diff --git a/core/java/android/net/vcn/VcnTransportInfo.java b/core/java/android/net/vcn/VcnTransportInfo.java
index f546910..1fc91ee 100644
--- a/core/java/android/net/vcn/VcnTransportInfo.java
+++ b/core/java/android/net/vcn/VcnTransportInfo.java
@@ -17,9 +17,11 @@
 package android.net.vcn;
 
 import static android.net.NetworkCapabilities.REDACT_FOR_NETWORK_SETTINGS;
+import static android.net.vcn.VcnGatewayConnectionConfig.MIN_UDP_PORT_4500_NAT_TIMEOUT_SECONDS;
 import static android.net.vcn.VcnGatewayConnectionConfig.MIN_UDP_PORT_4500_NAT_TIMEOUT_UNSET;
 import static android.telephony.SubscriptionManager.INVALID_SUBSCRIPTION_ID;
 
+import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.net.NetworkCapabilities;
@@ -29,6 +31,8 @@
 import android.os.Parcelable;
 import android.telephony.SubscriptionManager;
 
+import com.android.internal.util.Preconditions;
+
 import java.util.Objects;
 
 /**
@@ -47,6 +51,7 @@
  *
  * @hide
  */
+// TODO: Do not store WifiInfo and subscription ID in VcnTransportInfo anymore
 public class VcnTransportInfo implements TransportInfo, Parcelable {
     @Nullable private final WifiInfo mWifiInfo;
     private final int mSubId;
@@ -195,4 +200,42 @@
                     return new VcnTransportInfo[size];
                 }
             };
+
+    /** This class can be used to construct a {@link VcnTransportInfo}. */
+    public static final class Builder {
+        private int mMinUdpPort4500NatTimeoutSeconds = MIN_UDP_PORT_4500_NAT_TIMEOUT_UNSET;
+
+        /** Construct Builder */
+        public Builder() {}
+
+        /**
+         * Sets the maximum supported IKEv2/IPsec NATT keepalive timeout.
+         *
+         * <p>This is used as a power-optimization hint for other IKEv2/IPsec use cases (e.g. VPNs,
+         * or IWLAN) to reduce the necessary keepalive frequency, thus conserving power and data.
+         *
+         * @param minUdpPort4500NatTimeoutSeconds the maximum keepalive timeout supported by the VCN
+         *     Gateway Connection, generally the minimum duration a NAT mapping is cached on the VCN
+         *     Gateway.
+         * @return this {@link Builder} instance, for chaining
+         */
+        @NonNull
+        public Builder setMinUdpPort4500NatTimeoutSeconds(
+                @IntRange(from = MIN_UDP_PORT_4500_NAT_TIMEOUT_SECONDS)
+                        int minUdpPort4500NatTimeoutSeconds) {
+            Preconditions.checkArgument(
+                    minUdpPort4500NatTimeoutSeconds >= MIN_UDP_PORT_4500_NAT_TIMEOUT_SECONDS,
+                    "Timeout must be at least 120s");
+
+            mMinUdpPort4500NatTimeoutSeconds = minUdpPort4500NatTimeoutSeconds;
+            return Builder.this;
+        }
+
+        /** Build a VcnTransportInfo instance */
+        @NonNull
+        public VcnTransportInfo build() {
+            return new VcnTransportInfo(
+                    null /* wifiInfo */, INVALID_SUBSCRIPTION_ID, mMinUdpPort4500NatTimeoutSeconds);
+        }
+    }
 }
diff --git a/core/java/android/net/vcn/VcnUtils.java b/core/java/android/net/vcn/VcnUtils.java
new file mode 100644
index 0000000..6dc5180
--- /dev/null
+++ b/core/java/android/net/vcn/VcnUtils.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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 android.net.vcn;
+
+import static android.telephony.SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkSpecifier;
+import android.net.TelephonyNetworkSpecifier;
+import android.net.TransportInfo;
+import android.net.wifi.WifiInfo;
+
+import java.util.List;
+
+/**
+ * Utility class for VCN callers get information from VCN network
+ *
+ * @hide
+ */
+public class VcnUtils {
+    /** Get the WifiInfo of the VCN's underlying WiFi network */
+    @Nullable
+    public static WifiInfo getWifiInfoFromVcnCaps(
+            @NonNull ConnectivityManager connectivityMgr,
+            @NonNull NetworkCapabilities networkCapabilities) {
+        final NetworkCapabilities underlyingCaps =
+                getVcnUnderlyingCaps(connectivityMgr, networkCapabilities);
+
+        if (underlyingCaps == null) {
+            return null;
+        }
+
+        final TransportInfo underlyingTransportInfo = underlyingCaps.getTransportInfo();
+        if (!(underlyingTransportInfo instanceof WifiInfo)) {
+            return null;
+        }
+
+        return (WifiInfo) underlyingTransportInfo;
+    }
+
+    /** Get the subscription ID of the VCN's underlying Cell network */
+    public static int getSubIdFromVcnCaps(
+            @NonNull ConnectivityManager connectivityMgr,
+            @NonNull NetworkCapabilities networkCapabilities) {
+        final NetworkCapabilities underlyingCaps =
+                getVcnUnderlyingCaps(connectivityMgr, networkCapabilities);
+
+        if (underlyingCaps == null) {
+            return INVALID_SUBSCRIPTION_ID;
+        }
+
+        final NetworkSpecifier underlyingNetworkSpecifier = underlyingCaps.getNetworkSpecifier();
+        if (!(underlyingNetworkSpecifier instanceof TelephonyNetworkSpecifier)) {
+            return INVALID_SUBSCRIPTION_ID;
+        }
+
+        return ((TelephonyNetworkSpecifier) underlyingNetworkSpecifier).getSubscriptionId();
+    }
+
+    @Nullable
+    private static NetworkCapabilities getVcnUnderlyingCaps(
+            @NonNull ConnectivityManager connectivityMgr,
+            @NonNull NetworkCapabilities networkCapabilities) {
+        // Return null if it is not a VCN network
+        if (networkCapabilities.getTransportInfo() == null
+                || !(networkCapabilities.getTransportInfo() instanceof VcnTransportInfo)) {
+            return null;
+        }
+
+        // As of Android 16, VCN has one underlying network, and only one. If there are more
+        // than one networks due to future changes in the VCN mainline code, just take the first
+        // network
+        final List<Network> underlyingNws = networkCapabilities.getUnderlyingNetworks();
+        if (underlyingNws == null) {
+            return null;
+        }
+
+        return connectivityMgr.getNetworkCapabilities(underlyingNws.get(0));
+    }
+}
diff --git a/tests/vcn/java/android/net/vcn/VcnTransportInfoTest.java b/tests/vcn/java/android/net/vcn/VcnTransportInfoTest.java
index 81814b6..7bc9970 100644
--- a/tests/vcn/java/android/net/vcn/VcnTransportInfoTest.java
+++ b/tests/vcn/java/android/net/vcn/VcnTransportInfoTest.java
@@ -25,6 +25,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
 
 import android.net.NetworkCapabilities;
 import android.net.wifi.WifiConfiguration;
@@ -39,6 +40,7 @@
     private static final int SUB_ID = 1;
     private static final int NETWORK_ID = 5;
     private static final int MIN_UDP_PORT_4500_NAT_TIMEOUT = 120;
+    private static final int MIN_UDP_PORT_4500_NAT_TIMEOUT_INVALID = 119;
     private static final WifiInfo WIFI_INFO =
             new WifiInfo.Builder().setNetworkId(NETWORK_ID).build();
 
@@ -48,6 +50,27 @@
             new VcnTransportInfo(WIFI_INFO, MIN_UDP_PORT_4500_NAT_TIMEOUT);
 
     @Test
+    public void testBuilder() {
+        final VcnTransportInfo transportInfo =
+                new VcnTransportInfo.Builder()
+                        .setMinUdpPort4500NatTimeoutSeconds(MIN_UDP_PORT_4500_NAT_TIMEOUT)
+                        .build();
+
+        assertEquals(
+                MIN_UDP_PORT_4500_NAT_TIMEOUT, transportInfo.getMinUdpPort4500NatTimeoutSeconds());
+    }
+
+    @Test
+    public void testBuilder_withInvalidNatTimeout() {
+        try {
+            new VcnTransportInfo.Builder()
+                    .setMinUdpPort4500NatTimeoutSeconds(MIN_UDP_PORT_4500_NAT_TIMEOUT_INVALID);
+            fail("Expected to fail due to invalid NAT timeout");
+        } catch (Exception expected) {
+        }
+    }
+
+    @Test
     public void testGetWifiInfo() {
         assertEquals(WIFI_INFO, WIFI_UNDERLYING_INFO.getWifiInfo());
 
diff --git a/tests/vcn/java/android/net/vcn/VcnUtilsTest.java b/tests/vcn/java/android/net/vcn/VcnUtilsTest.java
new file mode 100644
index 0000000..3ce6c8f
--- /dev/null
+++ b/tests/vcn/java/android/net/vcn/VcnUtilsTest.java
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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 android.net.vcn;
+
+import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
+import static android.telephony.SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.TelephonyNetworkSpecifier;
+import android.net.wifi.WifiInfo;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+
+public class VcnUtilsTest {
+    private static final int SUB_ID = 1;
+
+    private static final WifiInfo WIFI_INFO = new WifiInfo.Builder().build();
+    private static final TelephonyNetworkSpecifier TEL_NETWORK_SPECIFIER =
+            new TelephonyNetworkSpecifier.Builder().setSubscriptionId(SUB_ID).build();
+    private static final VcnTransportInfo VCN_TRANSPORT_INFO =
+            new VcnTransportInfo.Builder().build();
+
+    private ConnectivityManager mMockConnectivityManager;
+    private Network mMockWifiNetwork;
+    private Network mMockCellNetwork;
+
+    private NetworkCapabilities mVcnCapsWithUnderlyingWifi;
+    private NetworkCapabilities mVcnCapsWithUnderlyingCell;
+
+    @Before
+    public void setUp() {
+        mMockConnectivityManager = mock(ConnectivityManager.class);
+
+        mMockWifiNetwork = mock(Network.class);
+        mVcnCapsWithUnderlyingWifi = newVcnCaps(VCN_TRANSPORT_INFO, mMockWifiNetwork);
+        final NetworkCapabilities wifiCaps =
+                new NetworkCapabilities.Builder()
+                        .addTransportType(TRANSPORT_WIFI)
+                        .setTransportInfo(WIFI_INFO)
+                        .build();
+        when(mMockConnectivityManager.getNetworkCapabilities(mMockWifiNetwork))
+                .thenReturn(wifiCaps);
+
+        mMockCellNetwork = mock(Network.class);
+        mVcnCapsWithUnderlyingCell = newVcnCaps(VCN_TRANSPORT_INFO, mMockCellNetwork);
+        final NetworkCapabilities cellCaps =
+                new NetworkCapabilities.Builder()
+                        .addTransportType(TRANSPORT_CELLULAR)
+                        .setNetworkSpecifier(TEL_NETWORK_SPECIFIER)
+                        .build();
+        when(mMockConnectivityManager.getNetworkCapabilities(mMockCellNetwork))
+                .thenReturn(cellCaps);
+    }
+
+    private static NetworkCapabilities newVcnCaps(
+            VcnTransportInfo vcnTransportInfo, Network underlyingNetwork) {
+        return new NetworkCapabilities.Builder()
+                .setTransportInfo(vcnTransportInfo)
+                .setUnderlyingNetworks(Collections.singletonList(underlyingNetwork))
+                .build();
+    }
+
+    @Test
+    public void getWifiInfoFromVcnCaps() {
+        assertEquals(
+                WIFI_INFO,
+                VcnUtils.getWifiInfoFromVcnCaps(
+                        mMockConnectivityManager, mVcnCapsWithUnderlyingWifi));
+    }
+
+    @Test
+    public void getWifiInfoFromVcnCaps_onVcnWithUnderlyingCell() {
+        assertNull(
+                VcnUtils.getWifiInfoFromVcnCaps(
+                        mMockConnectivityManager, mVcnCapsWithUnderlyingCell));
+    }
+
+    @Test
+    public void getSubIdFromVcnCaps() {
+        assertEquals(
+                SUB_ID,
+                VcnUtils.getSubIdFromVcnCaps(mMockConnectivityManager, mVcnCapsWithUnderlyingCell));
+    }
+
+    @Test
+    public void getSubIdFromVcnCaps_onVcnWithUnderlyingWifi() {
+        assertEquals(
+                INVALID_SUBSCRIPTION_ID,
+                VcnUtils.getSubIdFromVcnCaps(mMockConnectivityManager, mVcnCapsWithUnderlyingWifi));
+    }
+
+    @Test
+    public void getSubIdFromVcnCaps_onNonVcnNetwork() {
+        assertEquals(
+                INVALID_SUBSCRIPTION_ID,
+                VcnUtils.getSubIdFromVcnCaps(
+                        mMockConnectivityManager, new NetworkCapabilities.Builder().build()));
+    }
+
+    @Test
+    public void getSubIdFromVcnCaps_withMultipleUnderlyingNetworks() {
+        final NetworkCapabilities vcnCaps =
+                new NetworkCapabilities.Builder(mVcnCapsWithUnderlyingCell)
+                        .setUnderlyingNetworks(
+                                Arrays.asList(
+                                        new Network[] {mMockCellNetwork, mock(Network.class)}))
+                        .build();
+        assertEquals(SUB_ID, VcnUtils.getSubIdFromVcnCaps(mMockConnectivityManager, vcnCaps));
+    }
+}