_bsc_bssap.c:584 SUBSCR_CONN(conn1)[0x249298]{ACTIVE}: Global Call Ref IE of 0 bytes is too short<br><0010> ../../../git/src/osmo-bsc/lchan_fsm.c:80 lchan(0-0-1-SDCCH8-1)[0x1eb9c8]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout<br><0010> ../../../git/src/osmo-bsc/lchan_fsm.c:80 lchan(0-0-1-SDCCH8-2)[0x246e08]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout<br><0010> ../../../git/src/osmo-bsc/lchan_fsm.c:80 lchan(0-0-1-SDCCH8-3)[0x246f48]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout<br><0010> ../../../git/src/osmo-bsc/lchan_fsm.c:80 lchan(0-0-1-SDCCH8-4)[0x247088]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout<br><0000> ../../../git/src/libosmo-mgcp-client/mgcp_client_fsm.c:526 MGCP_CONN(to-MSC)[0x24a1f8]{ST_READY}: MGW/DLCX: abrupt FSM termination with connections still present, sending unconditional DLCX...<br><0000> ../../../git/src/libosmo-mgcp-client/mgcp_client_fsm.c:526 MGCP_CONN(to-BTS)[0x251a58]{ST_READY}: MGW/DLCX: abrupt FSM termination with connections still present, sending unconditional DLCX...<br><0010> ../../../git/src/osmo-bsc/abis_rsl.c:2018 lchan(0-0-2-TCH_F-0)[0x2475e0]{WAIT_RF_RELEASE_ACK}: (type=TCH_F) Rx IPACC DLCX IND<br><br>After an investigation, it turns out that the BTS broadcasts wrong CCCH_CONF=1, i.e. combined CCCH and SDCCH instead of CCCH_CONF=0, i.e. none combined CCCH.<br><br>Fixes:<br>- The generation of SI3 looks for CCCH information in BTS->C0 timeslots configuration that have never been updated during parsing the BSC configuration file.<br>- Properly update BTS->C0 timeslots configuration during parsing the BSC configuration file solves the issue.<br><br>Change-Id: I33ea7808ac1bd064b88fd609bd7dfe0c8aa341f2<br>---<br>M src/osmo-bsc/bsc_vty.c<br>1 file changed, 4 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/09/15909/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/osmo-bsc/bsc_vty.c b/src/osmo-bsc/bsc_vty.c</span><br><span>index a388c9a..6e02e06 100644</span><br><span>--- a/src/osmo-bsc/bsc_vty.c</span><br><span>+++ b/src/osmo-bsc/bsc_vty.c</span><br><span>@@ -4336,6 +4336,10 @@</span><br><span> </span><br><span>   ts->pchan_from_config = pchanc;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+        /* update BTS->C0 timeslot configuration so that CCCH_CONF in SI3 will be correctly generated */</span><br><span style="color: hsl(120, 100%, 40%);">+   if (ts->trx == ts->trx->bts->c0)</span><br><span style="color: hsl(120, 100%, 40%);">+          ts->trx->bts->c0->ts[ts->nr].pchan_is = pchanc;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span>     return CMD_SUCCESS;</span><br><span> }</span><br><span> </span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bsc/+/15909">change 15909</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/osmo-bsc/+/15909"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: osmo-bsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I33ea7808ac1bd064b88fd609bd7dfe0c8aa341f2 </div>
<div style="display:none"> Gerrit-Change-Number: 15909 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Minh-Quang Nguyen <minh-quang.nguyen@nutaq.com> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>