diff --git a/services/tunnelbroker/src/libcpp/src/Database/DatabaseManager.cpp b/services/tunnelbroker/src/libcpp/src/Database/DatabaseManager.cpp
--- a/services/tunnelbroker/src/libcpp/src/Database/DatabaseManager.cpp
+++ b/services/tunnelbroker/src/libcpp/src/Database/DatabaseManager.cpp
@@ -40,7 +40,8 @@
       Aws::DynamoDB::Model::AttributeValue(item.getNotifyToken()));
   request.AddItem(
       DeviceSessionItem::FIELD_DEVICE_TYPE,
-      Aws::DynamoDB::Model::AttributeValue(item.getDeviceType()));
+      Aws::DynamoDB::Model::AttributeValue(
+          std::to_string(item.getDeviceType())));
   request.AddItem(
       DeviceSessionItem::FIELD_APP_VERSION,
       Aws::DynamoDB::Model::AttributeValue(item.getAppVersion()));
diff --git a/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.h b/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.h
--- a/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.h
+++ b/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.h
@@ -13,7 +13,7 @@
   std::string deviceID;
   std::string pubKey;
   std::string notifyToken;
-  std::string deviceType;
+  size_t deviceType;
   std::string appVersion;
   std::string deviceOs;
   int64_t checkpointTime = 0;
@@ -33,6 +33,8 @@
   static const std::string FIELD_EXPIRE;
   static const std::string FIELD_IS_ONLINE;
 
+  enum DeviceTypes { MOBILE = 0, WEB = 1, KEYSERVER = 2 };
+
   PrimaryKeyDescriptor getPrimaryKeyDescriptor() const override;
   PrimaryKeyValue getPrimaryKeyValue() const override;
   std::string getTableName() const override;
@@ -40,7 +42,7 @@
   std::string getDeviceID() const;
   std::string getPubKey() const;
   std::string getNotifyToken() const;
-  std::string getDeviceType() const;
+  size_t getDeviceType() const;
   std::string getAppVersion() const;
   std::string getDeviceOs() const;
   int64_t getCheckpointTime() const;
@@ -53,7 +55,7 @@
       const std::string deviceID,
       const std::string pubKey,
       const std::string notifyToken,
-      const std::string deviceType,
+      size_t deviceType,
       const std::string appVersion,
       const std::string deviceOs);
   DeviceSessionItem(const AttributeValues &itemFromDB);
diff --git a/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.cpp b/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.cpp
--- a/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.cpp
+++ b/services/tunnelbroker/src/libcpp/src/Database/DeviceSessionItem.cpp
@@ -24,7 +24,7 @@
     const std::string deviceID,
     const std::string pubKey,
     const std::string notifyToken,
-    const std::string deviceType,
+    const size_t deviceType,
     const std::string appVersion,
     const std::string deviceOs)
     : sessionID(sessionID),
@@ -49,7 +49,6 @@
     throw std::runtime_error("Error: DeviceID format is wrong.");
   }
   tools::checkIfNotEmpty("pubKey", this->pubKey);
-  tools::checkIfNotEmpty("deviceType", this->deviceType);
   tools::checkIfNotEmpty("appVersion", this->appVersion);
   tools::checkIfNotEmpty("deviceOs", this->deviceOs);
 }
@@ -63,7 +62,7 @@
     this->notifyToken =
         itemFromDB.at(DeviceSessionItem::FIELD_NOTIFY_TOKEN).GetS();
     this->deviceType =
-        itemFromDB.at(DeviceSessionItem::FIELD_DEVICE_TYPE).GetS();
+        std::stoul(itemFromDB.at(DeviceSessionItem::FIELD_DEVICE_TYPE).GetS());
     this->appVersion =
         itemFromDB.at(DeviceSessionItem::FIELD_APP_VERSION).GetS();
     this->deviceOs = itemFromDB.at(DeviceSessionItem::FIELD_DEVICE_OS).GetS();
@@ -109,7 +108,7 @@
   return this->notifyToken;
 }
 
-std::string DeviceSessionItem::getDeviceType() const {
+size_t DeviceSessionItem::getDeviceType() const {
   return this->deviceType;
 }
 
diff --git a/services/tunnelbroker/src/libcpp/test/DatabaseManagerTest.cpp b/services/tunnelbroker/src/libcpp/test/DatabaseManagerTest.cpp
--- a/services/tunnelbroker/src/libcpp/test/DatabaseManagerTest.cpp
+++ b/services/tunnelbroker/src/libcpp/test/DatabaseManagerTest.cpp
@@ -141,7 +141,7 @@
       "ECqgx4zqajPTzVt7EAOGaIh/dPyQ6x2Ul1GlkkSYXUhhixEzExGp9g84eCyVkbCB"
       "U3SK6SNKyR7anAXDVQIDAQAB",
       "hbI93aGAwPF9au0eYsawRz0jtYi4lSFXC9KleyQDg+6J+UW1kiWvE3",
-      "phone",
+      database::DeviceSessionItem::DeviceTypes::MOBILE,
       "ios:1.1.1",
       "iOS 99.99.99");
   EXPECT_EQ(
@@ -169,7 +169,7 @@
       "mobile:" + tools::generateRandomString(DEVICEID_CHAR_LENGTH),
       tools::generateRandomString(451),
       tools::generateRandomString(64),
-      tools::generateRandomString(12),
+      database::DeviceSessionItem::DeviceTypes::MOBILE,
       tools::generateRandomString(12),
       tools::generateRandomString(12));
   EXPECT_EQ(
@@ -219,7 +219,7 @@
       "ECqgx4zqajPTzVt7EAOGaIh/dPyQ6x2Ul1GlkkSYXUhhixEzExGp9g84eCyVkbCB"
       "U3SK6SNKyR7anAXDVQIDAQAB",
       "hbI93aGAwPF9au0eYsawRz0jtYi4lSFXC9KleyQDg+6J+UW1kiWvE3",
-      "phone",
+      database::DeviceSessionItem::DeviceTypes::MOBILE,
       "ios:1.1.1",
       "iOS 99.99.99");
   EXPECT_EQ(
@@ -254,7 +254,7 @@
       "ECqgx4zqajPTzVt7EAOGaIh/dPyQ6x2Ul1GlkkSYXUhhixEzExGp9g84eCyVkbCB"
       "U3SK6SNKyR7anAXDVQIDAQAB",
       "hbI93aGAwPF9au0eYsawRz0jtYi4lSFXC9KleyQDg+6J+UW1kiWvE3",
-      "phone",
+      database::DeviceSessionItem::DeviceTypes::MOBILE,
       "ios:1.1.1",
       "iOS 99.99.99");
   EXPECT_EQ(