diff --git a/omci_defs.go b/omci_defs.go
new file mode 100644
index 0000000..634d1d3
--- /dev/null
+++ b/omci_defs.go
@@ -0,0 +1,97 @@
+/*
+ * 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 (
+	"bytes"
+	"encoding/binary"
+	"errors"
+
+	logger "github.com/sirupsen/logrus"
+)
+
+//
+// OMCI definitions
+//
+
+// OmciMsgType represents a OMCI message-type
+type OmciMsgType byte
+
+const (
+	// Message Types
+	_                                 = iota
+	Create                OmciMsgType = 4
+	Delete                OmciMsgType = 6
+	Set                   OmciMsgType = 8
+	Get                   OmciMsgType = 9
+	GetAllAlarms          OmciMsgType = 11
+	GetAllAlarmsNext      OmciMsgType = 12
+	MibUpload             OmciMsgType = 13
+	MibUploadNext         OmciMsgType = 14
+	MibReset              OmciMsgType = 15
+	AlarmNotification     OmciMsgType = 16
+	AttributeValueChange  OmciMsgType = 17
+	Test                  OmciMsgType = 18
+	StartSoftwareDownload OmciMsgType = 19
+	DownloadSection       OmciMsgType = 20
+	EndSoftwareDownload   OmciMsgType = 21
+	ActivateSoftware      OmciMsgType = 22
+	CommitSoftware        OmciMsgType = 23
+	SynchronizeTime       OmciMsgType = 24
+	Reboot                OmciMsgType = 25
+	GetNext               OmciMsgType = 26
+	TestResult            OmciMsgType = 27
+	GetCurrentData        OmciMsgType = 28
+	SetTable              OmciMsgType = 29 // Defined in Extended Message Set Only
+)
+
+const (
+	// Managed Entity Class values
+	GEMPortNetworkCTP OmciClass = 268
+)
+
+// OMCI Managed Entity Class
+type OmciClass uint16
+
+// OMCI Message Identifier
+type OmciMessageIdentifier struct {
+	Class    OmciClass
+	Instance uint16
+}
+
+type OmciContent [32]byte
+
+type OmciMessage struct {
+	TransactionId uint16
+	MessageType   OmciMsgType
+	DeviceId      uint8
+	MessageId     OmciMessageIdentifier
+	Content       OmciContent
+}
+
+func ParsePkt(pkt []byte) (uint16, uint8, OmciMsgType, OmciClass, uint16, OmciContent, error) {
+	var m OmciMessage
+
+	r := bytes.NewReader(pkt)
+
+	if err := binary.Read(r, binary.BigEndian, &m); err != nil {
+		logger.Error("binary.Read failed: %s", err)
+		return 0, 0, 0, 0, 0, OmciContent{}, errors.New("binary.Read failed")
+	}
+	logger.Debug("OmciRun - TransactionId: %d MessageType: %d, ME Class: %d, ME Instance: %d, Content: %x",
+		m.TransactionId, m.MessageType&0x0F, m.MessageId.Class, m.MessageId.Instance, m.Content)
+	return m.TransactionId, m.DeviceId, m.MessageType & 0x0F, m.MessageId.Class, m.MessageId.Instance, m.Content, nil
+}