Refactoring file structure for protobufs.

Change-Id: I50daf100d54750f97158304d87813e67861b1422
diff --git a/incubator/protobuf/models/src/main/proto/PortEnums.proto b/incubator/protobuf/models/src/main/proto/PortEnums.proto
new file mode 100644
index 0000000..b05efc4
--- /dev/null
+++ b/incubator/protobuf/models/src/main/proto/PortEnums.proto
@@ -0,0 +1,23 @@
+syntax = "proto3";
+option java_package = "org.onosproject.grpc.net.models";
+
+package Port;
+
+enum PortType {
+    // Signifies copper-based connectivity.
+    COPPER = 0;
+    // Signifies optical fiber-based connectivity.
+    FIBER = 1;
+    // Signifies optical fiber-based packet port.
+    PACKET = 2;
+    // Signifies optical fiber-based optical tributary port (called T-port).
+    //The signal from the client side will be formed into a ITU G.709 (OTN) frame.
+    ODUCLT = 3;
+    // Signifies optical fiber-based Line-side port (called L-port).
+    OCH = 4;
+    // Signifies optical fiber-based WDM port (called W-port).
+    //Optical Multiplexing Section (See ITU G.709).
+    OMS = 5;
+    // Signifies virtual port.
+    VIRTUAL = 6;
+}
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