diff --git a/docs/api/examples/post_vpcsvpcsidportsportidnio.txt b/docs/api/examples/post_vpcsvpcsidportsportidnio.txt
index cdcb7a4e..06fbc0fb 100644
--- a/docs/api/examples/post_vpcsvpcsidportsportidnio.txt
+++ b/docs/api/examples/post_vpcsvpcsidportsportidnio.txt
@@ -1,22 +1,25 @@
-curl -i -xPOST 'http://localhost:8000/vpcs/{vpcs_id}/ports/{port_id}/nio' -d '{"local_file": "/tmp/test", "remote_file": "/tmp/remote", "type": "nio_unix"}'
+curl -i -xPOST 'http://localhost:8000/vpcs/{vpcs_id}/ports/{port_id}/nio' -d '{"lport": 4242, "rhost": "127.0.0.1", "rport": 4343, "type": "nio_udp"}'
 
 POST /vpcs/{vpcs_id}/ports/{port_id}/nio HTTP/1.1
 {
-    "local_file": "/tmp/test",
-    "remote_file": "/tmp/remote",
-    "type": "nio_unix"
+    "lport": 4242,
+    "rhost": "127.0.0.1",
+    "rport": 4343,
+    "type": "nio_udp"
 }
 
 
-HTTP/1.1 404
+HTTP/1.1 200
 CONNECTION: close
-CONTENT-LENGTH: 59
+CONTENT-LENGTH: 89
 CONTENT-TYPE: application/json
 DATE: Thu, 08 Jan 2015 16:09:15 GMT
 SERVER: Python/3.4 aiohttp/0.13.1
 X-ROUTE: /vpcs/{vpcs_id}/ports/{port_id}/nio
 
 {
-    "message": "ID 42 doesn't exist",
-    "status": 404
+    "lport": 4242,
+    "rhost": "127.0.0.1",
+    "rport": 4343,
+    "type": "nio_udp"
 }
diff --git a/gns3server/handlers/vpcs_handler.py b/gns3server/handlers/vpcs_handler.py
index 6fc3495e..b12383b5 100644
--- a/gns3server/handlers/vpcs_handler.py
+++ b/gns3server/handlers/vpcs_handler.py
@@ -19,7 +19,7 @@
 from ..web.route import Route
 from ..schemas.vpcs import VPCS_CREATE_SCHEMA
 from ..schemas.vpcs import VPCS_OBJECT_SCHEMA
-from ..schemas.vpcs import VPCS_ADD_NIO_SCHEMA
+from ..schemas.vpcs import VPCS_NIO_SCHEMA
 from ..modules.vpcs import VPCS
 
 
@@ -48,7 +48,8 @@ class VPCSHandler(object):
             "vpcs_id": "Id of VPCS instance"
         },
         status_codes={
-            201: "Success of creation of VPCS",
+            200: "Success of starting VPCS",
+            404: "If VPCS doesn't exist"
         },
         description="Start VPCS",
         )
@@ -64,7 +65,8 @@ class VPCSHandler(object):
             "vpcs_id": "Id of VPCS instance"
         },
         status_codes={
-            201: "Success of stopping VPCS",
+            200: "Success of stopping VPCS",
+            404: "If VPCS doesn't exist"
         },
         description="Stop VPCS",
         )
@@ -81,17 +83,17 @@ class VPCSHandler(object):
         },
         status_codes={
             201: "Success of creation of NIO",
-            409: "Conflict"
+            404: "If VPCS doesn't exist"
         },
         description="ADD NIO to a VPCS",
-        input=VPCS_ADD_NIO_SCHEMA)
+        input=VPCS_NIO_SCHEMA,
+        output=VPCS_NIO_SCHEMA)
     def create_nio(request, response):
-        # TODO: raise 404 if VPCS not found GET VM can raise an exeption
         # TODO: response with nio
         vpcs_manager = VPCS.instance()
         vm = vpcs_manager.get_vm(int(request.match_info['vpcs_id']))
-        vm.port_add_nio_binding(int(request.match_info['port_id']), request.json)
+        nio = vm.port_add_nio_binding(int(request.match_info['port_id']), request.json)
 
-        response.json({'name': "PC 2", "vpcs_id": 42, "console": 4242})
+        response.json(nio)
 
 
diff --git a/gns3server/modules/base_manager.py b/gns3server/modules/base_manager.py
index ab07f427..36d031a6 100644
--- a/gns3server/modules/base_manager.py
+++ b/gns3server/modules/base_manager.py
@@ -39,7 +39,7 @@ class BaseManager:
         :returns: instance of Manager
         """
 
-        if not hasattr(cls, "_instance"):
+        if not hasattr(cls, "_instance") or cls._instance is None:
             cls._instance = cls()
         return cls._instance
 
diff --git a/gns3server/modules/vpcs/nios/nio_tap.py b/gns3server/modules/vpcs/nios/nio_tap.py
index 4c3ed6b2..39923a01 100644
--- a/gns3server/modules/vpcs/nios/nio_tap.py
+++ b/gns3server/modules/vpcs/nios/nio_tap.py
@@ -44,3 +44,6 @@ class NIO_TAP(object):
     def __str__(self):
 
         return "NIO TAP"
+
+    def __json__(self):
+        return {"type": "nio_tap", "tap_device": self._tap_device}
diff --git a/gns3server/modules/vpcs/nios/nio_udp.py b/gns3server/modules/vpcs/nios/nio_udp.py
index 0527f675..cca313e7 100644
--- a/gns3server/modules/vpcs/nios/nio_udp.py
+++ b/gns3server/modules/vpcs/nios/nio_udp.py
@@ -70,3 +70,6 @@ class NIO_UDP(object):
     def __str__(self):
 
         return "NIO UDP"
+
+    def __json__(self):
+        return {"type": "nio_udp", "lport": self._lport, "rport": self._rport, "rhost": self._rhost}
diff --git a/gns3server/modules/vpcs/vpcs_device.py b/gns3server/modules/vpcs/vpcs_device.py
index 5384a985..fe079c25 100644
--- a/gns3server/modules/vpcs/vpcs_device.py
+++ b/gns3server/modules/vpcs/vpcs_device.py
@@ -265,7 +265,6 @@ class VPCSDevice(BaseVM):
             nio = NIO_UDP(lport, rhost, rport)
         elif nio_settings["type"] == "nio_tap":
             tap_device = nio_settings["tap_device"]
-            print(has_privileged_access)
             if not has_privileged_access(self._path):
                 raise VPCSError("{} has no privileged access to {}.".format(self._path, tap_device))
             nio = NIO_TAP(tap_device)
diff --git a/gns3server/schemas/vpcs.py b/gns3server/schemas/vpcs.py
index dc5ca6dd..27a5bcd3 100644
--- a/gns3server/schemas/vpcs.py
+++ b/gns3server/schemas/vpcs.py
@@ -42,7 +42,7 @@ VPCS_CREATE_SCHEMA = {
 }
 
 
-VPCS_ADD_NIO_SCHEMA = {
+VPCS_NIO_SCHEMA = {
     "$schema": "http://json-schema.org/draft-04/schema#",
     "description": "Request validation to add a NIO for a VPCS instance",
     "type": "object",
diff --git a/gns3server/web/response.py b/gns3server/web/response.py
index 325455f4..d829e725 100644
--- a/gns3server/web/response.py
+++ b/gns3server/web/response.py
@@ -18,7 +18,9 @@
 import json
 import jsonschema
 import aiohttp.web
+import logging
 
+log = logging.getLogger(__name__)
 
 class Response(aiohttp.web.Response):
 
@@ -29,13 +31,22 @@ class Response(aiohttp.web.Response):
         headers['X-Route'] = self._route
         super().__init__(headers=headers, **kwargs)
 
+    """
+    Set the response content type to application/json and serialize
+    the content.
+
+    :param anwser The response as a Python object
+    """
     def json(self, answer):
         """Pass a Python object and return a JSON as answer"""
 
         self.content_type = "application/json"
+        if hasattr(answer, '__json__'):
+            answer = answer.__json__()
         if self._output_schema is not None:
             try:
                 jsonschema.validate(answer, self._output_schema)
             except jsonschema.ValidationError as e:
+                log.error("Invalid output schema")
                 raise aiohttp.web.HTTPBadRequest(text="{}".format(e))
         self.body = json.dumps(answer, indent=4, sort_keys=True).encode('utf-8')
diff --git a/gns3server/web/route.py b/gns3server/web/route.py
index 1687cde9..e55edf06 100644
--- a/gns3server/web/route.py
+++ b/gns3server/web/route.py
@@ -19,6 +19,9 @@ import json
 import jsonschema
 import asyncio
 import aiohttp
+import logging
+
+log = logging.getLogger(__name__)
 
 from ..modules.vm_error import VMError
 from .response import Response
@@ -37,6 +40,7 @@ def parse_request(request, input_schema):
     try:
         jsonschema.validate(request.json, input_schema)
     except jsonschema.ValidationError as e:
+        log.error("Invalid input schema")
         raise aiohttp.web.HTTPBadRequest(text="Request is not {} '{}' in schema: {}".format(
             e.validator,
             e.validator_value,
diff --git a/tests/api/test_version.py b/tests/api/test_version.py
index a052bb43..8fb46174 100644
--- a/tests/api/test_version.py
+++ b/tests/api/test_version.py
@@ -21,7 +21,7 @@ It's also used for unittest the HTTP implementation.
 """
 
 from tests.utils import asyncio_patch
-from tests.api.base import server, loop
+from tests.api.base import server, loop, port_manager
 from gns3server.version import __version__
 
 
diff --git a/tests/api/test_vpcs.py b/tests/api/test_vpcs.py
index eb65610f..623e1b65 100644
--- a/tests/api/test_vpcs.py
+++ b/tests/api/test_vpcs.py
@@ -15,6 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from unittest.mock import patch
 from tests.api.base import server, loop, port_manager
 from tests.utils import asyncio_patch
 from gns3server import modules
@@ -29,13 +30,26 @@ def test_vpcs_create(server):
     assert response.json['vpcs_id'] == 84
 
 
-def test_vpcs_nio_create(server):
-    response = server.post('/vpcs/42/ports/0/nio', {
-            'type': 'nio_unix',
-            'local_file': '/tmp/test',
-            'remote_file': '/tmp/remote'
+def test_vpcs_nio_create_udp(server):
+    vm = server.post('/vpcs', {'name': 'PC TEST 1'})
+    response = server.post('/vpcs/{}/ports/0/nio'.format(vm.json["vpcs_id"]), {
+            'type': 'nio_udp',
+            'lport': 4242,
+            'rport': 4343,
+            'rhost': '127.0.0.1'
         },
         example=True)
     assert response.status == 200
     assert response.route == '/vpcs/{vpcs_id}/ports/{port_id}/nio'
-    assert response.json['name'] == 'PC 2'
+    assert response.json['type'] == 'nio_udp'
+
+@patch("gns3server.modules.vpcs.vpcs_device.has_privileged_access", return_value=True)
+def test_vpcs_nio_create_tap(mock, server):
+    vm = server.post('/vpcs', {'name': 'PC TEST 1'})
+    response = server.post('/vpcs/{}/ports/0/nio'.format(vm.json["vpcs_id"]), {
+            'type': 'nio_tap',
+            'tap_device': 'test',
+        })
+    assert response.status == 200
+    assert response.route == '/vpcs/{vpcs_id}/ports/{port_id}/nio'
+    assert response.json['type'] == 'nio_tap'