diff --git a/library/RSL_Types.ttcn b/library/RSL_Types.ttcn
index 336b042..1d68969 100644
--- a/library/RSL_Types.ttcn
+++ b/library/RSL_Types.ttcn
@@ -1453,13 +1453,12 @@
 		}
 	}
 
-	template RSL_Message ts_RSL_IPA_DLCX(RslChannelNr chan_nr,
-					     template (omit) uint16_t ipa_conn_id := omit) := {
+	template RSL_Message ts_RSL_IPA_DLCX(RslChannelNr chan_nr, uint16_t ipa_conn_id) := {
 		msg_disc := ts_RSL_MsgDisc(RSL_MDISC_IPACCESS, false),
 		msg_type := RSL_MT_IPAC_DLCX,
 		ies := {
-			t_RSL_IE(RSL_IE_CHAN_NR, RSL_IE_Body:{chan_nr := chan_nr})
-			/* FIXME: optional conn_id */
+			t_RSL_IE(RSL_IE_CHAN_NR, RSL_IE_Body:{chan_nr := chan_nr}),
+			t_RSL_IE(RSL_IE_IPAC_CONN_ID, RSL_IE_Body:{ipa_conn_id := ipa_conn_id})
 		}
 	}
 	template RSL_Message tr_RSL_IPA_DLCX(template RslChannelNr chan_nr,