diff --git a/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeUtils.java b/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeUtils.java
new file mode 100644
index 0000000..411e1fb
--- /dev/null
+++ b/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeUtils.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2017-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 org.onosproject.p4runtime.ctl;
+
+import com.google.protobuf.ByteString;
+
+import static java.lang.String.format;
+
+/**
+ * Utilities for P4 runtime control.
+ */
+public final class P4RuntimeUtils {
+
+    private P4RuntimeUtils() {
+        // Hide default construction
+    }
+
+    static void assertSize(String entityDescr, ByteString value, int bitWidth)
+            throws EncodeException {
+
+        int byteWidth = (int) Math.ceil((float) bitWidth / 8);
+        if (value.size() != byteWidth) {
+            throw new EncodeException(format("Wrong size for %s, expected %d bytes, but found %d",
+                                             entityDescr, byteWidth, value.size()));
+        }
+    }
+
+    static void assertPrefixLen(String entityDescr, int prefixLength, int bitWidth)
+            throws EncodeException {
+
+        if (prefixLength > bitWidth) {
+            throw new EncodeException(format(
+                    "wrong prefix length for %s, field size is %d bits, but found one is %d",
+                    entityDescr, bitWidth, prefixLength));
+        }
+    }
+}