library/DIAMETER_Emulation: handle DWR/DWA ping-pong

Change-Id: I0291eccd0467f8fe15ddcb88259618365c33befd
Related: SYS#5602
diff --git a/library/DIAMETER_Emulation.ttcn b/library/DIAMETER_Emulation.ttcn
index f7a0f88..220ab11 100644
--- a/library/DIAMETER_Emulation.ttcn
+++ b/library/DIAMETER_Emulation.ttcn
@@ -328,6 +328,14 @@
 			/* notify our user that the CER->CEA exchange has happened */
 			DIAMETER_UNIT.send(DiameterCapabilityExchgInd:{rx:=mrf.msg, tx:=valueof(resp)});
 			}
+		/* handle DWR/DWA ping-pong */
+		[] DIAMETER.receive(tr_DIAMETER_RecvFrom_R(tr_DIA_DWR)) -> value mrf {
+			var template (value) PDU_DIAMETER resp;
+			resp := ts_DIA_DWA('00000001'O, p.origin_host, p.origin_realm,
+					   hbh_id := mrf.msg.hop_by_hop_id,
+					   ete_id := mrf.msg.end_to_end_id);
+			DIAMETER.send(t_DIAMETER_Send(g_diameter_conn_id, valueof(resp)));
+			}
 
 		/* DIAMETER from remote peer */
 		[] DIAMETER.receive(tr_DIAMETER_RecvFrom_R(?)) -> value mrf {