diff --git a/omci_sim.go b/omci_sim.go
new file mode 100644
index 0000000..8c5a12a
--- /dev/null
+++ b/omci_sim.go
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package core
+
+import (
+	logger "github.com/sirupsen/logrus"
+)
+
+func OmciSim(intfId uint32, onuId uint32, request []byte) ([]byte, error) {
+	var resp []byte
+
+	transactionId, deviceId, msgType, class, instance, content, err := ParsePkt(request)
+	if err != nil {
+		return resp, &OmciError{"Cannot parse omci msg"}
+	}
+
+	logger.Debug("OmciRun - transactionId: %d msgType: %d, ME Class: %d, ME Instance: %d",
+		transactionId, msgType, class, instance)
+
+	key := OnuKey{intfId, onuId}
+	if _, ok := OnuOmciStateMap[key]; !ok {
+		OnuOmciStateMap[key] = NewOnuOmciState()
+	}
+
+	if _, ok := Handlers[msgType]; !ok {
+		logger.Warn("Ignore omci msg (msgType %d not handled)", msgType)
+		return resp, &OmciError{"Unimplemented omci msg"}
+	}
+
+	resp, err = Handlers[msgType](class, content, key)
+	if err != nil {
+		return resp, err
+	}
+	resp[0] = byte(transactionId >> 8)
+	resp[1] = byte(transactionId & 0xFF)
+	resp[2] = 0x2<<4 | byte(msgType)
+	resp[3] = deviceId
+
+	return resp, nil
+}