diff --git a/pgw/PGW_Tests.ttcn b/pgw/PGW_Tests.ttcn
index cf3b901..c99302c 100644
--- a/pgw/PGW_Tests.ttcn
+++ b/pgw/PGW_Tests.ttcn
@@ -126,6 +126,26 @@
 	fn.apply();
 }
 
+private function f_concat_pad(integer tot_len, hexstring prefix, integer suffix) return hexstring {
+	var integer suffix_len := tot_len - lengthof(prefix);
+	var charstring suffix_ch := int2str(suffix);
+	var integer pad_len := suffix_len - lengthof(suffix_ch);
+
+	return prefix & int2hex(0, pad_len) & str2hex(suffix_ch);
+}
+
+function f_gen_imei(integer suffix) return hexstring {
+	return f_concat_pad(14, '49999'H, suffix);
+}
+
+function f_gen_imsi(integer suffix) return hexstring {
+	return f_concat_pad(15, '26242'H, suffix);
+}
+
+function f_gen_msisdn(integer suffix) return hexstring {
+	return f_concat_pad(12, '49123'H, suffix);
+}
+
 
 /* find TEID of given interface type (and optionally instance) */
 private function f_find_teid(FullyQualifiedTEID_List list,
@@ -385,6 +405,23 @@
 	vc_conn := f_start_handler(refers(f_TC_createSession_ping4), pars);
 	vc_conn.done;
 }
+testcase TC_createSession_ping4_256() runs on PGW_Test_CT {
+	var PGW_Session_CT vc_conn[256];
+	var integer i;
+
+	f_init();
+
+	for (i := 0; i < sizeof(vc_conn); i:=i+1) {
+		var charstring tundev := "ping" & int2str(i);
+		var SessionPars pars := valueof(t_SessionPars(f_gen_imsi(i), tundev));
+		vc_conn[i] := f_start_handler(refers(f_TC_createSession_ping4), pars);
+	}
+
+	for (i := 0; i < lengthof(vc_conn); i:=i+1) {
+		vc_conn[i].done;
+	}
+}
+
 
 /* create a session, then delete it again */
 private function f_TC_createSession_deleteSession() runs on PGW_Session_CT {
@@ -422,6 +459,7 @@
 	execute( TC_tx_echo() );
 	execute( TC_createSession() );
 	execute( TC_createSession_ping4() );
+	execute( TC_createSession_ping4_256() );
 	execute( TC_createSession_deleteSession() );
 	execute( TC_deleteSession_unknown() );
 }