LCLS: Fix Global Call Reference generation
According to 3gpp spec the Call Reference part of GCR is 5 octets,
3 octets Call ID followed by 2 octets BSS ID.
We are using our internal call reference (4 octets) and the
location area code, or optionally Cell ID as BSS ID
(2 octets). Obviously it does not fit.
Let's use only 3 octets from the call reference, dropping the MSB.
Includes code by Vadim Yanitskiy <vyanitskiy@sysmocom.de>
Change-Id: I9c33a89c819e8925d89ca833d7705ed5ced6b566
diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c
index 25c0e3c..6c12409 100644
--- a/src/libmsc/transaction.c
+++ b/src/libmsc/transaction.c
@@ -153,11 +153,17 @@
/* net id from Q.1902.3 3-5 bytes, this function gives 3 bytes exactly */
osmo_plmn_to_bcd(lcls->gcr.net, &trans->net->plmn);
- osmo_store32be(trans->callref, lcls->gcr.cr);
- osmo_store16be(use_lac ? trans->msc_a->via_cell.lai.lac : trans->msc_a->via_cell.cell_identity, lcls->gcr.cr + 3);
- LOGP(DCC, LOGL_INFO, "LCLS: allocated %s-based CR-ID %s\n", use_lac ? "LAC" : "CI",
- osmo_hexdump(lcls->gcr.cr, 5));
+ /* TS 29.205 Table B.2.1.9.2 Call Reference ID
+ * 3 octets Call ID + 2 octets BSS ID
+ */
+ lcls->gcr.cr[2] = (trans->callref >> 0) & 0xff;
+ lcls->gcr.cr[1] = (trans->callref >> 8) & 0xff;
+ lcls->gcr.cr[0] = (trans->callref >> 16) & 0xff;
+ osmo_store16be(use_lac ? trans->msc_a->via_cell.lai.lac : trans->msc_a->via_cell.cell_identity, &lcls->gcr.cr[3]);
+
+ LOGP(DCC, LOGL_INFO, "LCLS: allocated %s-based CR-ID %sfor callref 0x%04x\n", use_lac ? "LAC" : "CI",
+ osmo_hexdump(lcls->gcr.cr, 5), trans->callref);
lcls->config = GSM0808_LCLS_CFG_BOTH_WAY;
lcls->control = GSM0808_LCLS_CSC_CONNECT;