diff --git a/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
index 3970e76..43a5bdf 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
@@ -195,6 +195,18 @@
         }
 
         /**
+         * Adds an exact field match for the given fieldId and value.
+         *
+         * @param fieldId protocol-independent header field Id
+         * @param value   exact match value
+         * @return this
+         */
+        public Builder matchExact(PiMatchFieldId fieldId, String value) {
+            fieldMatchMapBuilder.put(fieldId, new PiExactFieldMatch(fieldId, copyFrom(value)));
+            return this;
+        }
+
+        /**
          * Adds a ternary field match for the given fieldId, value and mask.
          *
          * @param fieldId protocol-independent header field Id
@@ -399,6 +411,18 @@
         }
 
         /**
+         * Adds an optional field match for the given fieldId and value.
+         *
+         * @param fieldId protocol-independent header field Id
+         * @param value   optional match value
+         * @return this
+         */
+        public Builder matchOptional(PiMatchFieldId fieldId, String value) {
+            fieldMatchMapBuilder.put(fieldId, new PiOptionalFieldMatch(fieldId, copyFrom(value)));
+            return this;
+        }
+
+        /**
          * Builds a PiCriterion.
          *
          * @return PiCriterion
diff --git a/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionParam.java b/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionParam.java
index a8d565c..91f6e04 100644
--- a/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionParam.java
+++ b/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionParam.java
@@ -104,6 +104,17 @@
     }
 
     /**
+     * Creates an action's runtime parameter for the given param ID and string
+     * value.
+     *
+     * @param id    parameter identifier
+     * @param value value
+     */
+    public PiActionParam(PiActionParamId id, String value) {
+        this(id, copyFrom(value));
+    }
+
+    /**
      * Returns the identifier of this parameter.
      *
      * @return parameter identifier
diff --git a/protocols/p4runtime/ctl/src/test/java/org/onosproject/p4runtime/ctl/codec/TableEntryEncoderTest.java b/protocols/p4runtime/ctl/src/test/java/org/onosproject/p4runtime/ctl/codec/TableEntryEncoderTest.java
index 8614527..29f2936 100644
--- a/protocols/p4runtime/ctl/src/test/java/org/onosproject/p4runtime/ctl/codec/TableEntryEncoderTest.java
+++ b/protocols/p4runtime/ctl/src/test/java/org/onosproject/p4runtime/ctl/codec/TableEntryEncoderTest.java
@@ -100,10 +100,10 @@
     private final P4InfoBrowser browser2 = PipeconfHelper.getP4InfoBrowser(defaultPipeconf2);
     private final ImmutableByteSequence ethAddr = copyFrom(rand.nextInt()).fit(48);
     private final ImmutableByteSequence ethAddrString = ImmutableByteSequence.copyFrom(
-            "00:11:22:33:44:55:66".getBytes());
+            "00:11:22:33:44:55:66");
     private final ImmutableByteSequence portValue = copyFrom((short) rand.nextInt());
     private final ImmutableByteSequence portValueString = ImmutableByteSequence.copyFrom(
-            String.format("Ethernet%d", rand.nextInt()).getBytes());
+            String.format("Ethernet%d", rand.nextInt()));
     private final ImmutableByteSequence portValue32Bit = copyFrom((short) rand.nextInt()).fit(32);
     private final PiMatchFieldId ethDstAddrFieldId = PiMatchFieldId.of(HDR + DOT + ETHERNET + DOT + DST_ADDR);
     private final PiMatchFieldId ethSrcAddrFieldId = PiMatchFieldId.of(HDR + DOT + ETHERNET + DOT + SRC_ADDR);
diff --git a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/ActionCodec.java b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/ActionCodec.java
index 69b31a8..d0a285e 100644
--- a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/ActionCodec.java
+++ b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/ActionCodec.java
@@ -74,10 +74,14 @@
         final PiAction.Builder builder = PiAction.builder()
                 .withId(PiActionId.of(actionName));
         for (P4RuntimeOuterClass.Action.Param p : message.getParamsList()) {
-            final String paramName = paramInfo.getById(p.getParamId()).getName();
-            final ImmutableByteSequence value = ImmutableByteSequence.copyFrom(
-                    p.getValue().toByteArray());
-            builder.withParameter(new PiActionParam(PiActionParamId.of(paramName), value));
+            final P4InfoOuterClass.Action.Param actionParam = paramInfo.getById(p.getParamId());
+            final ImmutableByteSequence value;
+            if (browser.isTypeString(actionParam.getTypeName())) {
+                value = ImmutableByteSequence.copyFrom(new String(p.getValue().toByteArray()));
+            } else {
+                value = ImmutableByteSequence.copyFrom(p.getValue().toByteArray());
+            }
+            builder.withParameter(new PiActionParam(PiActionParamId.of(actionParam.getName()), value));
         }
         return builder.build();
     }
diff --git a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/FieldMatchCodec.java b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/FieldMatchCodec.java
index d42e6b9..6b01546 100644
--- a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/FieldMatchCodec.java
+++ b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/FieldMatchCodec.java
@@ -152,16 +152,23 @@
             PiPipeconf pipeconf, P4InfoBrowser browser)
             throws CodecException, P4InfoBrowser.NotFoundException {
 
-        String fieldMatchName = browser.matchFields(tablePreamble.getId())
-                .getById(message.getFieldId()).getName();
-        PiMatchFieldId headerFieldId = PiMatchFieldId.of(fieldMatchName);
+        final P4InfoOuterClass.MatchField matchField =
+                browser.matchFields(tablePreamble.getId())
+                        .getById(message.getFieldId());
+        final PiMatchFieldId headerFieldId = PiMatchFieldId.of(matchField.getName());
+        final boolean isSdnString = browser.isTypeString(matchField.getTypeName());
 
         P4RuntimeOuterClass.FieldMatch.FieldMatchTypeCase typeCase = message.getFieldMatchTypeCase();
 
         switch (typeCase) {
             case EXACT:
                 P4RuntimeOuterClass.FieldMatch.Exact exactFieldMatch = message.getExact();
-                ImmutableByteSequence exactValue = copyFrom(exactFieldMatch.getValue().asReadOnlyByteBuffer());
+                ImmutableByteSequence exactValue;
+                if (isSdnString) {
+                    exactValue = copyFrom(new String(exactFieldMatch.getValue().toByteArray()));
+                } else {
+                    exactValue = copyFrom(exactFieldMatch.getValue().asReadOnlyByteBuffer());
+                }
                 return new PiExactFieldMatch(headerFieldId, exactValue);
             case TERNARY:
                 P4RuntimeOuterClass.FieldMatch.Ternary ternaryFieldMatch = message.getTernary();
@@ -180,7 +187,12 @@
                 return new PiRangeFieldMatch(headerFieldId, rangeLowValue, rangeHighValue);
             case OPTIONAL:
                 P4RuntimeOuterClass.FieldMatch.Optional optionalFieldMatch = message.getOptional();
-                ImmutableByteSequence optionalValue = copyFrom(optionalFieldMatch.getValue().asReadOnlyByteBuffer());
+                ImmutableByteSequence optionalValue;
+                if (isSdnString) {
+                    optionalValue = copyFrom(new String(optionalFieldMatch.getValue().toByteArray()));
+                } else {
+                    optionalValue = copyFrom(optionalFieldMatch.getValue().asReadOnlyByteBuffer());
+                }
                 return new PiOptionalFieldMatch(headerFieldId, optionalValue);
             default:
                 throw new CodecException(format(
diff --git a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/PacketMetadataCodec.java b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/PacketMetadataCodec.java
index 3f78085..876f84c 100644
--- a/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/PacketMetadataCodec.java
+++ b/protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/PacketMetadataCodec.java
@@ -17,6 +17,7 @@
 package org.onosproject.p4runtime.ctl.codec;
 
 import com.google.protobuf.ByteString;
+import org.onlab.util.ImmutableByteSequence;
 import org.onosproject.net.pi.model.PiPacketMetadataId;
 import org.onosproject.net.pi.model.PiPipeconf;
 import org.onosproject.net.pi.runtime.PiPacketMetadata;
@@ -54,14 +55,18 @@
             P4InfoOuterClass.Preamble ctrlPktMetaPreamble,
             PiPipeconf pipeconf, P4InfoBrowser browser)
             throws P4InfoBrowser.NotFoundException {
-        final String packetMetadataName = browser
-                .packetMetadatas(ctrlPktMetaPreamble.getId())
-                .getById(message.getMetadataId()).getName();
-        final PiPacketMetadataId metadataId = PiPacketMetadataId
-                .of(packetMetadataName);
+        final P4InfoOuterClass.ControllerPacketMetadata.Metadata packetMetadata =
+                browser.packetMetadatas(ctrlPktMetaPreamble.getId())
+                .getById(message.getMetadataId());
+        final ImmutableByteSequence value;
+        if (browser.isTypeString(packetMetadata.getTypeName())) {
+            value = copyFrom(new String(message.getValue().toByteArray()));
+        } else {
+            value = copyFrom(message.getValue().asReadOnlyByteBuffer());
+        }
         return PiPacketMetadata.builder()
-                .withId(metadataId)
-                .withValue(copyFrom(message.getValue().asReadOnlyByteBuffer()))
+                .withId(PiPacketMetadataId.of(packetMetadata.getName()))
+                .withValue(value)
                 .build();
     }
 }
diff --git a/utils/misc/src/main/java/org/onlab/util/ImmutableByteSequence.java b/utils/misc/src/main/java/org/onlab/util/ImmutableByteSequence.java
index 013f3c5..1710d29 100644
--- a/utils/misc/src/main/java/org/onlab/util/ImmutableByteSequence.java
+++ b/utils/misc/src/main/java/org/onlab/util/ImmutableByteSequence.java
@@ -51,6 +51,7 @@
     The order of a newly-created byte buffer is always BIG_ENDIAN.
      */
     private ByteBuffer value;
+    private boolean isAscii = false;
 
     /**
      * Private constructor. Creates a new byte sequence object backed by the
@@ -65,6 +66,11 @@
         this.value.rewind();
     }
 
+    private ImmutableByteSequence(ByteBuffer value, boolean isAscii) {
+        this(value);
+        this.isAscii = isAscii;
+    }
+
     /**
      * Creates a new immutable byte sequence with the same content and order of
      * the passed byte array.
@@ -126,6 +132,20 @@
     }
 
     /**
+     * Creates a new immutable byte sequence from the given string.
+     *
+     * @param original a string
+     * @return a new byte buffer object
+     */
+    public static ImmutableByteSequence copyFrom(String original) {
+        checkArgument(original != null && original.length() > 0,
+                      "Cannot copy from an empty or null string");
+        return new ImmutableByteSequence(ByteBuffer.allocate(original.length())
+                                                 .put(original.getBytes()),
+                                         true);
+    }
+
+    /**
      * Creates a new byte sequence of 8 bytes containing the given long value.
      *
      * @param original a long value
@@ -394,19 +414,34 @@
     }
 
     /**
-     * Returns a hexadecimal representation of this byte sequence, e.g.
-     * 0xbeef. The length of the returned string is not representative of the
-     * length of the byte sequence, as all padding zeros are removed.
+     * Returns the ASCII representation of the byte sequence if the content can
+     * be interpreted as an ASCII string, otherwise returns the hexadecimal
+     * representation of this byte sequence, e.g.0xbeef. The length of the
+     * returned string is not representative of the length of the byte sequence,
+     * as all padding zeros are removed.
      *
      * @return hexadecimal representation
      */
     @Override
     public String toString() {
-        final String hexValue = HexString
-                .toHexString(value.array(), "")
-                // Remove leading zeros, but leave one if string is all zeros.
-                .replaceFirst("^0+(?!$)", "");
-        return "0x" + hexValue;
+        if (this.isAscii()) {
+            return new String(value.array());
+        } else {
+            return "0x" + HexString
+                    .toHexString(value.array(), "")
+                    // Remove leading zeros, but leave one if string is all zeros.
+                    .replaceFirst("^0+(?!$)", "");
+        }
+    }
+
+    /**
+     * Checks if the content can be interpreted as an ASCII printable string.
+     *
+     * @return True if the content can be interpreted as an ASCII printable
+     *  string, false otherwise
+     */
+    public boolean isAscii() {
+        return isAscii;
     }
 
     /**