diff --git a/src/com/android/phone/vvm/omtp/SimChangeReceiver.java b/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
index 95fcb24..13e9c74 100644
--- a/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
+++ b/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
@@ -22,6 +22,7 @@
 import android.telephony.CarrierConfigManager;
 import android.telephony.SmsManager;
 import android.telephony.SubscriptionManager;
+import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.Log;
 
@@ -29,6 +30,8 @@
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.telephony.TelephonyIntents;
 import com.android.phone.vvm.omtp.sms.OmtpMessageSender;
+import com.android.phone.vvm.omtp.sms.OmtpStandardMessageSender;
+import com.android.phone.vvm.omtp.sms.OmtpCvvmMessageSender;
 import com.android.phone.vvm.omtp.sync.OmtpVvmSyncAccountManager;
 
 /**
@@ -41,6 +44,9 @@
  */
 public class SimChangeReceiver extends BroadcastReceiver {
     private final String TAG = "SimChangeReceiver";
+    // Whether CVVM is allowed, is currently false until settings to enable/disable vvm are added.
+    private boolean CVVM_ALLOWED = false;
+
     @Override
     public void onReceive(Context context, Intent intent) {
         final String action = intent.getAction();
@@ -86,7 +92,8 @@
         String vvmType = carrierConfig.getString(
                 CarrierConfigManager.STRING_VVM_TYPE, null);
 
-        if (!CarrierConfigManager.VVM_TYPE_OMTP.equals(vvmType)) {
+        if (!(TelephonyManager.VVM_TYPE_OMTP.equals(vvmType) ||
+                TelephonyManager.VVM_TYPE_CVVM.equals(vvmType))) {
             // This is not an OMTP visual voicemail compatible carrier.
             return;
         }
@@ -102,9 +109,27 @@
 
         Log.i(TAG, "Requesting VVM activation for subId: " + subId);
         SmsManager smsManager = SmsManager.getSmsManagerForSubscriptionId(subId);
-        OmtpMessageSender messageSender = new OmtpMessageSender(smsManager,
-                (short) applicationPort, destinationNumber, OmtpConstants.CLIENT_TYPE_GOOGLE_10,
-                OmtpConstants.PROTOCOL_VERSION1_1, null);
-        messageSender.requestVvmActivation(null);
+
+        OmtpMessageSender messageSender = null;
+        switch (vvmType) {
+            case TelephonyManager.VVM_TYPE_OMTP:
+                messageSender = new OmtpStandardMessageSender(smsManager, (short) applicationPort,
+                        destinationNumber, null, OmtpConstants.PROTOCOL_VERSION1_1, null);
+                break;
+            case TelephonyManager.VVM_TYPE_CVVM:
+                if (CVVM_ALLOWED) {
+                    messageSender = new OmtpCvvmMessageSender(smsManager, (short) applicationPort,
+                            destinationNumber);
+                }
+                break;
+            default:
+                Log.w(TAG, "Unexpected visual voicemail type: "+vvmType);
+        }
+
+        // It should be impossible for the messageSender to be null because the two types of vvm
+        // were checked earlier.
+        if (messageSender != null) {
+            messageSender.requestVvmActivation(null);
+        }
     }
-}
+}
\ No newline at end of file
diff --git a/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java b/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java
new file mode 100644
index 0000000..ef4e40b
--- /dev/null
+++ b/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015 Google Inc. All Rights Reserved.
+ *
+ * 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 com.android.phone.vvm.omtp.sms;
+
+import android.annotation.Nullable;
+import android.app.PendingIntent;
+import android.telephony.SmsManager;
+
+import com.android.phone.vvm.omtp.OmtpConstants;
+
+/**
+ * An implementation of the OmtpMessageSender for T-Mobile.
+ */
+public class OmtpCvvmMessageSender extends OmtpMessageSender {
+    public OmtpCvvmMessageSender(SmsManager smsManager, short applicationPort,
+            String destinationNumber) {
+        super(smsManager, applicationPort, destinationNumber);
+    }
+
+    @Override
+    public void requestVvmActivation(@Nullable PendingIntent sentIntent) {
+        sendCvvmMessage(OmtpConstants.ACTIVATE_REQUEST, sentIntent);
+    }
+
+    @Override
+    public void requestVvmDeactivation(@Nullable PendingIntent sentIntent) {
+        sendCvvmMessage(OmtpConstants.DEACTIVATE_REQUEST, sentIntent);
+    }
+
+    @Override
+    public void requestVvmStatus(@Nullable PendingIntent sentIntent) {
+        sendCvvmMessage(OmtpConstants.STATUS_REQUEST, sentIntent);
+    }
+
+    private void sendCvvmMessage(String request, PendingIntent sentIntent) {
+        StringBuilder sb = new StringBuilder().append(request);
+        sb.append(OmtpConstants.SMS_PREFIX_SEPARATOR);
+        appendField(sb, "dt", "6");
+        sendSms(sb.toString(), sentIntent);
+    }
+}
diff --git a/src/com/android/phone/vvm/omtp/sms/OmtpMessageSender.java b/src/com/android/phone/vvm/omtp/sms/OmtpMessageSender.java
index 0011ac3..9080292 100644
--- a/src/com/android/phone/vvm/omtp/sms/OmtpMessageSender.java
+++ b/src/com/android/phone/vvm/omtp/sms/OmtpMessageSender.java
@@ -18,7 +18,6 @@
 import android.annotation.Nullable;
 import android.app.PendingIntent;
 import android.telephony.SmsManager;
-import android.text.TextUtils;
 
 import com.android.phone.vvm.omtp.OmtpConstants;
 import com.android.services.telephony.Log;
@@ -34,103 +33,44 @@
  * <p>
  * Provides simple APIs to send different types of mobile originated OMTP SMS to the VVM server.
  */
-public class OmtpMessageSender {
-    private static final String TAG = "OmtpMessageSender";
-    private final SmsManager mSmsManager;
-    private final short mApplicationPort;
-    private final String mDestinationNumber;
-    private final String mClientType;
-    private final String mProtocolVersion;
-    private final String mClientPrefix;
+public abstract class OmtpMessageSender {
+    protected static final String TAG = "OmtpMessageSender";
+    protected short mApplicationPort;
+    protected String mDestinationNumber;
+    protected SmsManager mSmsManager;
 
-    /**
-     * Creates a new instance of OmtpMessageSenderImpl.
-     *
-     * @param smsManager SMS sending library. There is a different SmsManager for each SIM.
-     * @param applicationPort If set to a value > 0 then a binary sms is sent to this port number.
-     *            Otherwise, a standard text SMS is sent.
-     * @param destinationNumber Destination number to be used.
-     * @param clientType The "ct" field to be set in the MO message. This is the value used by the
-     *            VVM server to identify the client. Certain VVM servers require a specific agreed
-     *            value for this field.
-     * @param protocolVersion OMTP protocol version.
-     * @param clientPrefix The client prefix requested to be used by the server in its MT messages.
-     */
     public OmtpMessageSender(SmsManager smsManager, short applicationPort,
-            String destinationNumber, String clientType, String protocolVersion,
-            String clientPrefix) {
+            String destinationNumber) {
         mSmsManager = smsManager;
         mApplicationPort = applicationPort;
         mDestinationNumber = destinationNumber;
-        mClientType = clientType;
-        mProtocolVersion = protocolVersion;
-        mClientPrefix = clientPrefix;
     }
 
-
-    // Activate message:
-    // V1.1: Activate:pv=<value>;ct=<value>
-    // V1.2: Activate:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
-    // V1.3: Activate:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
     /**
      * Sends a request to the VVM server to activate VVM for the current subscriber.
      *
      * @param sentIntent If not NULL this PendingIntent is broadcast when the message is
      *            successfully sent, or failed.
      */
-    public void requestVvmActivation(@Nullable PendingIntent sentIntent) {
-        StringBuilder sb = new StringBuilder().append(OmtpConstants.ACTIVATE_REQUEST);
+    public void requestVvmActivation(@Nullable PendingIntent sentIntent) {}
 
-        appendProtocolVersionAndClientType(sb);
-        if (TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_2) ||
-                TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_3)) {
-            appendApplicationPort(sb);
-            appendClientPrefix(sb);
-        }
-
-        sendSms(sb.toString(), sentIntent);
-    }
-
-    // Deactivate message:
-    // V1.1: Deactivate:pv=<value>;ct=<string>
-    // V1.2: Deactivate:pv=<value>;ct=<string>
-    // V1.3: Deactivate:pv=<value>;ct=<string>
     /**
      * Sends a request to the VVM server to deactivate VVM for the current subscriber.
      *
      * @param sentIntent If not NULL this PendingIntent is broadcast when the message is
      *            successfully sent, or failed.
      */
-    public void requestVvmDeactivation(@Nullable PendingIntent sentIntent) {
-        StringBuilder sb = new StringBuilder().append(OmtpConstants.DEACTIVATE_REQUEST);
-        appendProtocolVersionAndClientType(sb);
+    public void requestVvmDeactivation(@Nullable PendingIntent sentIntent) {}
 
-        sendSms(sb.toString(), sentIntent);
-    }
-
-    // Status message:
-    // V1.1: STATUS
-    // V1.2: STATUS
-    // V1.3: STATUS:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
     /**
      * Send a request to the VVM server to get account status of the current subscriber.
      *
      * @param sentIntent If not NULL this PendingIntent is broadcast when the message is
      *            successfully sent, or failed.
      */
-    public void requestVvmStatus(@Nullable PendingIntent sentIntent) {
-        StringBuilder sb = new StringBuilder().append(OmtpConstants.STATUS_REQUEST);
+    public void requestVvmStatus(@Nullable PendingIntent sentIntent) {}
 
-        if (TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_3)) {
-            appendProtocolVersionAndClientType(sb);
-            appendApplicationPort(sb);
-            appendClientPrefix(sb);
-        }
-
-        sendSms(sb.toString(), sentIntent);
-    }
-
-    private void sendSms(String text, PendingIntent sentIntent) {
+    protected void sendSms(String text, PendingIntent sentIntent) {
         // If application port is set to 0 then send simple text message, else send data message.
         if (mApplicationPort == 0) {
             Log.v(TAG, String.format("Sending TEXT sms '%s' to %s", text, mDestinationNumber));
@@ -150,24 +90,7 @@
         }
     }
 
-    private void appendProtocolVersionAndClientType(StringBuilder sb) {
-        sb.append(OmtpConstants.SMS_PREFIX_SEPARATOR);
-        appendField(sb, OmtpConstants.PROTOCOL_VERSION, mProtocolVersion);
-        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
-        appendField(sb, OmtpConstants.CLIENT_TYPE, mClientType);
-    }
-
-    private void appendApplicationPort(StringBuilder sb) {
-        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
-        appendField(sb, OmtpConstants.APPLICATION_PORT, mApplicationPort);
-    }
-
-    private void appendClientPrefix(StringBuilder sb) {
-        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
-        sb.append(mClientPrefix);
-    }
-
-    private void appendField(StringBuilder sb, String field, Object value) {
+    protected void appendField(StringBuilder sb, String field, Object value) {
         sb.append(field).append(OmtpConstants.SMS_KEY_VALUE_SEPARATOR).append(value);
     }
 }
diff --git a/src/com/android/phone/vvm/omtp/sms/OmtpStandardMessageSender.java b/src/com/android/phone/vvm/omtp/sms/OmtpStandardMessageSender.java
new file mode 100644
index 0000000..05276e1
--- /dev/null
+++ b/src/com/android/phone/vvm/omtp/sms/OmtpStandardMessageSender.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2015 Google Inc. All Rights Reserved.
+ *
+ * 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 com.android.phone.vvm.omtp.sms;
+
+import android.annotation.Nullable;
+import android.app.PendingIntent;
+import android.telephony.SmsManager;
+import android.text.TextUtils;
+
+import com.android.phone.vvm.omtp.OmtpConstants;
+
+/**
+ * A implementation of the OmtpMessageSender using the standard OMTP sms protocol.
+ */
+public class OmtpStandardMessageSender extends OmtpMessageSender {
+    private final String mClientType;
+    private final String mProtocolVersion;
+    private final String mClientPrefix;
+
+    /**
+     * Creates a new instance of OmtpStandardMessageSender.
+     *
+     * @param smsManager SMS sending library. There is a different SmsManager for each SIM.
+     * @param applicationPort If set to a value > 0 then a binary sms is sent to this port number.
+     *            Otherwise, a standard text SMS is sent.
+     * @param destinationNumber Destination number to be used.
+     * @param clientType The "ct" field to be set in the MO message. This is the value used by the
+     *            VVM server to identify the client. Certain VVM servers require a specific agreed
+     *            value for this field.
+     * @param protocolVersion OMTP protocol version.
+     * @param clientPrefix The client prefix requested to be used by the server in its MT messages.
+     */
+    public OmtpStandardMessageSender(SmsManager smsManager, short applicationPort,
+            String destinationNumber, String clientType, String protocolVersion,
+            String clientPrefix) {
+        super(smsManager, applicationPort, destinationNumber);
+        mClientType = clientType;
+        mProtocolVersion = protocolVersion;
+        mClientPrefix = clientPrefix;
+    }
+
+    // Activate message:
+    // V1.1: Activate:pv=<value>;ct=<value>
+    // V1.2: Activate:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
+    // V1.3: Activate:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
+    @Override
+    public void requestVvmActivation(@Nullable PendingIntent sentIntent) {
+        StringBuilder sb = new StringBuilder().append(OmtpConstants.ACTIVATE_REQUEST);
+
+        appendProtocolVersionAndClientType(sb);
+        if (TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_2) ||
+                TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_3)) {
+            appendApplicationPort(sb);
+            appendClientPrefix(sb);
+        }
+
+        sendSms(sb.toString(), sentIntent);
+    }
+
+    // Deactivate message:
+    // V1.1: Deactivate:pv=<value>;ct=<string>
+    // V1.2: Deactivate:pv=<value>;ct=<string>
+    // V1.3: Deactivate:pv=<value>;ct=<string>
+    @Override
+    public void requestVvmDeactivation(@Nullable PendingIntent sentIntent) {
+        StringBuilder sb = new StringBuilder().append(OmtpConstants.DEACTIVATE_REQUEST);
+        appendProtocolVersionAndClientType(sb);
+
+        sendSms(sb.toString(), sentIntent);
+    }
+
+    // Status message:
+    // V1.1: STATUS
+    // V1.2: STATUS
+    // V1.3: STATUS:pv=<value>;ct=<value>;pt=<value>;<Clientprefix>
+    @Override
+    public void requestVvmStatus(@Nullable PendingIntent sentIntent) {
+        StringBuilder sb = new StringBuilder().append(OmtpConstants.STATUS_REQUEST);
+
+        if (TextUtils.equals(mProtocolVersion, OmtpConstants.PROTOCOL_VERSION1_3)) {
+            appendProtocolVersionAndClientType(sb);
+            appendApplicationPort(sb);
+            appendClientPrefix(sb);
+        }
+
+        sendSms(sb.toString(), sentIntent);
+    }
+
+    private void appendProtocolVersionAndClientType(StringBuilder sb) {
+        sb.append(OmtpConstants.SMS_PREFIX_SEPARATOR);
+        appendField(sb, OmtpConstants.PROTOCOL_VERSION, mProtocolVersion);
+        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
+        appendField(sb, OmtpConstants.CLIENT_TYPE, mClientType);
+    }
+
+    private void appendApplicationPort(StringBuilder sb) {
+        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
+        appendField(sb, OmtpConstants.APPLICATION_PORT, mApplicationPort);
+    }
+
+    private void appendClientPrefix(StringBuilder sb) {
+        sb.append(OmtpConstants.SMS_FIELD_SEPARATOR);
+        sb.append(mClientPrefix);
+    }
+}