diff --git a/.gitignore b/.gitignore
index 674fc49..aeed094 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,5 @@ erl_crash.dump
 
 # Examples
 */polaris/*
+
+/bin/enum_gen
diff --git a/bin/enum_gen b/bin/enum_gen
deleted file mode 100755
index d527668..0000000
Binary files a/bin/enum_gen and /dev/null differ
diff --git a/config/config.exs b/config/config.exs
index 40896b3..c04ed23 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -11,7 +11,7 @@ config :tres,
   callback_args: []
 
 config :logger,
-  level: :info,
-  format: "$date $time [$level] $metadata$message\n",
-  metadata: [:application],
+  level: :debug,
+  format: "$date $time [$level] $message\n",
+  metadata: [],
   handle_otp_reports: true
diff --git a/examples/leader_example/lib/leader_example/leader.ex b/examples/leader_example/lib/leader_example/leader.ex
index 44fad09..f895dc1 100644
--- a/examples/leader_example/lib/leader_example/leader.ex
+++ b/examples/leader_example/lib/leader_example/leader.ex
@@ -5,7 +5,7 @@ defmodule LeaderExample.Leader do
 
   require Logger
 
-  def start_link([datapath_id, args]) do
+  def start_link(datapath_id, args) do
     :locks_leader.start_link(__MODULE__, [datapath_id, args], [])
   end
 
diff --git a/examples/learning_switch/lib/learning_switch/ofctl.ex b/examples/learning_switch/lib/learning_switch/ofctl.ex
index c060fec..0abaef1 100644
--- a/examples/learning_switch/lib/learning_switch/ofctl.ex
+++ b/examples/learning_switch/lib/learning_switch/ofctl.ex
@@ -22,7 +22,7 @@ defmodule LearningSwitch.Ofctl do
     ]
   end
 
-  def start_link([datapath_id, args]) do
+  def start_link(datapath_id, args) do
     GenServer.start_link(__MODULE__, [datapath_id, args])
   end
 
diff --git a/examples/patch_panel/lib/patch_panel/openflow/controller.ex b/examples/patch_panel/lib/patch_panel/openflow/controller.ex
index ac12470..bbecf04 100644
--- a/examples/patch_panel/lib/patch_panel/openflow/controller.ex
+++ b/examples/patch_panel/lib/patch_panel/openflow/controller.ex
@@ -26,7 +26,7 @@ defmodule PatchPanel.Openflow.Controller do
     end
   end
 
-  def start_link([{datapath_id, _aux_id}, _start_args]) do
+  def start_link({datapath_id, _aux_id}, _start_args) do
     GenServer.start_link(__MODULE__, [datapath_id])
   end
 
diff --git a/examples/simple_router/lib/simple_router/openflow/controller.ex b/examples/simple_router/lib/simple_router/openflow/controller.ex
index 95b2146..16dfa80 100644
--- a/examples/simple_router/lib/simple_router/openflow/controller.ex
+++ b/examples/simple_router/lib/simple_router/openflow/controller.ex
@@ -21,7 +21,7 @@ defmodule SimpleRouter.Openflow.Controller do
     ]
   end
 
-  def start_link([{datapath_id, _aux_id}, _start_args]) do
+  def start_link({datapath_id, _aux_id}, _start_args) do
     GenServer.start_link(__MODULE__, [datapath_id])
   end
 
diff --git a/lib/tres/example_handler.ex b/lib/tres/example_handler.ex
index 6a392bc..88436ca 100644
--- a/lib/tres/example_handler.ex
+++ b/lib/tres/example_handler.ex
@@ -10,13 +10,13 @@ defmodule Tres.ExampleHandler do
               conn_ref: nil
   end
 
-  def start_link([datapath, args]) do
+  def start_link(datapath, args) do
     GenServer.start_link(__MODULE__, [datapath, args])
   end
 
   def init([{datapath_id, aux_id}, _args]) do
     info(
-      "[#{__MODULE__}] Switch Ready: " <>
+      "Switch Ready: " <>
         "datapath_id: #{datapath_id} " <> "aux_id: #{aux_id} " <> "on #{inspect(self())}"
     )
 
@@ -36,14 +36,19 @@ defmodule Tres.ExampleHandler do
     {:noreply, state}
   end
 
+  def handle_info({:switch_disconnected, _reason}, state) do
+    :ok = warn("Switch disconnected")
+    {:stop, :normal, state}
+  end
+
   def handle_info({:switch_hang, _datapath_id}, state) do
-    :ok = warn("[#{__MODULE__}] Switch possible hang: datapath_id: #{state.datapath_id}")
+    :ok = warn("Switch possible hang: datapath_id: #{state.datapath_id}")
     {:noreply, state}
   end
 
   # `Catch all` function is required.
   def handle_info(info, state) do
-    :ok = warn("[#{__MODULE__}] unhandled message #{inspect(info)}: #{state.datapath_id}")
+    :ok = warn("unhandled message #{inspect(info)}: #{state.datapath_id}")
     {:noreply, state}
   end
 
@@ -61,7 +66,7 @@ defmodule Tres.ExampleHandler do
 
   defp handle_desc_stats_reply(desc, datapath_id) do
     info(
-      "[#{__MODULE__}] Switch Desc: " <>
+      "Switch Desc: " <>
         "mfr = #{desc.mfr_desc} " <>
         "hw = #{desc.hw_desc} " <> "sw = #{desc.sw_desc} " <> "for #{datapath_id}"
     )
@@ -70,7 +75,7 @@ defmodule Tres.ExampleHandler do
   defp handle_port_desc_stats_reply(port_desc, datapath_id) do
     for port <- port_desc.ports do
       info(
-        "[#{__MODULE__}] Switch has port: " <>
+        "Switch has port: " <>
           "number = #{port.number} " <>
           "hw_addr = #{port.hw_addr} " <>
           "name = #{port.name} " <>
diff --git a/lib/tres/message_handler_sup.ex b/lib/tres/message_handler_sup.ex
index 6797ffb..81a277f 100644
--- a/lib/tres/message_handler_sup.ex
+++ b/lib/tres/message_handler_sup.ex
@@ -1,34 +1,19 @@
 defmodule Tres.MessageHandlerSup do
   use Supervisor
 
-  def start_link() do
-    Supervisor.start_link(__MODULE__, [], name: __MODULE__)
-  end
-
-  def init(_init_args) do
-    children = []
-
-    Supervisor.init(
-      children,
-      strategy: :one_for_one,
-      max_restarts: 5,
-      max_seconds: 10
-    )
-  end
+  # API functions
 
   def start_child(dpid) do
-    {cb_mod, _cb_args} = Tres.Utils.get_callback_module()
-    child_spec = cb_mod.handler_spec(dpid)
-    {:ok, pid} = Supervisor.start_child(__MODULE__, child_spec)
+    {_cb_mod, cb_args} = Tres.Utils.get_callback_module()
+    {:ok, pid} = Supervisor.start_child(__MODULE__, [dpid, cb_args])
     :ok = Tres.SwitchRegistry.register_handler_pid(dpid, pid)
     {:ok, pid}
   end
 
   def terminate_child(dpid) do
     {cb_mod, _cb_args} = Tres.Utils.get_callback_module()
-    child_spec = cb_mod.handler_spec(dpid)
-    _ = Supervisor.terminate_child(__MODULE__, child_spec[:id])
-    _ = Supervisor.delete_child(__MODULE__, child_spec[:id])
+    _ = Supervisor.terminate_child(__MODULE__, {cb_mod, dpid})
+    _ = Supervisor.delete_child(__MODULE__, {cb_mod, dpid})
   end
 
   @spec count_handlers() :: non_neg_integer()
@@ -36,4 +21,37 @@ defmodule Tres.MessageHandlerSup do
     count_value = Supervisor.count_children(__MODULE__)
     count_value[:active]
   end
+
+  def start_link do
+    Supervisor.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  # supervisor callback functions
+
+  @impl Supervisor
+  def init(_init_args) do
+    children = [handler_spec()]
+
+    Supervisor.init(
+      children,
+      strategy: :simple_one_for_one,
+      max_restarts: 10,
+      max_seconds: 10
+    )
+  end
+
+  # private functions
+
+  defp handler_spec do
+    {cb_mod, _cb_args} = Tres.Utils.get_callback_module()
+
+    %{
+      id: :undefined,
+      start: {cb_mod, :start_link, []},
+      restart: :temporary,
+      shutdown: 5000,
+      type: :worker,
+      modules: [cb_mod]
+    }
+  end
 end
diff --git a/lib/tres/secure_channel.ex b/lib/tres/secure_channel.ex
index f8520e3..c89aaff 100644
--- a/lib/tres/secure_channel.ex
+++ b/lib/tres/secure_channel.ex
@@ -56,6 +56,7 @@ defmodule Tres.SecureChannel do
   end
 
   def handle_event(:info, {:tcp_closed, socket}, _state, %State{socket: socket} = state_data) do
+    :ok = debug("TCP disconnected with #{state_data.ip_addr}:#{state_data.port}")
     close_connection(:tcp_closed, state_data)
   end
 
@@ -609,7 +610,6 @@ defmodule Tres.SecureChannel do
 
   defp close_connection(:handler_error, state_data) do
     debug("connection terminated: Got handler error")
-    _ = send(state_data.handler_pid, {:switch_disconnected, :handler_error})
     {:stop, :normal, %{state_data | socket: nil}}
   end
 
@@ -627,6 +627,7 @@ defmodule Tres.SecureChannel do
 
   defp close_connection({:handler_down, reason}, state_data) do
     debug("connection terminated: Handler process down by #{inspect(reason)}")
+    _ = send(state_data.handler_pid, {:switch_disconnected, :handler_error})
     {:stop, :normal, %{state_data | socket: nil}}
   end
 
diff --git a/lib/tres/secure_channel_state.ex b/lib/tres/secure_channel_state.ex
index 6ab8283..e5312c0 100644
--- a/lib/tres/secure_channel_state.ex
+++ b/lib/tres/secure_channel_state.ex
@@ -1,4 +1,6 @@
 defmodule Tres.SecureChannelState do
+  use Bitwise
+
   defstruct(
     handler_pid: nil,
     handler_ref: nil,
@@ -43,26 +45,27 @@ defmodule Tres.SecureChannelState do
     }
   end
 
-  def increment_transaction_id(table_ref) do
-    :ets.update_counter(table_ref, :datapath_xid, {2, 1, 0xFFFFFFFF, 0})
+  @spec increment_transaction_id(:counters.counters_ref()) :: integer()
+  def increment_transaction_id(counter_ref) do
+    :ok = :counters.add(counter_ref, 1, 1)
+    get_transaction_id(counter_ref)
   end
 
-  def set_transaction_id(table_ref, xid) do
-    :ets.insert(table_ref, {:datapath_xid, xid})
+  @spec set_transaction_id(:counters.counters_ref(), integer()) :: integer()
+  def set_transaction_id(counter_ref, xid) do
+    :ok = :counters.put(counter_ref, 1, xid)
+    get_transaction_id(counter_ref)
   end
 
-  def get_transaction_id(table_ref) do
-    case :ets.lookup(table_ref, :datapath_xid) do
-      [{_, xid} | _] -> xid
-    end
+  @spec get_transaction_id(:counters.counters_ref()) :: integer()
+  def get_transaction_id(counter_ref) do
+    :counters.get(counter_ref, 1) &&& 0xffffffff
   end
 
   # private functions
 
   @spec create_counter() :: reference()
   defp create_counter do
-    table_ref = :ets.new(:xid_counter, [:set, :private])
-    _ = :ets.insert(table_ref, {:datapath_xid, 0})
-    {:ok, table_ref}
+    {:ok, :counters.new(1, [])}
   end
 end