Changed the way ProviderId is made to include URI scheme portion.
diff --git a/core/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderRegistry.java b/core/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderRegistry.java
index f8cdb6b..6cf91a6 100644
--- a/core/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderRegistry.java
+++ b/core/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderRegistry.java
@@ -1,6 +1,7 @@
 package org.onlab.onos.net.provider;
 
 import com.google.common.collect.ImmutableSet;
+import org.onlab.onos.net.DeviceId;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -20,6 +21,7 @@
 
     private final Map<ProviderId, P> providers = new HashMap<>();
     private final Map<ProviderId, S> services = new HashMap<>();
+    private final Map<String, P> providersByScheme = new HashMap<>();
 
     /**
      * Creates a new provider service bound to the specified provider.
@@ -65,4 +67,14 @@
         return providers.get(providerId);
     }
 
+    /**
+     * Returns the provider for the specified device ID based on URI scheme.
+     *
+     * @param deviceId device identifier
+     * @return provider bound to the URI scheme
+     */
+    protected synchronized P getProvider(DeviceId deviceId) {
+        return providersByScheme.get(deviceId.uri().getScheme());
+    }
+
 }
diff --git a/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java b/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
index a945354..e9af0eb 100644
--- a/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
+++ b/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
@@ -9,6 +9,7 @@
  */
 public class ProviderId {
 
+    private final String scheme;
     private final String id;
 
     /**
@@ -16,15 +17,26 @@
      * The providers are expected to follow the reverse DNS convention, e.g.
      * {@code org.onlab.onos.provider.of.device}
      *
-     * @param id string identifier
+     * @param scheme device URI scheme to which this provider is bound, e.g. "of", "snmp"
+     * @param id     string identifier
      */
-    public ProviderId(String id) {
+    public ProviderId(String scheme, String id) {
+        this.scheme = scheme;
         this.id = id;
     }
 
+    /**
+     * Returns the device URI scheme to which this provider is bound.
+     *
+     * @return device URI scheme
+     */
+    public String scheme() {
+        return scheme;
+    }
+
     @Override
     public int hashCode() {
-        return Objects.hash(id);
+        return Objects.hash(scheme, id);
     }
 
     @Override
@@ -36,12 +48,13 @@
             return false;
         }
         final ProviderId other = (ProviderId) obj;
-        return Objects.equals(this.id, other.id);
+        return Objects.equals(this.scheme, other.scheme) &&
+                Objects.equals(this.id, other.id);
     }
 
     @Override
     public String toString() {
-        return toStringHelper(this).add("id", id).toString();
+        return toStringHelper(this).add("scheme", scheme).add("id", id).toString();
     }
 
 }
diff --git a/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java b/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
index c37a15c..ea1c8fd 100644
--- a/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
@@ -13,7 +13,7 @@
  */
 public class DefaultDeviceTest {
 
-    private static final ProviderId PID = new ProviderId("foo");
+    private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final DeviceId DID2 = deviceId("of:bar");
     private static final String MFR = "whitebox";
diff --git a/core/api/src/test/java/org/onlab/onos/net/DefaultEdgeLinkTest.java b/core/api/src/test/java/org/onlab/onos/net/DefaultEdgeLinkTest.java
index a19f969..b3891f1 100644
--- a/core/api/src/test/java/org/onlab/onos/net/DefaultEdgeLinkTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/DefaultEdgeLinkTest.java
@@ -15,7 +15,7 @@
  */
 public class DefaultEdgeLinkTest {
 
-    private static final ProviderId PID = new ProviderId("foo");
+    private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final HostId HID1 = hostId("nic:foobar");
     private static final HostId HID2 = hostId("nic:barfoo");
diff --git a/core/api/src/test/java/org/onlab/onos/net/DefaultLinkTest.java b/core/api/src/test/java/org/onlab/onos/net/DefaultLinkTest.java
index ec8511e..a62c822 100644
--- a/core/api/src/test/java/org/onlab/onos/net/DefaultLinkTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/DefaultLinkTest.java
@@ -15,7 +15,7 @@
  */
 public class DefaultLinkTest {
 
-    private static final ProviderId PID = new ProviderId("foo");
+    private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final DeviceId DID2 = deviceId("of:bar");
     private static final PortNumber P1 = portNumber(1);
diff --git a/core/api/src/test/java/org/onlab/onos/net/DefaultPortTest.java b/core/api/src/test/java/org/onlab/onos/net/DefaultPortTest.java
index e9d3da6..1069fd1 100644
--- a/core/api/src/test/java/org/onlab/onos/net/DefaultPortTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/DefaultPortTest.java
@@ -14,7 +14,7 @@
  */
 public class DefaultPortTest {
 
-    private static final ProviderId PID = new ProviderId("foo");
+    private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final DeviceId DID2 = deviceId("of:bar");
     private static final PortNumber P1 = portNumber(1);
diff --git a/core/api/src/test/java/org/onlab/onos/net/TestDeviceParams.java b/core/api/src/test/java/org/onlab/onos/net/TestDeviceParams.java
index afaf23e..7471a2d 100644
--- a/core/api/src/test/java/org/onlab/onos/net/TestDeviceParams.java
+++ b/core/api/src/test/java/org/onlab/onos/net/TestDeviceParams.java
@@ -17,7 +17,7 @@
  */
 public abstract class TestDeviceParams {
 
-    protected static final ProviderId PID = new ProviderId("foo");
+    protected static final ProviderId PID = new ProviderId("of", "foo");
     protected static final DeviceId DID1 = deviceId("of:foo");
     protected static final DeviceId DID2 = deviceId("of:bar");
     protected static final MacAddress MAC1 = MacAddress.valueOf("00:11:00:00:00:01");
diff --git a/core/api/src/test/java/org/onlab/onos/net/device/DeviceEventTest.java b/core/api/src/test/java/org/onlab/onos/net/device/DeviceEventTest.java
index 7175308..df19365 100644
--- a/core/api/src/test/java/org/onlab/onos/net/device/DeviceEventTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/device/DeviceEventTest.java
@@ -18,7 +18,7 @@
 public class DeviceEventTest extends AbstractEventTest {
 
     private Device createDevice() {
-        return new DefaultDevice(new ProviderId("foo"), deviceId("of:foo"),
+        return new DefaultDevice(new ProviderId("of", "foo"), deviceId("of:foo"),
                 Device.Type.SWITCH, "box", "hw", "sw", "sn");
     }
 
diff --git a/core/api/src/test/java/org/onlab/onos/net/host/HostEventTest.java b/core/api/src/test/java/org/onlab/onos/net/host/HostEventTest.java
index a0d6848..561b041 100644
--- a/core/api/src/test/java/org/onlab/onos/net/host/HostEventTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/host/HostEventTest.java
@@ -34,7 +34,7 @@
         HostId hid = HostId.hostId(mac, vlan);
 
         return new DefaultHost(
-                new ProviderId("foo"), hid, mac, vlan, loc, ipset);
+                new ProviderId("of", "foo"), hid, mac, vlan, loc, ipset);
     }
 
     @Override
diff --git a/core/api/src/test/java/org/onlab/onos/net/link/LinkEventTest.java b/core/api/src/test/java/org/onlab/onos/net/link/LinkEventTest.java
index dae9f85..aa95a42 100644
--- a/core/api/src/test/java/org/onlab/onos/net/link/LinkEventTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/link/LinkEventTest.java
@@ -16,7 +16,7 @@
 public class LinkEventTest extends AbstractEventTest {
 
     private Link createLink() {
-        return new DefaultLink(new ProviderId("foo"),
+        return new DefaultLink(new ProviderId("of", "foo"),
                                new ConnectPoint(deviceId("of:foo"), portNumber(1)),
                                new ConnectPoint(deviceId("of:bar"), portNumber(2)),
                                Link.Type.INDIRECT);
diff --git a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
index abbe5be..37bee71 100644
--- a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
@@ -28,14 +28,14 @@
         TestProviderRegistry registry = new TestProviderRegistry();
         assertEquals("incorrect provider count", 0, registry.getProviders().size());
 
-        ProviderId fooId = new ProviderId("foo");
+        ProviderId fooId = new ProviderId("of", "foo");
         TestProvider pFoo = new TestProvider(fooId);
         TestProviderService psFoo = registry.register(pFoo);
         assertEquals("incorrect provider count", 1, registry.getProviders().size());
         assertThat("provider not found", registry.getProviders().contains(fooId));
         assertEquals("incorrect provider", psFoo.provider(), pFoo);
 
-        ProviderId barId = new ProviderId("bar");
+        ProviderId barId = new ProviderId("of", "bar");
         TestProvider pBar = new TestProvider(barId);
         TestProviderService psBar = registry.register(pBar);
         assertEquals("incorrect provider count", 2, registry.getProviders().size());
@@ -52,7 +52,7 @@
     @Test(expected = IllegalStateException.class)
     public void duplicateRegistration() {
         TestProviderRegistry registry = new TestProviderRegistry();
-        TestProvider pFoo = new TestProvider(new ProviderId("foo"));
+        TestProvider pFoo = new TestProvider(new ProviderId("of", "foo"));
         registry.register(pFoo);
         registry.register(pFoo);
     }
@@ -60,13 +60,13 @@
     @Test
     public void voidUnregistration() {
         TestProviderRegistry registry = new TestProviderRegistry();
-        registry.unregister(new TestProvider(new ProviderId("foo")));
+        registry.unregister(new TestProvider(new ProviderId("of", "foo")));
     }
 
     @Test(expected = IllegalStateException.class)
     public void unregistration() {
         TestProviderRegistry registry = new TestProviderRegistry();
-        TestProvider pFoo = new TestProvider(new ProviderId("foo"));
+        TestProvider pFoo = new TestProvider(new ProviderId("of", "foo"));
         TestProviderService psFoo = registry.register(pFoo);
         registry.unregister(pFoo);
         psFoo.checkValidity();
diff --git a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderTest.java b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderTest.java
index 745aebc..c2e5cfc 100644
--- a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderTest.java
@@ -11,7 +11,7 @@
 
     @Test
     public void basics() {
-        ProviderId id = new ProviderId("foo.bar");
+        ProviderId id = new ProviderId("of", "foo.bar");
         TestProvider provider = new TestProvider(id);
         assertEquals("incorrect id", id, provider.id());
     }
diff --git a/core/api/src/test/java/org/onlab/onos/net/provider/ProviderIdTest.java b/core/api/src/test/java/org/onlab/onos/net/provider/ProviderIdTest.java
index 1c05507..1501eb9 100644
--- a/core/api/src/test/java/org/onlab/onos/net/provider/ProviderIdTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/provider/ProviderIdTest.java
@@ -11,8 +11,9 @@
     @Test
     public void basics() {
         new EqualsTester()
-                .addEqualityGroup(new ProviderId("foo"), new ProviderId("foo"))
-                .addEqualityGroup(new ProviderId("bar"))
+                .addEqualityGroup(new ProviderId("of", "foo"), new ProviderId("of", "foo"))
+                .addEqualityGroup(new ProviderId("snmp", "foo"), new ProviderId("snmp", "foo"))
+                .addEqualityGroup(new ProviderId("of", "bar"))
                 .testEquals();
     }