diff --git a/adaptercore/olt_platform.go b/adaptercore/olt_platform.go
new file mode 100644
index 0000000..542192f
--- /dev/null
+++ b/adaptercore/olt_platform.go
@@ -0,0 +1,154 @@
+/*
+ * 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 adaptercore
+import (voltha "github.com/opencord/voltha-go/protos/voltha");
+
+/*=====================================================================
+
+Flow id
+
+    Identifies a flow within a single OLT
+    Flow Id is unique per OLT
+    Multiple GEM ports can map to same flow id
+
+     13    11              4      0
+    +--------+--------------+------+
+    | pon id |    onu id    | Flow |
+    |        |              | idx  |
+    +--------+--------------+------+
+
+    14 bits = 16384 flows (per OLT).
+
+    pon id = 4 bits = 16 PON ports
+    onu id = 7 bits = 128 ONUss per PON port
+    Flow index = 3 bits = 4 bi-directional flows per ONU
+                        = 8 uni-directional flows per ONU
+
+
+Logical (OF) UNI port number
+
+    OpenFlow port number corresponding to PON UNI
+
+     15       11              4      0
+    +--+--------+--------------+------+
+    |0 | pon id |    onu id    |   0  |
+    +--+--------+--------------+------+
+
+    pon id = 4 bits = 16 PON ports
+    onu id = 7 bits = 128 ONUs per PON port
+
+Logical (OF) NNI port number
+
+    OpenFlow port number corresponding to PON UNI
+
+     16                             0
+    +--+----------------------------+
+    |1 |                    intf_id |
+    +--+----------------------------+
+
+    No overlap with UNI port number space
+
+
+PON OLT (OF) port number
+
+    OpenFlow port number corresponding to PON OLT ports
+
+     31    28                                 0
+    +--------+------------------------~~~------+
+    |  0x2   |          pon intf id            |
+    +--------+------------------------~~~------+
+*/
+
+var MAX_ONUS_PER_PON = 32;
+var MIN_UPSTREAM_PORT_ID = 0xfffd;
+var MAX_UPSTREAM_PORT_ID = 0xfffffffd;
+
+func MkUniPortNum(intfId uint32, onuId uint32, uniId uint32) uint32 {
+/* TODO: Add checks */
+        return ((intfId << 11) | (onuId << 4) | uniId)
+}
+
+func MkFlowId(intfId uint32, onuId uint32, idx uint32) uint32 {
+	return (((intfId << 9) | (onuId << 4)) | idx)
+}
+
+func OnuIdFromPortNum(portNum uint32) uint32 {
+	return ((portNum >> 4) & 127)
+}
+
+func IntfIdFromUniPortNum(portNum uint32) uint32 {
+	return ((portNum >> 11) & 15)
+}
+
+func UniIdFromPortNum(portNum uint32) uint32 {
+        return ((portNum) & 0xF)
+}
+
+
+
+func IntfIdFromPonPortNo(portNo uint32) uint32 {
+	return (portNo & 15)
+}
+
+func IntfIdToPortNo(intfId uint32, intfType voltha.Port_PortType) uint32 {
+	if (( intfType ) == voltha.Port_ETHERNET_NNI) {
+		return ((1 << 16) | intfId)
+	} else {
+		if (( intfType ) == voltha.Port_PON_OLT) {
+			return ((2 << 28) | intfId)
+		} else {
+			return 0
+		}
+	}
+}
+
+func IntfIdFromNniPortNum(portNum uint32) uint32 {
+	return (portNum & 0xFFFF)
+}
+
+func IntfIdToPortTypeName(intfId uint32) voltha.Port_PortType {
+	if (( ((2 << 28) ^ intfId) ) < 16) {
+		return voltha.Port_PON_OLT
+	} else {
+		if ( (intfId & (1 << 16)) ) == ( (1 << 16) ) {
+			return voltha.Port_ETHERNET_NNI
+		} else {
+			return voltha.Port_UNKNOWN
+		}
+	}
+}
+
+func PortTypeNameByPortIndex(portIndex int32) string {
+	return voltha.Port_PortType_name[portIndex]
+}
+
+func ExtractAccessFromFlow(inPort uint32, outPort uint32) (uint32, uint32, uint32, uint32) {
+	if (IsUpstream(outPort)) {
+                return inPort, IntfIdFromUniPortNum(inPort), OnuIdFromPortNum(inPort), UniIdFromPortNum(inPort)
+	} else {
+                return outPort, IntfIdFromUniPortNum(outPort), OnuIdFromPortNum(outPort), UniIdFromPortNum(outPort)
+	}
+}
+
+func IsUpstream(outPort uint32) bool {
+	if ((outPort >= uint32(MIN_UPSTREAM_PORT_ID)) && (outPort <= uint32(MAX_UPSTREAM_PORT_ID))) {
+		return true
+	}
+	if ( (outPort & (1 << 16)) ) == ( (1 << 16) ) {
+		return true
+	}
+	return false
+}