@@ -172,7 +172,7 @@ public void failure(ActionInvocation invocation, UpnpResponse operation, String
     }
 
     protected Service<?, ?> discoverConnectionService(Device<?, ?, ?> device) {
-        if (!device.getType().equals(IGD_DEVICE_TYPE)) {
+        if (!device.getType().implementsVersion(IGD_DEVICE_TYPE)) {
             return null;
         }
 
 
@@ -15,6 +15,8 @@
  */
 package org.jupnp.support.igd.callback;
 
+import java.util.Objects;
+
 import org.jupnp.controlpoint.ActionCallback;
 import org.jupnp.controlpoint.ControlPoint;
 import org.jupnp.model.action.ActionInvocation;
@@ -38,10 +40,10 @@ protected PortMappingAdd(Service<?, ?> service, ControlPoint controlPoint, PortM
 
         this.portMapping = portMapping;
 
-        getActionInvocation().setInput("NewExternalPort", portMapping.getExternalPort());
+        getActionInvocation().setInput("NewExternalPort", Objects.toString(portMapping.getExternalPort(), null));
         getActionInvocation().setInput("NewProtocol", portMapping.getProtocol());
         getActionInvocation().setInput("NewInternalClient", portMapping.getInternalClient());
-        getActionInvocation().setInput("NewInternalPort", portMapping.getInternalPort());
+        getActionInvocation().setInput("NewInternalPort", Objects.toString(portMapping.getInternalPort(), null));
         getActionInvocation().setInput("NewLeaseDuration", portMapping.getLeaseDurationSeconds());
         getActionInvocation().setInput("NewEnabled", portMapping.isEnabled());
         if (portMapping.hasRemoteHost()) {
 
@@ -15,6 +15,8 @@
  */
 package org.jupnp.support.igd.callback;
 
+import java.util.Objects;
+
 import org.jupnp.controlpoint.ActionCallback;
 import org.jupnp.controlpoint.ControlPoint;
 import org.jupnp.model.action.ActionInvocation;
@@ -38,7 +40,7 @@ protected PortMappingDelete(Service<?, ?> service, ControlPoint controlPoint, Po
 
         this.portMapping = portMapping;
 
-        getActionInvocation().setInput("NewExternalPort", portMapping.getExternalPort());
+        getActionInvocation().setInput("NewExternalPort", Objects.toString(portMapping.getExternalPort(), null));
         getActionInvocation().setInput("NewProtocol", portMapping.getProtocol());
         if (portMapping.hasRemoteHost()) {
             getActionInvocation().setInput("NewRemoteHost", portMapping.getRemoteHost());
 
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2011-2026 4th Line GmbH, Switzerland and others
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License Version 1 or later
+ * ("CDDL") (collectively, the "License"). You may not use this file
+ * except in compliance with the License. See LICENSE.txt for more
+ * information.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * SPDX-License-Identifier: CDDL-1.0
+ */
+package org.jupnp.support.igd;
+
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import java.net.InetAddress;
+import java.net.URI;
+import java.net.URL;
+
+import org.junit.jupiter.api.Test;
+import org.jupnp.model.meta.DeviceDetails;
+import org.jupnp.model.meta.RemoteDevice;
+import org.jupnp.model.meta.RemoteDeviceIdentity;
+import org.jupnp.model.meta.RemoteService;
+import org.jupnp.model.meta.Service;
+import org.jupnp.model.types.UDADeviceType;
+import org.jupnp.model.types.UDAServiceId;
+import org.jupnp.model.types.UDAServiceType;
+import org.jupnp.model.types.UDN;
+import org.jupnp.support.model.PortMapping;
+
+class PortMappingListenerTest {
+
+    @Test
+    void discoversVersionTwoInternetGatewayDevice() throws Exception {
+        final RemoteService connectionService = new RemoteService(new UDAServiceType("WANIPConnection", 2),
+                new UDAServiceId("WANIPConnection"), URI.create("service.xml"), URI.create("control"),
+                URI.create("events"));
+        final RemoteDevice connectionDevice = new RemoteDevice(identity("connection"),
+                new UDADeviceType("WANConnectionDevice", 2), new DeviceDetails("WAN connection"),
+                new RemoteService[] { connectionService });
+        final RemoteDevice wanDevice = new RemoteDevice(identity("wan"), new UDADeviceType("WANDevice", 2),
+                new DeviceDetails("WAN device"), new RemoteService[0], new RemoteDevice[] { connectionDevice });
+        final RemoteDevice gateway = new RemoteDevice(identity("gateway"),
+                new UDADeviceType("InternetGatewayDevice", 2), new DeviceDetails("Internet gateway"),
+                new RemoteService[0], new RemoteDevice[] { wanDevice });
+
+        final Service<?, ?> discovered = new PortMappingListener(new PortMapping()).discoverConnectionService(gateway);
+
+        assertSame(connectionService, discovered);
+    }
+
+    private RemoteDeviceIdentity identity(final String name) throws Exception {
+        final URL descriptorUrl = new URL("http://127.0.0.1/" + name + ".xml");
+        final InetAddress localAddress = InetAddress.getLoopbackAddress();
+        return new RemoteDeviceIdentity(new UDN("uuid:" + name), 1800, descriptorUrl, null, localAddress);
+    }
+}
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2011-2026 4th Line GmbH, Switzerland and others
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License Version 1 or later
+ * ("CDDL") (collectively, the "License"). You may not use this file
+ * except in compliance with the License. See LICENSE.txt for more
+ * information.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * SPDX-License-Identifier: CDDL-1.0
+ */
+package org.jupnp.support.igd.callback;
+
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import java.net.URI;
+
+import org.junit.jupiter.api.Test;
+import org.jupnp.model.action.ActionInvocation;
+import org.jupnp.model.message.UpnpResponse;
+import org.jupnp.model.meta.Action;
+import org.jupnp.model.meta.ActionArgument;
+import org.jupnp.model.meta.RemoteService;
+import org.jupnp.model.meta.StateVariable;
+import org.jupnp.model.meta.StateVariableTypeDetails;
+import org.jupnp.model.types.Datatype;
+import org.jupnp.model.types.UDAServiceId;
+import org.jupnp.model.types.UDAServiceType;
+import org.jupnp.model.types.UnsignedIntegerFourBytes;
+import org.jupnp.support.model.PortMapping;
+
+class PortMappingCallbackTest {
+
+    @Test
+    void addUsesPortDatatypeAdvertisedByTheService() throws Exception {
+        final PortMappingAdd callback = new PortMappingAdd(portMappingService(Datatype.Builtin.UI4.getDatatype(), true),
+                mapping()) {
+            @Override
+            public void success(final ActionInvocation invocation) {
+            }
+
+            @Override
+            public void failure(final ActionInvocation invocation, final UpnpResponse operation,
+                    final String defaultMsg) {
+            }
+        };
+        final ActionInvocation<?> invocation = callback.getActionInvocation();
+
+        assertInstanceOf(UnsignedIntegerFourBytes.class, invocation.getInput("NewExternalPort").getValue());
+        assertInstanceOf(UnsignedIntegerFourBytes.class, invocation.getInput("NewInternalPort").getValue());
+    }
+
+    @Test
+    void deleteUsesPortDatatypeAdvertisedByTheService() throws Exception {
+        final PortMappingDelete callback = new PortMappingDelete(
+                portMappingService(Datatype.Builtin.UI4.getDatatype(), false), mapping()) {
+            @Override
+            public void success(final ActionInvocation invocation) {
+            }
+
+            @Override
+            public void failure(final ActionInvocation invocation, final UpnpResponse operation,
+                    final String defaultMsg) {
+            }
+        };
+        final ActionInvocation<?> invocation = callback.getActionInvocation();
+
+        assertInstanceOf(UnsignedIntegerFourBytes.class, invocation.getInput("NewExternalPort").getValue());
+    }
+
+    @Test
+    void addAllowsUnsetPorts() throws Exception {
+        final PortMappingAdd callback = new PortMappingAdd(portMappingService(Datatype.Builtin.UI4.getDatatype(), true),
+                new PortMapping()) {
+            @Override
+            public void success(final ActionInvocation invocation) {
+            }
+
+            @Override
+            public void failure(final ActionInvocation invocation, final UpnpResponse operation,
+                    final String defaultMsg) {
+            }
+        };
+        final ActionInvocation<?> invocation = callback.getActionInvocation();
+
+        assertNull(invocation.getInput("NewExternalPort").getValue());
+        assertNull(invocation.getInput("NewInternalPort").getValue());
+    }
+
+    private PortMapping mapping() {
+        return new PortMapping(36743, "192.168.1.99", PortMapping.Protocol.TCP, "jUPnP test");
+    }
+
+    private RemoteService portMappingService(final Datatype<?> portDatatype, final boolean add) throws Exception {
+        final StateVariable[] variables = new StateVariable[] { variable("ExternalPort", portDatatype),
+                variable("InternalPort", portDatatype), variable("Protocol", Datatype.Builtin.STRING.getDatatype()),
+                variable("InternalClient", Datatype.Builtin.STRING.getDatatype()),
+                variable("LeaseDuration", Datatype.Builtin.UI4.getDatatype()),
+                variable("Enabled", Datatype.Builtin.BOOLEAN.getDatatype()),
+                variable("Description", Datatype.Builtin.STRING.getDatatype()) };
+        final Action action = add
+                ? new Action("AddPortMapping",
+                        new ActionArgument[] { input("NewExternalPort", "ExternalPort"),
+                                input("NewProtocol", "Protocol"), input("NewInternalClient", "InternalClient"),
+                                input("NewInternalPort", "InternalPort"), input("NewLeaseDuration", "LeaseDuration"),
+                                input("NewEnabled", "Enabled"), input("NewPortMappingDescription", "Description") })
+                : new Action("DeletePortMapping", new ActionArgument[] { input("NewExternalPort", "ExternalPort"),
+                        input("NewProtocol", "Protocol") });
+
+        return new RemoteService(new UDAServiceType("WANIPConnection", 1), new UDAServiceId("WANIPConnection"),
+                URI.create("service.xml"), URI.create("control"), URI.create("events"), new Action[] { action },
+                variables);
+    }
+
+    private StateVariable variable(final String name, final Datatype<?> datatype) {
+        return new StateVariable(name, new StateVariableTypeDetails(datatype));
+    }
+
+    private ActionArgument input(final String name, final String stateVariable) {
+        return new ActionArgument(name, stateVariable, ActionArgument.Direction.IN);
+    }
+}
Original file line number	Diff line number	Diff line change
`@@ -172,7 +172,7 @@ public void failure(ActionInvocation invocation, UpnpResponse operation, String`
`172`	`172`	`}`
`173`	`173`
`174`	`174`	`protected Service<?, ?> discoverConnectionService(Device<?, ?, ?> device) {`
`175`		`- if (!device.getType().equals(IGD_DEVICE_TYPE)) {`
	`175`	`+ if (!device.getType().implementsVersion(IGD_DEVICE_TYPE)) {`
`176`	`176`	`return null;`
`177`	`177`	`}`
`178`	`178`