diff --git a/protos/core_adapter.proto b/protos/core_adapter.proto
index 5021b9a..d828194 100644
--- a/protos/core_adapter.proto
+++ b/protos/core_adapter.proto
@@ -1,6 +1,9 @@
 syntax = "proto3";
 
 import "google/protobuf/any.proto";
+import "openflow_13.proto";
+import public "logical_device.proto";
+
 
 option go_package = "github.com/opencord/voltha-go/protos/core_adapter";
 
@@ -18,8 +21,14 @@
     bool val = 1;
 }
 
+enum ErrorCode {
+        UNSUPPORTED_REQUEST = 0;
+        INVALID_PARAMETERS = 1;
+}
+
 message Error {
-    string reason = 1;
+    ErrorCode code = 1;
+    string reason = 2;
 }
 
 enum MessageType {
@@ -56,3 +65,12 @@
     bool success = 1;
     google.protobuf.Any result = 3;
 }
+
+message SwitchCapability {
+    openflow_13.ofp_desc desc = 1;
+    openflow_13.ofp_switch_features switch_features = 2;
+}
+
+message PortCapability {
+    LogicalPort port = 1;
+}
\ No newline at end of file
diff --git a/protos/device.proto b/protos/device.proto
index f991e44..9c2d98c 100644
--- a/protos/device.proto
+++ b/protos/device.proto
@@ -250,10 +250,10 @@
         uint32 onu_session_id = 4; // session identifier for the ONU; optional
     };
 
-    oneof address {
-        // Device contact MAC address (format: "xx:xx:xx:xx:xx:xx")
-        string mac_address = 13;
+    // Device contact MAC address (format: "xx:xx:xx:xx:xx:xx")
+    string mac_address = 13;
 
+    oneof address {
         // Device contact IPv4 address (format: "a.b.c.d" or can use hostname too)
         string ipv4_address = 14;
 
diff --git a/protos/ponsim.proto b/protos/ponsim.proto
index 2ed8914..e477d98 100644
--- a/protos/ponsim.proto
+++ b/protos/ponsim.proto
@@ -8,9 +8,14 @@
 import "openflow_13.proto";
 
 
+message PonSimOnuDeviceInfo {
+    int32 uni_port = 1;
+    string serial_number = 2;
+}
+
 message PonSimDeviceInfo {
     int32 nni_port = 1;
-    repeated int32 uni_ports = 2;
+    repeated PonSimOnuDeviceInfo onus = 2;
 }
 
 message FlowTable {
@@ -21,6 +26,7 @@
 message PonSimFrame {
     string id = 1;
     bytes payload = 2;
+    int32 out_port = 3;
 }
 
 message PonSimPacketCounter {
diff --git a/protos/voltha.proto b/protos/voltha.proto
index 562ed60..92d59dd 100644
--- a/protos/voltha.proto
+++ b/protos/voltha.proto
@@ -72,6 +72,7 @@
 
 message Logging {
     LogLevel.LogLevel level = 1;
+    string package_name = 2;
 }
 
 // Top-level (root) node for a Voltha Instance