diff --git a/.travis.yml b/.travis.yml
index d458396..097035a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,7 +21,9 @@ before_install:
   - sudo ovs-vsctl add-br br0
   - sudo ovs-vsctl set bridge br0 datapath_type=netdev
   - sudo ovs-vsctl set bridge br0 protocols=OpenFlow13
+  - sudo ovs-vsctl set bridge br0 other-config:datapath-id=0000000000000001
   - sudo ovs-vsctl set-controller br0 tcp:127.0.0.1:6653
+  - sudo ovs-vsctl set-manager ptcp:6640
   - sudo ovs-vsctl show
   - cd -
   
diff --git a/lib/openflow/packet_in.ex b/lib/openflow/packet_in.ex
index c73b2c3..ea4a738 100644
--- a/lib/openflow/packet_in.ex
+++ b/lib/openflow/packet_in.ex
@@ -43,29 +43,4 @@ defmodule Openflow.PacketIn do
       data: data
     }
   end
-
-  def to_binary(%PacketIn{} = packet_in) do
-    %PacketIn{
-      buffer_id: buffer_id,
-      total_len: total_len,
-      reason: reason,
-      table_id: table_id,
-      cookie: cookie,
-      in_port: in_port,
-      match: match_fields,
-      data: data
-    } = packet_in
-
-    buffer_id_int = Openflow.Utils.get_enum(buffer_id, :buffer_id)
-    reason_int = Openflow.Utils.get_enum(reason, :packet_in_reason)
-    table_id_int = Openflow.Utils.get_enum(table_id, :table_id)
-
-    match_fields_bin =
-      [{:in_port, in_port} | match_fields]
-      |> Openflow.Match.new()
-      |> Openflow.Match.to_binary()
-
-    <<buffer_id_int::32, total_len::16, reason_int::8, table_id_int::8, cookie::64,
-      match_fields_bin::bytes, 0::size(2)-unit(8), data::bytes>>
-  end
 end
diff --git a/lib/openflow/role/reply.ex b/lib/openflow/role/reply.ex
index 0480a0f..24e6f73 100644
--- a/lib/openflow/role/reply.ex
+++ b/lib/openflow/role/reply.ex
@@ -14,19 +14,8 @@ defmodule Openflow.Role.Reply do
 
   def ofp_type, do: 25
 
-  def new(options \\ []) do
-    role = Keyword.get(options, :role, :nochange)
-    generation_id = Keyword.get(options, :generation_id, 0)
-    %Reply{role: role, generation_id: generation_id}
-  end
-
   def read(<<role_int::32, 0::size(4)-unit(8), generation_id::64>>) do
     role = Openflow.Enums.to_atom(role_int, :controller_role)
     %Reply{role: role, generation_id: generation_id}
   end
-
-  def to_binary(%Reply{role: role, generation_id: generation_id}) do
-    role_int = Openflow.Enums.to_int(role, :controller_role)
-    <<role_int::32, 0::size(4)-unit(8), generation_id::64>>
-  end
 end
diff --git a/lib/openflow/role/request.ex b/lib/openflow/role/request.ex
index 3bacde8..ee96941 100644
--- a/lib/openflow/role/request.ex
+++ b/lib/openflow/role/request.ex
@@ -21,11 +21,6 @@ defmodule Openflow.Role.Request do
     %Request{xid: xid, role: role, generation_id: generation_id}
   end
 
-  def read(<<role_int::32, 0::size(4)-unit(8), generation_id::64>>) do
-    role = Openflow.Enums.to_atom(role_int, :controller_role)
-    %Request{role: role, generation_id: generation_id}
-  end
-
   def to_binary(%Request{role: role, generation_id: generation_id}) do
     role_int = Openflow.Enums.to_int(role, :controller_role)
     <<role_int::32, 0::size(4)-unit(8), generation_id::64>>
diff --git a/lib/tres/example_handler.ex b/lib/tres/example_handler.ex
index 88436ca..ae96954 100644
--- a/lib/tres/example_handler.ex
+++ b/lib/tres/example_handler.ex
@@ -7,33 +7,50 @@ defmodule Tres.ExampleHandler do
   defmodule State do
     defstruct datapath_id: nil,
               aux_id: nil,
-              conn_ref: nil
+              queue: :queue.new(),
+              client: nil
+  end
+
+  # API functions
+
+  @spec send(String.t(), map()) :: :ok
+  def send(datapath_id, msg), do: send_message(msg, datapath_id)
+
+  @spec get(datapath_id :: String.t()) :: map() | nil
+  def get(datapath_id) do
+    datapath_id
+    |> lookup_handler_pid()
+    |> GenServer.call(:get)
   end
 
   def start_link(datapath, args) do
     GenServer.start_link(__MODULE__, [datapath, args])
   end
 
+  # GenServer callbacks
+
   def init([{datapath_id, aux_id}, _args]) do
-    info(
-      "Switch Ready: " <>
-        "datapath_id: #{datapath_id} " <> "aux_id: #{aux_id} " <> "on #{inspect(self())}"
-    )
-
-    _ = send_desc_stats_request(datapath_id)
-    _ = send_port_desc_stats_request(datapath_id)
-    state = %State{datapath_id: datapath_id, aux_id: aux_id}
-    {:ok, state}
+    :ok = info("datapath connected: #{datapath_id}")
+    :ok = send_flow_mod_add(datapath_id, priority: 0)
+    {:ok, %State{datapath_id: datapath_id, aux_id: aux_id}}
   end
 
-  def handle_info(%PortDesc.Reply{datapath_id: datapath_id} = desc, state) do
-    handle_port_desc_stats_reply(desc, datapath_id)
-    {:noreply, state}
+  def handle_call(:get, from, %State{queue: {[], []}} = state) do
+    {:noreply, %{state | client: from}}
   end
 
-  def handle_info(%Desc.Reply{datapath_id: datapath_id} = desc, state) do
-    handle_desc_stats_reply(desc, datapath_id)
-    {:noreply, state}
+  def handle_call(:get, _from, %State{} = state) do
+    {{:value, msg}, new_queue} = :queue.out(state.queue)
+    {:reply, msg, %{state | queue: new_queue}}
+  end
+
+  def handle_info(%{datapath_id: _datapath_id} = msg, %State{client: nil} = state) do
+    {:noreply, %{state | queue: :queue.in(msg, state.queue)}}
+  end
+
+  def handle_info(%{datapath_id: _datapath_id} = msg, state) do
+    GenServer.reply(state.client, msg)
+    {:noreply, %{state | client: nil}}
   end
 
   def handle_info({:switch_disconnected, _reason}, state) do
@@ -41,47 +58,10 @@ defmodule Tres.ExampleHandler do
     {:stop, :normal, state}
   end
 
-  def handle_info({:switch_hang, _datapath_id}, state) do
-    :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("unhandled message #{inspect(info)}: #{state.datapath_id}")
     {:noreply, state}
   end
 
   # private functions
-
-  defp send_desc_stats_request(datapath_id) do
-    Desc.Request.new()
-    |> send_message(datapath_id)
-  end
-
-  defp send_port_desc_stats_request(datapath_id) do
-    PortDesc.Request.new()
-    |> send_message(datapath_id)
-  end
-
-  defp handle_desc_stats_reply(desc, datapath_id) do
-    info(
-      "Switch Desc: " <>
-        "mfr = #{desc.mfr_desc} " <>
-        "hw = #{desc.hw_desc} " <> "sw = #{desc.sw_desc} " <> "for #{datapath_id}"
-    )
-  end
-
-  defp handle_port_desc_stats_reply(port_desc, datapath_id) do
-    for port <- port_desc.ports do
-      info(
-        "Switch has port: " <>
-          "number = #{port.number} " <>
-          "hw_addr = #{port.hw_addr} " <>
-          "name = #{port.name} " <>
-          "config = #{inspect(port.config)} " <>
-          "current_speed = #{port.current_speed} " <> "on #{datapath_id}"
-      )
-    end
-  end
 end
diff --git a/test/lib/openflow/ofp_packet_in2_test.exs b/test/lib/openflow/ofp_packet_in2_test.exs
index 32d6e49..addb797 100644
--- a/test/lib/openflow/ofp_packet_in2_test.exs
+++ b/test/lib/openflow/ofp_packet_in2_test.exs
@@ -28,8 +28,14 @@ defmodule OfpPacketIn2Test do
         |> Kernel.elem(1)
 
       assert pktin.continuation_action_set == nil
-      assert pktin.continuation_actions == [%Openflow.Action.NxResubmitTable{in_port: :in_port, table_id: 5}]
-      assert pktin.continuation_bridge == <<8, 137, 105, 58, 5, 77, 183, 237, 163, 58, 25, 166, 212, 167, 209, 11>>
+
+      assert pktin.continuation_actions == [
+               %Openflow.Action.NxResubmitTable{in_port: :in_port, table_id: 5}
+             ]
+
+      assert pktin.continuation_bridge ==
+               <<8, 137, 105, 58, 5, 77, 183, 237, 163, 58, 25, 166, 212, 167, 209, 11>>
+
       assert pktin.continuation_conntracked == nil
       assert pktin.continuation_cookie == nil
       assert pktin.continuation_mirrors == nil
diff --git a/test/lib/openflow/ofp_resume_test.exs b/test/lib/openflow/ofp_resume_test.exs
index 3fdbe03..494d30e 100644
--- a/test/lib/openflow/ofp_resume_test.exs
+++ b/test/lib/openflow/ofp_resume_test.exs
@@ -11,8 +11,14 @@ defmodule OfpResumeTest do
         |> Kernel.elem(1)
 
       assert pktin.continuation_action_set == nil
-      assert pktin.continuation_actions == [%Openflow.Action.NxResubmitTable{in_port: :in_port, table_id: 5}]
-      assert pktin.continuation_bridge == <<8, 137, 105, 58, 5, 77, 183, 237, 163, 58, 25, 166, 212, 167, 209, 11>>
+
+      assert pktin.continuation_actions == [
+               %Openflow.Action.NxResubmitTable{in_port: :in_port, table_id: 5}
+             ]
+
+      assert pktin.continuation_bridge ==
+               <<8, 137, 105, 58, 5, 77, 183, 237, 163, 58, 25, 166, 212, 167, 209, 11>>
+
       assert pktin.continuation_conntracked == nil
       assert pktin.continuation_cookie == nil
       assert pktin.continuation_mirrors == nil
diff --git a/test/lib/ovsdb/openvswitch_test.exs b/test/lib/ovsdb/openvswitch_test.exs
new file mode 100644
index 0000000..d28f0ba
--- /dev/null
+++ b/test/lib/ovsdb/openvswitch_test.exs
@@ -0,0 +1,44 @@
+defmodule OVSDB.OpenvSwitchTest do
+  use ExUnit.Case, async: false
+
+  setup_all do
+    {:ok, pid} = OVSDB.start_child("127.0.0.1:6640")
+    {:ok, pid: pid}
+  end
+
+  describe "OVSDB.OpenvSwitch.find_by_name/3" do
+    test "with pid, table and name", context do
+      %{"datapath_id" => "0000000000000001"} = OVSDB.OpenvSwitch.find_by_name(context.pid, "Bridge", "br0")
+    end
+  end
+
+  describe "OVSDB.OpenvSwitch.add_br/2" do
+    test "with options", context do
+      OVSDB.OpenvSwitch.add_br(
+        context.pid,
+        name: "brx",
+        datapath_id: "0000000000000003"
+      )
+    end
+  end
+
+  describe "OVSDB.OpenvSwitch.set_controller/2" do
+    test "with options", context do
+      OVSDB.OpenvSwitch.add_br(
+        context.pid,
+        name: "brx",
+        target: "tcp:127.0.0.1:6653",
+        connection_mode: "out-of-band",
+        controller_rate_limit: 100,
+        controller_burst_limit: 25,
+        protocol: "OpenFlow13"
+      )
+    end
+  end
+
+  describe "OVSDB.OpenvSwitch.del_br/2" do
+    test "with pid and name", context do
+      OVSDB.OpenvSwitch.del_br(context.pid, "brx")
+    end
+  end
+end
diff --git a/test/lib/tres/handler_test.exs b/test/lib/tres/handler_test.exs
new file mode 100644
index 0000000..b811c74
--- /dev/null
+++ b/test/lib/tres/handler_test.exs
@@ -0,0 +1,178 @@
+defmodule Tres.HanderTest do
+  use ExUnit.Case
+
+  @datapath_id "0000000000000001"
+
+  setup_all do
+    :ok = wait_datapath_is_connected()
+    :ok = send_message(Openflow.FlowMod.new(command: :delete, table_id: :all))
+    :ok = send_message(Openflow.GroupMod.new(command: :delete, group_id: :all))
+    :ok = send_message(Openflow.MeterMod.new(command: :delete, meter_id: :all))
+  end
+
+  describe "Openflow RoleRequest message" do
+    test "with role and generation_id" do
+      send_message(Openflow.Role.Request.new(role: :nochange, generation_id: 1))
+      %Openflow.Role.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow standard PacketIn message" do
+    test "with arp_packet" do
+      send_message(
+        Openflow.PacketOut.new(
+          buffer_id: :no_buffer,
+          in_port: :controller,
+          actions: [Openflow.Action.Output.new(:controller)],
+          data: File.read!("test/packet_data/arp_packet.raw")
+        )
+      )
+
+      %Openflow.PacketIn{} = get_message()
+    end
+  end
+
+  describe "Openflow Nicira PacketIn2 message" do
+    test "with arp_packet" do
+      send_message(Openflow.NxSetPacketInFormat.new(:nxt_packet_in2))
+
+      send_message(
+        Openflow.FlowMod.new(
+          instructions: Openflow.Instruction.ApplyActions.new(Openflow.Action.NxController2.new())
+        )
+      )
+
+      send_message(
+        Openflow.PacketOut.new(
+          buffer_id: :no_buffer,
+          in_port: :controller,
+          actions: [Openflow.Action.Output.new(:controller)],
+          data: File.read!("test/packet_data/arp_packet.raw")
+        )
+      )
+
+      %Openflow.NxPacketIn2{} = get_message()
+    end
+  end
+
+  describe "Openflow FlowRemoved message" do
+    test "with a flow" do
+      send_message(
+        Openflow.FlowMod.new(flags: [:send_flow_rem], match: Openflow.Match.new(reg0: 99))
+      )
+
+      send_message(Openflow.FlowMod.new(command: :delete, match: Openflow.Match.new(reg0: 99)))
+      %Openflow.FlowRemoved{} = get_message()
+    end
+  end
+
+  describe "Openflow AggregateStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Aggregate.Request.new())
+      %Openflow.Multipart.Aggregate.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow DescStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Desc.Request.new())
+      %Openflow.Multipart.Desc.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow FlowStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Flow.Request.new())
+      %Openflow.Multipart.Flow.Reply{} = get_message()
+    end
+
+    test "with 3000 flows" do
+      Enum.each(1..3000, fn n ->
+        send_message(Openflow.FlowMod.new(match: Openflow.Match.new(reg0: n)))
+      end)
+
+      send_message(Openflow.Multipart.Flow.Request.new())
+      %Openflow.Multipart.Flow.Reply{flags: [:more]} = get_message()
+    end
+  end
+
+  describe "Openflow GroupStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Group.Request.new())
+      %Openflow.Multipart.Group.Reply{} = get_message()
+    end
+
+    test "with 3000 groups" do
+      Enum.each(1..3000, fn n -> send_message(Openflow.GroupMod.new(group_id: n)) end)
+      send_message(Openflow.Multipart.Group.Request.new())
+      %Openflow.Multipart.Group.Reply{flags: [:more]} = get_message()
+    end
+  end
+
+  describe "Openflow GroupDesc Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.GroupDesc.Request.new())
+      %Openflow.Multipart.GroupDesc.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow GroupFeatures Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.GroupFeatures.Request.new())
+      %Openflow.Multipart.GroupFeatures.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow MeterStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Meter.Request.new())
+      %Openflow.Multipart.Meter.Reply{} = get_message()
+    end
+
+    test "with 3000 meters" do
+      Enum.each(1..3000, fn n ->
+        send_message(
+          Openflow.MeterMod.new(
+            meter_id: n,
+            flags: [:pktps, :burst, :stats],
+            bands: [Openflow.MeterBand.Drop.new(rate: 1000, burst_size: 10)]
+          )
+        )
+      end)
+
+      send_message(Openflow.Multipart.Meter.Request.new())
+      %Openflow.Multipart.Meter.Reply{flags: [:more]} = get_message()
+    end
+  end
+
+  describe "Openflow PortDescStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.PortDesc.Request.new())
+      %Openflow.Multipart.PortDesc.Reply{} = get_message()
+    end
+  end
+
+  describe "Openflow PortStats Reply message" do
+    test "with no option" do
+      send_message(Openflow.Multipart.Port.Request.new())
+      %Openflow.Multipart.Port.Reply{} = get_message()
+    end
+  end
+
+  # helper
+
+  def wait_datapath_is_connected do
+    case Tres.SwitchRegistry.lookup_handler_pid(@datapath_id) do
+      nil -> wait_datapath_is_connected()
+      pid when is_pid(pid) -> :ok
+    end
+  end
+
+  def send_message(msg) do
+    :ok = Tres.ExampleHandler.send(@datapath_id, msg)
+  end
+
+  def get_message do
+    Tres.ExampleHandler.get(@datapath_id)
+  end
+end