diff --git a/hnbgw/HNBGW_Tests.ttcn b/hnbgw/HNBGW_Tests.ttcn
index 2aa6407..5a2c72e 100644
--- a/hnbgw/HNBGW_Tests.ttcn
+++ b/hnbgw/HNBGW_Tests.ttcn
@@ -561,11 +561,25 @@
 	return rx;
 }
 
+/* 3GPP TS 48.006 9.2 Connection release:
+ *
+ *  The MSC sends a SCCP released message. This message shall not contain
+ *  any user data field.
+ *
+ * So what we expect normally is:
+ *
+ *                            HNBGW                    MSC
+ *  RUA --id-Disconnect-------> | ---Data-Form-1(!)---> |  Iu-ReleaseComplete
+ *                              | <--Released---------- |  (no data)
+ *
+ * This function tests osmo-hnbgw behavior if the CN fails to send a RLSD:
+ * after some timeout, osmo-hnbgw should send a RLSD to the CN.
+ */
 function f_iuh2iu_disconnect(template (present) RANAP_PDU tx, RUA_IEs.Cause cause,
 			     template RANAP_PDU exp_rx := omit)
 runs on ConnHdlr return RANAP_PDU {
 	var RANAP_PDU rx
-	timer T := 5.0;
+	timer T := 10.0;
 
 	if (istemplatekind(exp_rx, "omit")) {
 		exp_rx := tx;