diff --git a/Vagrantfile b/Vagrantfile
old mode 100644
new mode 100755
diff --git a/ansible/install.yml b/ansible/install.yml
index fd3aa4b..4e4ff01 100755
--- a/ansible/install.yml
+++ b/ansible/install.yml
@@ -57,8 +57,8 @@
    - name: install requests
      pip: name=requests state=latest
 
-   - name: install docker-py
-     pip: name=docker-py version=1.7.1
+   - name: install docker
+     pip: name=docker version=2.0.2
 
    - name: install prometheus_client
      pip: name=prometheus_client state=latest
diff --git a/misc/son-monitor/skewmon/Dockerfile b/misc/son-monitor/skewmon/Dockerfile
new file mode 100755
index 0000000..875708d
--- /dev/null
+++ b/misc/son-monitor/skewmon/Dockerfile
@@ -0,0 +1,10 @@
+FROM python:3-onbuild
+
+#periods in milliseconds
+ENV SAMPLE_PERIOD 10
+ENV TOTAL_PERIOD 2000
+
+ADD requirements.txt .
+ADD skewmon.py .
+
+CMD [ "python", "./skewmon.py" ]
\ No newline at end of file
diff --git a/misc/son-monitor/skewmon/requirements.txt b/misc/son-monitor/skewmon/requirements.txt
new file mode 100755
index 0000000..a73ea1c
--- /dev/null
+++ b/misc/son-monitor/skewmon/requirements.txt
@@ -0,0 +1 @@
+prometheus_client
\ No newline at end of file
diff --git a/misc/son-monitor/skewmon/skewmon.py b/misc/son-monitor/skewmon/skewmon.py
new file mode 100755
index 0000000..62384b1
--- /dev/null
+++ b/misc/son-monitor/skewmon/skewmon.py
@@ -0,0 +1,255 @@
+"""
+Copyright (c) 2015 SONATA-NFV and Paderborn University
+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.
+
+Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
+nor the names of its contributors may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+This work has been performed in the framework of the SONATA project,
+funded by the European Commission under Grant number 671517 through
+the Horizon 2020 and 5G-PPP programmes. The authors would like to
+acknowledge the contributions of their colleagues of the SONATA
+partner consortium (www.sonata-nfv.eu).
+"""
+
+"""
+Monitor the skewness of the resource usage probability distribution
+and export to a Prometheus Push Gateway
+(c) 2017 by Steven Van Rossem <steven.vanrossem@intec.ugent.be>
+"""
+
+#!/usr/bin/python3
+
+from time import sleep, time, perf_counter
+import math
+from prometheus_client import start_http_server, Summary, Histogram, Gauge, Counter, REGISTRY, CollectorRegistry, \
+    pushadd_to_gateway, push_to_gateway, delete_from_gateway
+import threading
+import os
+import json
+
+import logging
+LOG = logging.getLogger('skewmon')
+LOG.setLevel(level=logging.DEBUG)
+LOG.addHandler(logging.StreamHandler())
+
+
+# put env vars in Dockerfile
+PUSHGATEWAY_IP = '172.17.0.1'
+PUSHGATEWAY_PORT = 9091
+PUSHGATEWAY_ADDR = ':'.join([PUSHGATEWAY_IP, str(PUSHGATEWAY_PORT)])
+
+
+#general settings (ms)
+SAMPLE_PERIOD = int(os.environ['SAMPLE_PERIOD'])
+TOTAL_PERIOD = int(os.environ['TOTAL_PERIOD'])
+
+# define global variables
+registry = CollectorRegistry()
+exported_metric = Gauge('skewness', 'Skewness of docker vnf resource usage',
+                                              ['vnf_id', 'vnf_name', 'vnf_metric'], registry=registry)
+
+# find the VNFs to monitor
+# {metric_shortId: {VNF_NAME:<>,VNF_ID:<>,VNF_METRIC:<>}}
+
+def get_vnfs_to_monitor(config):
+    for key in config:
+        vnf_name = config[key].get('VNF_NAME')
+        vnf_id = config[key].get('VNF_ID')
+        vnf_metric = config[key].get('VNF_METRIC')
+        yield (vnf_id, vnf_name, vnf_metric)
+
+# export metric to the Prometheus PushGateway
+def export_metrics(key=None):
+    try:
+        pushadd_to_gateway(PUSHGATEWAY_ADDR, job='sonemu-skewmon', registry=registry, grouping_key=key)
+    except Exception as e:
+        LOG.warning("Pushgateway not reachable: {0}".format(str(e)))
+
+class skewness_monitor():
+    def __init__(self, docker_id, docker_name, metric):
+        # Prometheus metric to export
+        self.prom_skewness = exported_metric
+        self.docker_id = docker_id
+        self.docker_name = docker_name
+        self.vnf_metric = metric
+
+        # https://www.datadoghq.com/blog/how-to-collect-docker-metrics/
+        self.cpu_proc_file = '/sys/fs/cgroup/cpuacct/docker/{0}/cpuacct.usage'.format(self.docker_id)
+        self.mem_proc_file = '/sys/fs/cgroup/memory/docker/{0}/memory.usage_in_bytes'.format(self.docker_id)
+        metric_dict = {'cpu': self.cpu_proc_file,
+                       'mem': self.mem_proc_file}
+
+        self.proc_file = metric_dict[metric]
+
+        self.fp = open(self.proc_file)
+
+        #monitoring thread
+        self.export_thread = None
+        self.monitor_stop = threading.Event()
+
+    # get statistics with certain frequency and export skewness for further analysis
+    def _calc_skewness(self):
+
+        cpu_count0 = 0
+        time0 = 0
+
+        #milliseconds
+        stat_delta = SAMPLE_PERIOD
+        sample_T = TOTAL_PERIOD
+
+        data = []
+        n = 0
+
+        moment1 = 0
+        moment2 = 0
+        moment3 = 0
+
+        fp = self.fp
+
+        #collect samples
+        for n in range(0,round(sample_T/stat_delta)):
+            # first measurement
+            if cpu_count0 <= 0 or time0 <= 0:
+                time0 = perf_counter()
+                cpu_count0 = int(fp.read().strip())
+                fp.seek(0)
+                sleep(stat_delta/1000)
+                continue
+
+
+            #perf_counter in seconds
+            time1 = perf_counter()
+
+            # cpu count in nanoseconds
+            cpu_count1 = int(fp.read().strip())
+            fp.seek(0)
+
+            cpu_delta = cpu_count1 - cpu_count0
+            cpu_count0 = cpu_count1
+
+            time_delta = time1 - time0
+            time0 = time1
+
+            #work in nanoseconds
+            metric = (cpu_delta / (time_delta * 1e9))
+
+            data.append(metric)
+
+            #running calculation of sample moments
+            moment1 += metric
+            temp = metric * metric
+            moment2 += temp
+            moment3 += temp * metric
+
+
+            sleep(stat_delta/1000)
+
+        # calc skewness
+        M1 = (1 / n) * moment1
+        M2 = ((1 / n) * moment2) - M1**2
+        M3 = ((1 / n) * moment3) - (3 * M1 * ((1 / n) * moment2)) + (2 * M1**3)
+
+        s2 = (math.sqrt(n*(n - 1))/(n - 2)) * (M3 / (M2)**1.5)
+
+        LOG.info("docker_name: {0} metric: {1}".format(self.docker_name, self.vnf_metric))
+        LOG.info("Nsamples: {0}".format(n))
+        LOG.info("skewness: {0:.2f}".format(s2))
+        LOG.info("\n")
+
+        return s2
+
+    def _export_skewness_loop(self, stop_event):
+        #loop until flag is set
+        while(not stop_event.is_set()):
+            try:
+                skewness = self._calc_skewness()
+                self.prom_skewness.labels(vnf_id=self.docker_id, vnf_name=self.docker_name, vnf_metric=self.vnf_metric)\
+                    .set(skewness)
+            except ZeroDivisionError as e:
+                self.prom_skewness.labels(vnf_id=self.docker_id, vnf_name=self.docker_name, vnf_metric=self.vnf_metric) \
+                    .set(float('nan'))
+                LOG.warning("{1}: Skewness cannot be calculated: {0}".format(str(e), self.docker_name))
+            except Exception as e:
+                LOG.warning("Skewness cannot be calculated, stop thread: {0}".format(str(e)))
+                self.monitor_stop.set()
+
+        # if while has ended, monitoring thread will stop
+        self.prom_skewness.labels(vnf_id=self.docker_id, vnf_name=self.docker_name, vnf_metric=self.vnf_metric) \
+            .set(float('nan'))
+
+    #start the monitoring thread
+    def start(self):
+            if self.export_thread is not None:
+                LOG.warning('monitor thread is already running for: {0}'.format(self.docker_name))
+                return
+
+            self.export_thread = threading.Thread(target=self._export_skewness_loop, args=(self.monitor_stop,))
+            self.export_thread.start()
+            LOG.info('started thread: {0}'.format(self.docker_name))
+
+    #stop the monitoring thread
+    def stop(self):
+        self.monitor_stop.set()
+
+
+if __name__ == '__main__':
+
+    #started_vnfs {vnf_id:object}
+    vnfs_monitored = {}
+
+    # endless loop
+    while True:
+        #check config.txt for docker ids/names
+        configfile = open('/config.txt', 'r')
+        config = json.load(configfile)
+        vnfs_to_monitor = list(get_vnfs_to_monitor(config))
+
+        #for each new docker id in ENV start thread to monitor skewness
+        for vnf_id, vnf_name, vnf_metric in vnfs_to_monitor:
+            key = '_'.join([vnf_metric, vnf_id])
+            if key not in vnfs_monitored:
+                try:
+                    vnfs_monitored[key] = skewness_monitor(vnf_id, vnf_name, vnf_metric)
+                    vnfs_monitored[key].start()
+                except Exception as e:
+                    LOG.warning("Monitor cannot be started: {0}".format(str(e)))
+
+         #for each removed docker id ENV, stop export
+        for vnf_key in list(vnfs_monitored):
+            vnf_keys_to_monitor = ['_'.join([vnf_metric, vnf_id]) for vnf_id, vnf_name, vnf_metric in vnfs_to_monitor]
+            if vnf_key not in vnf_keys_to_monitor:
+                vnfs_monitored[vnf_key].stop()
+
+                vnf_name = vnfs_monitored[vnf_key].docker_name
+                vnf_metric, vnf_id = vnf_key.split('_')
+                LOG.info('stop monitored VNFs: {0}'.format(vnfs_monitored[vnf_key].docker_name))
+                del vnfs_monitored[vnf_key]
+
+                # remove metric with labels from registry
+                # (Push Gateway remembers last pushed value, so this is not so useful)
+                # collector = registry._names_to_collectors['skewness']
+                # if (vnf_id, vnf_name, vnf_metric) in collector._metrics:
+                #     collector.remove(vnf_id, vnf_name, vnf_metric)
+                delete_from_gateway(PUSHGATEWAY_ADDR, job='sonemu-skewmon')
+
+
+        #push to Prometheus gateway
+        export_metrics()
+        LOG.info('monitored VNFs: {0}'.format([monitor.docker_name for key, monitor in vnfs_monitored.items()]))
+        # wait before checking  again
+        sleep(TOTAL_PERIOD/1000)
\ No newline at end of file
diff --git a/misc/sonata-demo-service.son b/misc/sonata-demo-service.son
old mode 100644
new mode 100755
Binary files differ
diff --git a/setup-cli.py b/setup-cli.py
old mode 100644
new mode 100755
diff --git a/setup.py b/setup.py
index 0baad49..ce1c47f 100755
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@
           'pytest',
           'Flask',
           'flask_restful',
-          'docker-py==1.7.1',
+          'docker==2.0.2',
           'requests',
           'prometheus_client',
           'urllib3'
diff --git a/src/emuvim/api/rest/compute.py b/src/emuvim/api/rest/compute.py
index 22e9d6d..dc2b611 100755
--- a/src/emuvim/api/rest/compute.py
+++ b/src/emuvim/api/rest/compute.py
@@ -50,8 +50,13 @@
     """
     global dcs
 
-    def put(self, dc_label, compute_name):
+    def put(self, dc_label, compute_name, resource=None, value=None):
+        # check if resource update
+        if resource and value:
+           c = self._update_resource(dc_label, compute_name, resource, value)
+           return c.getStatus(), 200
 
+        # deploy new container
         # check if json data is a dict
         data = request.json
         if data is None:
@@ -74,6 +79,20 @@
             logging.exception("API error.")
             return ex.message, 500, CORS_HEADER
 
+    def _update_resource(self, dc_label, compute_name, resource, value):
+        #check if container exists
+        d = dcs.get(dc_label).net.getNodeByName(compute_name)
+        if resource == 'cpu':
+            cpu_period = int(dcs.get(dc_label).net.cpu_period)
+            cpu_quota = int(cpu_period * float(value))
+            #put default values back
+            if float(value) <= 0:
+                cpu_period = 100000
+                cpu_quota = -1
+            d.updateCpuLimit(cpu_period=cpu_period, cpu_quota=cpu_quota)
+        return d
+
+
     def get(self, dc_label, compute_name):
 
         logging.debug("API CALL: compute status")
diff --git a/src/emuvim/api/rest/monitor.py b/src/emuvim/api/rest/monitor.py
index 5558b87..6f99bdf 100755
--- a/src/emuvim/api/rest/monitor.py
+++ b/src/emuvim/api/rest/monitor.py
@@ -55,20 +55,26 @@
     """
     global net
 
-    def put(self, vnf_name, vnf_interface=None, metric='tx_packets'):
+    def put(self, vnf_name, vnf_interface=None, metric='tx_packets', cookie=None):
         logging.debug("REST CALL: start monitor VNF interface")
         try:
-            c = net.monitor_agent.setup_metric(vnf_name, vnf_interface, metric)
+            if cookie:
+                c = net.monitor_agent.setup_flow(vnf_name, vnf_interface, metric, cookie)
+            else:
+                c = net.monitor_agent.setup_metric(vnf_name, vnf_interface, metric)
             # return monitor message response
             return  str(c), 200, CORS_HEADER
         except Exception as ex:
             logging.exception("API error.")
             return ex.message, 500, CORS_HEADER
 
-    def delete(self, vnf_name, vnf_interface=None, metric='tx_packets'):
+    def delete(self, vnf_name, vnf_interface=None, metric='tx_packets', cookie=None):
         logging.debug("REST CALL: stop monitor VNF interface")
         try:
-            c = net.monitor_agent.stop_metric(vnf_name, vnf_interface, metric)
+            if cookie:
+                c = net.monitor_agent.stop_flow(vnf_name, vnf_interface, metric, cookie)
+            else:
+                c = net.monitor_agent.stop_metric(vnf_name, vnf_interface, metric)
             # return monitor message response
             return str(c), 200, CORS_HEADER
         except Exception as ex:
@@ -106,3 +112,140 @@
         except Exception as ex:
             logging.exception("API error.")
             return ex.message, 500, CORS_HEADER
+
+class MonitorLinkAction(Resource):
+    """
+    Add or remove flow monitoring on chains between VNFs.
+    These chain links are implemented as flow entries in the networks' SDN switches.
+    The monitoring is an extra flow entry on top of the existing chain, with a specific match. (preserving the chaining)
+    The counters of this new monitoring flow are exported
+    :param vnf_src_name: VNF name of the source of the link
+    :param vnf_dst_name: VNF name of the destination of the link
+    :param vnf_src_interface: VNF interface name of the source of the link
+    :param vnf_dst_interface: VNF interface name of the destination of the link
+    :param weight: weight of the link (can be useful for routing calculations)
+    :param match: OpenFlow match format of the flow entry
+    :param bidirectional: boolean value if the link needs to be implemented from src to dst and back
+    :param cookie: cookie value, identifier of the flow entry to be installed.
+    :param priority: integer indicating the priority of the flow entry
+    :param skip_vlan_tag: boolean to indicate whether a new vlan tag should be created for this chain
+    :param monitor: boolean to indicate whether a new vlan tag should be created for this chain
+    :param monitor_placement: 'tx'=place the monitoring flowrule at the beginning of the chain, 'rx'=place at the end of the chain
+    :param metric: tx_packet_rate, tx_byte_rate, rx_packet_rate, rx_byte_rate
+    :return: message string indicating if the chain action is succesful or not
+    """
+
+    # the global net is set from the topology file, and connected via connectDCNetwork function in rest_api_endpoint.py
+    global net
+
+    def put(self, vnf_src_name, vnf_dst_name):
+        logging.debug("REST CALL: monitor link flow add")
+
+        try:
+            command = 'add-flow'
+            return self._MonitorLinkAction(vnf_src_name, vnf_dst_name, command=command)
+        except Exception as ex:
+            logging.exception("API error.")
+            return ex.message, 500, CORS_HEADER
+
+    def delete(self, vnf_src_name, vnf_dst_name):
+        logging.debug("REST CALL: monitor link flow remove")
+
+        try:
+            command = 'del-flows'
+            return self._MonitorLinkAction(vnf_src_name, vnf_dst_name, command=command)
+        except Exception as ex:
+            logging.exception("API error.")
+            return ex.message, 500, CORS_HEADER
+
+    def _MonitorLinkAction(self, vnf_src_name, vnf_dst_name, command=None):
+        # call DCNetwork method, not really datacenter specific API for now...
+        # no check if vnfs are really connected to this datacenter...
+        try:
+            # check if json data is a dict
+            data = request.json
+            if data is None:
+                data = {}
+            elif type(data) is not dict:
+                data = json.loads(request.json)
+
+            vnf_src_interface = data.get("vnf_src_interface")
+            vnf_dst_interface = data.get("vnf_dst_interface")
+            weight = data.get("weight")
+            match = data.get("match")
+            bidirectional = data.get("bidirectional")
+            cookie = data.get("cookie")
+            priority = data.get("priority")
+            skip_vlan_tag = data.get("skip_vlan_tag")
+            monitor = data.get("monitor")
+            monitor_placement = data.get("monitor_placement")
+
+            #first install monitor flow
+            c1 = net.setChain(
+                vnf_src_name, vnf_dst_name,
+                vnf_src_interface=vnf_src_interface,
+                vnf_dst_interface=vnf_dst_interface,
+                cmd=command,
+                weight=weight,
+                match=match,
+                bidirectional=bidirectional,
+                cookie=cookie,
+                priority=priority,
+                skip_vlan_tag=skip_vlan_tag,
+                monitor=monitor,
+                monitor_placement=monitor_placement)
+
+            #then export monitor flow
+            metric = data.get("metric")
+            if 'rx' in monitor_placement:
+                vnf_name = vnf_dst_name
+                vnf_interface = vnf_dst_interface
+            elif 'tx' in monitor_placement:
+                vnf_name = vnf_src_name
+                vnf_interface = vnf_src_interface
+
+            c2 = 'command unknown'
+            if command == 'add-flow':
+                c2 = net.monitor_agent.setup_flow(vnf_name, vnf_interface, metric, cookie)
+            elif command == 'del-flows':
+                c2 = net.monitor_agent.stop_flow(vnf_name, vnf_interface, metric, cookie)
+
+            # return setChain response
+            return (str(c1) + " " + str(c2)), 200, CORS_HEADER
+        except Exception as ex:
+            logging.exception("API error.")
+            return ex.message, 500
+
+class MonitorSkewAction(Resource):
+    """
+    Monitor the counters of a VNF interface
+    :param vnf_name: name of the VNF to be monitored
+    :param resource: the resource to be monitored (cpu, mem, ...)
+    :return: message string indicating if the monitor action is succesful or not
+    """
+    global net
+
+    def put(self, vnf_name, resource_name='cpu'):
+        logging.debug("REST CALL: start monitor skewness")
+        try:
+            # configure skewmon
+            c = net.monitor_agent.update_skewmon(vnf_name, resource_name, action='start')
+
+            # return monitor message response
+            return  str(c), 200
+        except Exception as ex:
+            logging.exception("API error.")
+            return ex.message, 500
+
+    def delete(self, vnf_name, resource_name='cpu'):
+        logging.debug("REST CALL: stop monitor skewness")
+        try:
+            # configure skewmon
+            c = net.monitor_agent.update_skewmon(vnf_name, resource_name, action='stop')
+
+            # return monitor message response
+            return str(c), 200, CORS_HEADER
+        except Exception as ex:
+            logging.exception("API error.")
+            return ex.message, 500, CORS_HEADER
+
diff --git a/src/emuvim/api/rest/network.py b/src/emuvim/api/rest/network.py
index 2745602..c4ab23f 100755
--- a/src/emuvim/api/rest/network.py
+++ b/src/emuvim/api/rest/network.py
@@ -38,9 +38,9 @@
 import json
 
 logging.basicConfig(level=logging.INFO)
-
 CORS_HEADER = {'Access-Control-Allow-Origin': '*'}
 
+# the global net is set from the topology file, and connected via connectDCNetwork function in rest_api_endpoint.py
 net = None
 
 
@@ -56,6 +56,9 @@
     :param bidirectional: boolean value if the link needs to be implemented from src to dst and back
     :param cookie: cookie value, identifier of the flow entry to be installed.
     :param priority: integer indicating the priority of the flow entry
+    :param skip_vlan_tag: boolean to indicate whether a new vlan tag should be created for this chain
+    :param monitor: boolean to indicate whether a new vlan tag should be created for this chain
+    :param monitor_placement: 'tx'=place the monitoring flowrule at the beginning of the chain, 'rx'=place at the end of the chain
     :return: message string indicating if the chain action is succesful or not
     """
 
@@ -89,6 +92,10 @@
             bidirectional = data.get("bidirectional")
             cookie = data.get("cookie")
             priority = data.get("priority")
+            skip_vlan_tag = data.get("skip_vlan_tag")
+            monitor = data.get("monitor")
+            monitor_placement = data.get("monitor_placement")
+
             c = net.setChain(
                 vnf_src_name, vnf_dst_name,
                 vnf_src_interface=vnf_src_interface,
@@ -98,7 +105,10 @@
                 match=match,
                 bidirectional=bidirectional,
                 cookie=cookie,
-                priority=priority)
+                priority=priority,
+                skip_vlan_tag=skip_vlan_tag,
+                monitor=monitor,
+                monitor_placement=monitor_placement)
             # return setChain response
             return str(c), 200, CORS_HEADER
         except Exception as ex:
diff --git a/src/emuvim/api/rest/rest_api_endpoint.py b/src/emuvim/api/rest/rest_api_endpoint.py
index e382f5a..7168f37 100755
--- a/src/emuvim/api/rest/rest_api_endpoint.py
+++ b/src/emuvim/api/rest/rest_api_endpoint.py
@@ -39,7 +39,7 @@
 from network import NetworkAction
 
 import monitor
-from monitor import MonitorInterfaceAction, MonitorFlowAction
+from monitor import MonitorInterfaceAction, MonitorFlowAction, MonitorLinkAction, MonitorSkewAction
 
 logging.basicConfig(level=logging.INFO)
 
@@ -61,7 +61,10 @@
 
         # setup endpoints
 
-        self.api.add_resource(Compute, "/restapi/compute/<dc_label>/<compute_name>")
+        # compute related actions (start/stop VNFs, get info)
+        self.api.add_resource(Compute,
+                              "/restapi/compute/<dc_label>/<compute_name>",
+                              "/restapi/compute/<dc_label>/<compute_name>/<resource>/<value>")
         self.api.add_resource(ComputeList,
                       "/restapi/compute",
                       "/restapi/compute/<dc_label>")
@@ -69,14 +72,30 @@
         self.api.add_resource(DatacenterStatus, "/restapi/datacenter/<dc_label>")
         self.api.add_resource(DatacenterList, "/restapi/datacenter")
 
-        self.api.add_resource(NetworkAction, "/restapi/network/<vnf_src_name>/<vnf_dst_name>", )
 
+        # network related actions (setup chaining between VNFs)
+        self.api.add_resource(NetworkAction,
+                              "/restapi/network/<vnf_src_name>/<vnf_dst_name>")
+
+
+        # monitoring related actions
+        # export a network interface traffic rate counter
         self.api.add_resource(MonitorInterfaceAction,
-                              "/restapi/monitor/<vnf_name>/<metric>",
-                              "/restapi/monitor/<vnf_name>/<vnf_interface>/<metric>")
+                              "/restapi/monitor/interface/<vnf_name>/<metric>",
+                              "/restapi/monitor/interface/<vnf_name>/<vnf_interface>/<metric>",
+                              "/restapi/monitor/interface/<vnf_name>/<vnf_interface>/<metric>/<cookie>")
+        # export flow traffic counter, of a manually pre-installed flow entry, specified by its cookie
         self.api.add_resource(MonitorFlowAction,
-                              "/restapi/flowmon/<vnf_name>/<metric>/<cookie>",
-                              "/restapi/flowmon/<vnf_name>/<vnf_interface>/<metric>/<cookie>")
+                              "/restapi/monitor/flow/<vnf_name>/<metric>/<cookie>",
+                              "/restapi/monitor/flow/<vnf_name>/<vnf_interface>/<metric>/<cookie>")
+        # install monitoring of a specific flow on a pre-existing link in the service.
+        # the traffic counters of the newly installed monitor flow are exported
+        self.api.add_resource(MonitorLinkAction,
+                              "/restapi/monitor/link/<vnf_src_name>/<vnf_dst_name>")
+        # install skewness monitor of resource usage disribution
+        # the skewness metric is exported
+        self.api.add_resource(MonitorSkewAction,
+                              "/restapi/monitor/skewness/<vnf_name>/<resource_name>")
 
         logging.debug("Created API endpoint %s(%s:%d)" % (self.__class__.__name__, self.ip, self.port))
 
diff --git a/src/emuvim/api/sonata/dummygatekeeper.py b/src/emuvim/api/sonata/dummygatekeeper.py
index 4018b69..f9ff506 100755
--- a/src/emuvim/api/sonata/dummygatekeeper.py
+++ b/src/emuvim/api/sonata/dummygatekeeper.py
@@ -39,11 +39,12 @@
 import zipfile
 import yaml
 import threading
-from docker import Client as DockerClient
+from docker import DockerClient, APIClient
 from flask import Flask, request
 import flask_restful as fr
 from collections import defaultdict
 import pkg_resources
+from subprocess import Popen
 
 logging.basicConfig()
 LOG = logging.getLogger("sonata-dummy-gatekeeper")
@@ -75,6 +76,7 @@
     def __init__(self):
         self.services = dict()
         self.dcs = dict()
+        self.net = None
         self.vnf_counter = 0  # used to generate short names for VNFs (Mininet limitation)
         LOG.info("Create SONATA dummy gatekeeper.")
 
@@ -181,6 +183,9 @@
             eline_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-Line")]
             elan_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-LAN")]
 
+            GK.net.deployed_elines.extend(eline_fwd_links)
+            GK.net.deployed_elans.extend(elan_fwd_links)
+
             # 4a. deploy E-Line links
             # cookie is used as identifier for the flowrules installed by the dummygatekeeper
             # eg. different services get a unique cookie for their flowrules
@@ -228,6 +233,9 @@
             # 4b. deploy E-LAN links
             base = 10
             for link in elan_fwd_links:
+
+                elan_vnf_list=[]
+
                 # generate lan ip address
                 ip = 1
                 for intf in link["connection_points_reference"]:
@@ -236,6 +244,8 @@
                     if vnf_id in self.sap_identifiers:
                         src_docker_name = "{0}_{1}".format(vnf_id, intf_name)
                         vnf_id = src_docker_name
+                    else:
+                        src_docker_name = vnf_id
                     vnf_name = vnf_id2vnf_name[vnf_id]
                     LOG.debug(
                         "Setting up E-LAN link. %s(%s:%s) -> %s" % (
@@ -250,6 +260,14 @@
                             self._vnf_reconfigure_network(vnfi, intf_name, ip_address)
                             # increase for the next ip address on this E-LAN
                             ip += 1
+
+                            # add this vnf and interface to the E-LAN for tagging
+                            network = self.vnfds[vnf_name].get("dc").net  # there should be a cleaner way to find the DCNetwork
+                            elan_vnf_list.append({'name':src_docker_name,'interface':intf_name})
+
+
+                # install the VLAN tags for this E-LAN
+                network.setLAN(elan_vnf_list)
                 # increase the base ip address for the next E-LAN
                 base += 1
 
@@ -436,6 +454,7 @@
                 self.package_content_path,
                 make_relative_path(self.manifest.get("entry_service_template")))
             self.nsd = load_yaml(nsd_path)
+            GK.net.deployed_nsds.append(self.nsd)
             LOG.debug("Loaded NSD: %r" % self.nsd.get("name"))
 
     def _load_vnfd(self):
@@ -524,12 +543,22 @@
         dc = DockerClient()
         for url in self.remote_docker_image_urls.itervalues():
             if not FORCE_PULL:  # only pull if not present (speedup for development)
-                if len(dc.images(name=url)) > 0:
+                if len(dc.images.list(name=url)) > 0:
                     LOG.debug("Image %r present. Skipping pull." % url)
                     continue
             LOG.info("Pulling image: %r" % url)
-            dc.pull(url,
-                    insecure_registry=True)
+            # this seems to fail with latest docker api version 2.0.2
+            # dc.images.pull(url,
+            #        insecure_registry=True)
+            #using docker cli instead
+            cmd = ["docker",
+                   "pull",
+                   url,
+                   ]
+            Popen(cmd).wait()
+
+
+
 
     def _check_docker_image_exists(self, image_name):
         """
@@ -537,7 +566,7 @@
         :param image_name: name of the docker image
         :return:
         """
-        return len(DockerClient().images(image_name)) > 0
+        return len(DockerClient().images.list(name=image_name)) > 0
 
     def _calculate_placement(self, algorithm):
         """
@@ -747,6 +776,7 @@
 
 def start_rest_api(host, port, datacenters=dict()):
     GK.dcs = datacenters
+    GK.net = get_dc_network()
     # start the Flask server (not the best performance but ok for our use case)
     app.run(host=host,
             port=port,
@@ -795,6 +825,14 @@
         r.append("%d.0.0.%d/%d" % (i, ip, subnet_size))
     return r
 
+def get_dc_network():
+    """
+    retrieve the DCnetwork where this dummygatekeeper (GK) connects to.
+    Assume at least 1 datacenter is connected to this GK, and that all datacenters belong to the same DCNetwork
+    :return:
+    """
+    assert (len(GK.dcs) > 0)
+    return GK.dcs.values()[0].net
 
 if __name__ == '__main__':
     """
diff --git a/src/emuvim/api/sonata/sap_vnfd.yml b/src/emuvim/api/sonata/sap_vnfd.yml
old mode 100644
new mode 100755
diff --git a/src/emuvim/cli/rest/compute.py b/src/emuvim/cli/rest/compute.py
index b92fd4f..9e5e0ab 100755
--- a/src/emuvim/cli/rest/compute.py
+++ b/src/emuvim/cli/rest/compute.py
@@ -30,6 +30,7 @@
 import pprint
 import argparse
 import json
+from subprocess import Popen
 
 pp = pprint.PrettyPrinter(indent=4)
 
@@ -77,18 +78,21 @@
             if len(c) > 1:
                 name = c[0]
                 status = c[1]
-                eth0ip = status.get("docker_network", "-")
+                #eth0ip = status.get("docker_network", "-")
+                netw_list = [netw_dict['intf_name'] for netw_dict in status.get("network")]
+                dc_if_list = [netw_dict['dc_portname'] for netw_dict in status.get("network")]
                 table.append([status.get("datacenter"),
                               name,
                               status.get("image"),
-                              eth0ip,
-                              status.get("state").get("Status")])
+                              ','.join(netw_list),
+                              ','.join(dc_if_list)])
+                #status.get("state").get("Status")]
 
         headers = ["Datacenter",
                    "Container",
                    "Image",
-                   "docker0",
-                   "Status"]
+                   "Interface list",
+                   "Datacenter interfaces"]
         print(tabulate(table, headers=headers, tablefmt="grid"))
 
     def status(self, args):
@@ -100,6 +104,11 @@
 
         pp.pprint(list)
 
+    def xterm(self, args):
+        vnf_names = args.get("vnf_names")
+        for vnf_name in vnf_names:
+            Popen(['xterm', '-xrm', 'XTerm.vt100.allowTitleOps: false', '-T', vnf_name,
+                   '-e', "docker exec -it mn.{0} /bin/bash".format(vnf_name)])
 
 parser = argparse.ArgumentParser(description="""son-emu compute
     
@@ -110,9 +119,13 @@
     """, formatter_class=argparse.RawTextHelpFormatter)
 parser.add_argument(
     "command",
-    choices=['start', 'stop', 'list', 'status'],
+    choices=['start', 'stop', 'list', 'status', 'xterm'],
     help="Action to be executed.")
 parser.add_argument(
+    "vnf_names",
+    nargs='*',
+    help="vnf names to open an xterm for")
+parser.add_argument(
     "--datacenter", "-d", dest="datacenter",
     help="Data center to which the command should be applied.")
 parser.add_argument(
diff --git a/src/emuvim/cli/rest/monitor.py b/src/emuvim/cli/rest/monitor.py
index 858aad7..7af1fbb 100755
--- a/src/emuvim/cli/rest/monitor.py
+++ b/src/emuvim/cli/rest/monitor.py
@@ -49,7 +49,7 @@
         vnf_name = self._parse_vnf_name(args.get("vnf_name"))
         vnf_interface = self._parse_vnf_interface(args.get("vnf_name"))
 
-        response = put("%s/restapi/monitor/%s/%s/%s" %
+        response = put("%s/restapi/monitor/interface/%s/%s/%s" %
                        (args.get("endpoint"),
                         vnf_name,
                         vnf_interface,
@@ -60,7 +60,7 @@
         vnf_name = self._parse_vnf_name(args.get("vnf_name"))
         vnf_interface = self._parse_vnf_interface(args.get("vnf_name"))
 
-        response = delete("%s/restapi/monitor/%s/%s/%s" %
+        response = delete("%s/restapi/monitor/interface/%s/%s/%s" %
                        (args.get("endpoint"),
                         vnf_name,
                         vnf_interface,
@@ -71,7 +71,7 @@
         vnf_name = self._parse_vnf_name(args.get("vnf_name"))
         vnf_interface = self._parse_vnf_interface(args.get("vnf_name"))
 
-        response = put("%s/restapi/monitor/%s/%s/%s/%s" %
+        response = put("%s/restapi/monitor/flow/%s/%s/%s/%s" %
                        (args.get("endpoint"),
                         vnf_name,
                         vnf_interface,
@@ -84,7 +84,7 @@
         vnf_name = self._parse_vnf_name(args.get("vnf_name"))
         vnf_interface = self._parse_vnf_interface(args.get("vnf_name"))
 
-        response = delete("%s/restapi/monitor/%s/%s/%s/%s" %
+        response = delete("%s/restapi/monitor/flow/%s/%s/%s/%s" %
                        (args.get("endpoint"),
                         vnf_name,
                         vnf_interface,
diff --git a/src/emuvim/dcemulator/monitoring.py b/src/emuvim/dcemulator/monitoring.py
index 9cf2a3b..d0e45da 100755
--- a/src/emuvim/dcemulator/monitoring.py
+++ b/src/emuvim/dcemulator/monitoring.py
@@ -36,7 +36,8 @@
 import threading
 from subprocess import Popen
 import os
-
+import docker
+import json
 
 logging.basicConfig(level=logging.INFO)
 
@@ -53,6 +54,7 @@
 class DCNetworkMonitor():
     def __init__(self, net):
         self.net = net
+        self.dockercli = docker.from_env()
 
         # pushgateway address
         self.pushgateway = 'localhost:{0}'.format(PUSHGATEWAY_PORT)
@@ -88,6 +90,7 @@
         self.monitor_flow_lock = threading.Lock()
         self.network_metrics = []
         self.flow_metrics = []
+        self.skewmon_metrics = {}
 
         # start monitoring thread
         self.start_monitoring = True
@@ -178,9 +181,10 @@
 
                 self.flow_metrics.remove(flow_dict)
 
-                for collector in self.registry._collectors:
-                    if (vnf_name, vnf_interface, cookie) in collector._metrics:
-                        collector.remove(vnf_name, vnf_interface, cookie)
+                # set metric to NaN
+                self.prom_metrics[flow_dict['metric_key']]. \
+                    labels(vnf_name=vnf_name, vnf_interface=vnf_interface, flow_id=cookie). \
+                    set(float('nan'))
 
                 delete_from_gateway(self.pushgateway, job='sonemu-SDNcontroller')
 
@@ -276,29 +280,11 @@
 
                 self.network_metrics.remove(metric_dict)
 
-                #this removes the complete metric, all labels...
-                #REGISTRY.unregister(self.prom_metrics[metric_dict['metric_key']])
-                #self.registry.unregister(self.prom_metrics[metric_dict['metric_key']])
-
-                for collector in self.registry._collectors :
-
-                    """
-                    INFO:root:name:sonemu_rx_count_packets
-                    labels:('vnf_name', 'vnf_interface')
-                    metrics:{(u'tsrc', u'output'): < prometheus_client.core.Gauge
-                    object
-                    at
-                    0x7f353447fd10 >}
-                    """
-                    logging.info('{0}'.format(collector._metrics.values()))
-
-                    if (vnf_name, vnf_interface, 'None') in collector._metrics:
-                        logging.info('2 name:{0} labels:{1} metrics:{2}'.format(collector._name, collector._labelnames,
-                                                                              collector._metrics))
-                        collector.remove(vnf_name, vnf_interface, 'None')
-
                 # set values to NaN, prometheus api currently does not support removal of metrics
                 #self.prom_metrics[metric_dict['metric_key']].labels(vnf_name, vnf_interface).set(float('nan'))
+                self.prom_metrics[metric_dict['metric_key']]. \
+                    labels(vnf_name=vnf_name, vnf_interface=vnf_interface, flow_id=None). \
+                    set(float('nan'))
 
                 # this removes the complete metric, all labels...
                 # 1 single monitor job for all metrics of the SDN controller
@@ -363,6 +349,13 @@
 
                 self.set_flow_metric(flow_dict, flow_stat_dict)
 
+
+            try:
+                if len(self.flow_metrics) > 0:
+                    pushadd_to_gateway(self.pushgateway, job='sonemu-SDNcontroller', registry=self.registry)
+            except Exception, e:
+                logging.warning("Pushgateway not reachable: {0} {1}".format(Exception, e))
+
             self.monitor_flow_lock.release()
             time.sleep(1)
 
@@ -392,6 +385,12 @@
                 for metric_dict in metric_list:
                     self.set_network_metric(metric_dict, port_stat_dict)
 
+            try:
+                if len(self.network_metrics) > 0:
+                    pushadd_to_gateway(self.pushgateway, job='sonemu-SDNcontroller', registry=self.registry)
+            except Exception, e:
+                logging.warning("Pushgateway not reachable: {0} {1}".format(Exception, e))
+
             self.monitor_lock.release()
             time.sleep(1)
 
@@ -413,12 +412,9 @@
 
                 # set prometheus metric
                 self.prom_metrics[metric_dict['metric_key']].\
-                    labels({'vnf_name': vnf_name, 'vnf_interface': vnf_interface, 'flow_id': None}).\
+                    labels(vnf_name=vnf_name, vnf_interface=vnf_interface, flow_id=None).\
                     set(this_measurement)
 
-                # 1 single monitor job for all metrics of the SDN controller
-                pushadd_to_gateway(self.pushgateway, job='sonemu-SDNcontroller', registry=self.registry)
-
                 # also the rate is calculated here, but not used for now
                 # (rate can be easily queried from prometheus also)
                 if previous_monitor_time <= 0 or previous_monitor_time >= port_uptime:
@@ -465,13 +461,8 @@
         #flow_uptime = flow_stat['duration_sec'] + flow_stat['duration_nsec'] * 10 ** (-9)
 
         self.prom_metrics[metric_dict['metric_key']]. \
-            labels({'vnf_name': vnf_name, 'vnf_interface': vnf_interface, 'flow_id': cookie}). \
+            labels(vnf_name=vnf_name, vnf_interface=vnf_interface, flow_id=cookie). \
             set(counter)
-        try:
-            pushadd_to_gateway(self.pushgateway, job='sonemu-SDNcontroller', registry=self.registry)
-        except Exception, e:
-            logging.warning("Pushgateway not reachable: {0} {1}".format(Exception, e))
-
 
     def start_Prometheus(self, port=9090):
         # prometheus.yml configuration file is located in the same directory as this file
@@ -523,23 +514,13 @@
         self.monitor_flow_thread.join()
 
         # these containers are used for monitoring but are started now outside of son-emu
-        '''
-        if self.prometheus_process is not None:
-            logging.info('stopping prometheus container')
-            self.prometheus_process.terminate()
-            self.prometheus_process.kill()
-            self._stop_container('prometheus')
-        '''
+
         if self.pushgateway_process is not None:
             logging.info('stopping pushgateway container')
-            #self.pushgateway_process.terminate()
-            #self.pushgateway_process.kill()
             self._stop_container('pushgateway')
 
         if self.cadvisor_process is not None:
             logging.info('stopping cadvisor container')
-            #self.cadvisor_process.terminate()
-            #self.cadvisor_process.kill()
             self._stop_container('cadvisor')
 
     def switch_tx_rx(self,metric=''):
@@ -554,9 +535,74 @@
 
     def _stop_container(self, name):
 
-        cmd = ["docker",
-               "rm",
-               "-f",
-               name]
-        Popen(cmd).wait()
+        container = self.dockercli.containers.get(name)
+        container.remove(force=True)
+
+    def update_skewmon(self, vnf_name, resource_name, action):
+
+        ret = ''
+
+        config_file_path = '/tmp/skewmon.cfg'
+        configfile = open(config_file_path, 'a+')
+        try:
+            config = json.load(configfile)
+        except:
+            #not a valid json file or empty
+            config = {}
+
+        #initialize config file
+        if len(self.skewmon_metrics) == 0:
+            config = {}
+        json.dump(config, configfile)
+        configfile.close()
+
+        docker_name = 'mn.' + vnf_name
+        vnf_container = self.dockercli.containers.get(docker_name)
+        key = resource_name + '_' + vnf_container.short_id
+        vnf_id = vnf_container.id
+
+        if action == 'start':
+            # add a new vnf to monitor
+            config[key] = dict(VNF_NAME=vnf_name,
+                                VNF_ID=vnf_id,
+                                VNF_METRIC=resource_name)
+            ret = 'adding to skewness monitor: {0} {1} '.format(vnf_name, resource_name)
+            logging.info(ret)
+        elif action == 'stop':
+            # remove vnf to monitor
+            config.pop(key)
+            ret = 'removing from skewness monitor: {0} {1} '.format(vnf_name, resource_name)
+            logging.info(ret)
+
+        self.skewmon_metrics = config
+        configfile = open(config_file_path, 'w')
+        json.dump(config, configfile)
+        configfile.close()
+
+        try:
+            skewmon_container = self.dockercli.containers.get('skewmon')
+
+            # remove container if config is empty
+            if len(config) == 0:
+                ret += 'stopping skewness monitor'
+                logging.info('stopping skewness monitor')
+                skewmon_container.remove(force=True)
+
+        except docker.errors.NotFound:
+            # start container if not running
+            ret += 'starting skewness monitor'
+            logging.info('starting skewness monitor')
+            volumes = {'/sys/fs/cgroup':{'bind':'/sys/fs/cgroup', 'mode':'ro'},
+                       '/tmp/skewmon.cfg':{'bind':'/config.txt', 'mode':'ro'}}
+            self.dockercli.containers.run('skewmon',
+                                          detach=True,
+                                          volumes=volumes,
+                                          labels=['com.containernet'],
+                                          name='skewmon'
+                                          )
+        return ret
+
+
+
+
 
diff --git a/src/emuvim/dcemulator/net.py b/src/emuvim/dcemulator/net.py
index a08a9e1..1a8d938 100755
--- a/src/emuvim/dcemulator/net.py
+++ b/src/emuvim/dcemulator/net.py
@@ -32,6 +32,7 @@
 from subprocess import Popen
 import re
 import requests
+import os
 
 from mininet.net import Containernet
 from mininet.node import Controller, DefaultController, OVSSwitch, OVSKernelSwitch, Docker, RemoteController
@@ -46,6 +47,9 @@
 LOG = logging.getLogger("dcemulator.net")
 LOG.setLevel(logging.DEBUG)
 
+# default CPU period used for cpu percentage-based cfs values (microseconds)
+CPU_PERIOD = 1000000
+
 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides
@@ -55,7 +59,7 @@
     """
 
     def __init__(self, controller=RemoteController, monitor=False,
-                 enable_learning = True,   # in case of RemoteController (Ryu), learning switch behavior can be turned off/on
+                 enable_learning=False, # learning switch behavior of the default ovs switches icw Ryu controller can be turned off/on, needed for E-LAN functionality
                  dc_emulation_max_cpu=1.0,  # fraction of overall CPU time for emulation
                  dc_emulation_max_mem=512,  # emulation max mem in MB
                  **kwargs):
@@ -68,6 +72,12 @@
         # members
         self.dcs = {}
         self.ryu_process = None
+        #list of deployed nsds.E_Lines and E_LANs (uploaded from the dummy gatekeeper)
+        self.deployed_nsds = []
+        self.deployed_elines = []
+        self.deployed_elans = []
+        self.installed_chains = []
+
 
         # always cleanup environment before we start the emulator
         self.killRyu()
@@ -77,10 +87,18 @@
         Containernet.__init__(
             self, switch=OVSKernelSwitch, controller=controller, **kwargs)
 
+        # default switch configuration
+        enable_ryu_learning = False
+        if enable_learning :
+            self.failMode = 'standalone'
+            enable_ryu_learning = True
+        else:
+            self.failMode = 'secure'
+
         # Ryu management
         if controller == RemoteController:
             # start Ryu controller
-            self.startRyu(learning_switch=enable_learning)
+            self.startRyu(learning_switch=enable_ryu_learning)
 
         # add the specified controller
         self.addController('c0', controller=controller)
@@ -106,6 +124,7 @@
         # initialize resource model registrar
         self.rm_registrar = ResourceModelRegistrar(
             dc_emulation_max_cpu, dc_emulation_max_mem)
+        self.cpu_period = CPU_PERIOD
 
     def addDatacenter(self, label, metadata={}, resource_log_path=None):
         """
@@ -127,7 +146,7 @@
         """
         assert node1 is not None
         assert node2 is not None
-        LOG.debug("addLink: n1=%s n2=%s" % (str(node1), str(node2)))
+
         # ensure type of node1
         if isinstance( node1, basestring ):
             if node1 in self.dcs:
@@ -205,6 +224,9 @@
         attr_dict2.update(attr_dict)
         self.DCNetwork_graph.add_edge(node2.name, node1.name, attr_dict=attr_dict2)
 
+        LOG.debug("addLink: n1={0} intf1={1} -- n2={2} intf2={3}".format(
+            str(node1),node1_port_name, str(node2), node2_port_name))
+
         return link
 
     def addDocker( self, label, **params ):
@@ -225,9 +247,26 @@
         """
         Wrapper for addSwitch method to store switch also in graph.
         """
+
+        # add this switch to the global topology overview
         if add_to_graph:
             self.DCNetwork_graph.add_node(name)
-        return Containernet.addSwitch(self, name, protocols='OpenFlow10,OpenFlow12,OpenFlow13', **params)
+
+        # set the learning switch behavior
+        if 'failMode' in params :
+            failMode = params['failMode']
+        else :
+            failMode = self.failMode
+
+        s = Containernet.addSwitch(self, name, protocols='OpenFlow10,OpenFlow12,OpenFlow13', failMode=failMode, **params)
+
+        # set flow entry that enables learning switch behavior (needed to enable E-LAN functionality)
+        #LOG.info('failmode {0}'.format(failMode))
+        #if failMode == 'standalone' :
+        #    LOG.info('add NORMAL')
+        #    s.dpctl('add-flow', 'actions=NORMAL')
+
+        return s
 
     def getAllContainers(self):
         """
@@ -260,6 +299,193 @@
     def CLI(self):
         CLI(self)
 
+    def setLAN(self, vnf_list):
+        """
+        setup an E-LAN network by assigning the same VLAN tag to each DC interface of the VNFs in the E-LAN
+
+        :param vnf_list: names of the VNFs in this E-LAN  [{name:,interface:},...]
+        :return:
+        """
+        src_sw = None
+        src_sw_inport_nr = 0
+        src_sw_inport_name = None
+
+        # get a vlan tag for this E-LAN
+        vlan = self.vlans.pop()
+
+        for vnf in vnf_list:
+            vnf_src_name = vnf['name']
+            vnf_src_interface = vnf['interface']
+
+            # check if port is specified (vnf:port)
+            if vnf_src_interface is None:
+                # take first interface by default
+                connected_sw = self.DCNetwork_graph.neighbors(vnf_src_name)[0]
+                link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+                vnf_src_interface = link_dict[0]['src_port_id']
+
+            for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+                link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+                for link in link_dict:
+                    if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                                link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                        # found the right link and connected switch
+                        src_sw = connected_sw
+                        src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                        src_sw_inport_name = link_dict[link]['dst_port_name']
+                        break
+
+            # set the tag on the dc switch interface
+            LOG.debug('set E-LAN: vnf name: {0} interface: {1} tag: {2}'.format(vnf_src_name, vnf_src_interface,vlan))
+            switch_node = self.getNodeByName(src_sw)
+            self._set_vlan_tag(switch_node, src_sw_inport_name, vlan)
+
+    def _addMonitorFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None,
+                       tag=None, **kwargs):
+        """
+        Add a monitoring flow entry that adds a special flowentry/counter at the begin or end of a chain.
+        So this monitoring flowrule exists on top of a previously defined chain rule and uses the same vlan tag/routing.
+        :param vnf_src_name:
+        :param vnf_dst_name:
+        :param vnf_src_interface:
+        :param vnf_dst_interface:
+        :param tag: vlan tag to be used for this chain (same tag as existing chain)
+        :param monitor_placement: 'tx' or 'rx' indicating to place the extra flowentry resp. at the beginning or end of the chain
+        :return:
+        """
+
+        src_sw = None
+        src_sw_inport_nr = 0
+        src_sw_inport_name = None
+        dst_sw = None
+        dst_sw_outport_nr = 0
+        dst_sw_outport_name = None
+
+        LOG.debug("call AddMonitorFlow vnf_src_name=%r, vnf_src_interface=%r, vnf_dst_name=%r, vnf_dst_interface=%r",
+                  vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface)
+
+        #check if port is specified (vnf:port)
+        if vnf_src_interface is None:
+            # take first interface by default
+            connected_sw = self.DCNetwork_graph.neighbors(vnf_src_name)[0]
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            vnf_src_interface = link_dict[0]['src_port_id']
+
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            for link in link_dict:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    src_sw = connected_sw
+                    src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
+                    break
+
+        if vnf_dst_interface is None:
+            # take first interface by default
+            connected_sw = self.DCNetwork_graph.neighbors(vnf_dst_name)[0]
+            link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
+            vnf_dst_interface = link_dict[0]['dst_port_id']
+
+        vnf_dst_name = vnf_dst_name.split(':')[0]
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_dst_name):
+            link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
+            for link in link_dict:
+                if link_dict[link]['dst_port_id'] == vnf_dst_interface or \
+                        link_dict[link]['dst_port_name'] == vnf_dst_interface:  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    dst_sw = connected_sw
+                    dst_sw_outport_nr = link_dict[link]['src_port_nr']
+                    dst_sw_outport_name = link_dict[link]['src_port_name']
+                    break
+
+        if not tag >= 0:
+            LOG.exception('tag not valid: {0}'.format(tag))
+
+        # get shortest path
+        try:
+            # returns the first found shortest path
+            # if all shortest paths are wanted, use: all_shortest_paths
+            path = nx.shortest_path(self.DCNetwork_graph, src_sw, dst_sw, weight=kwargs.get('weight'))
+        except:
+            LOG.exception("No path could be found between {0} and {1} using src_sw={2} and dst_sw={3}".format(
+                vnf_src_name, vnf_dst_name, src_sw, dst_sw))
+            LOG.debug("Graph nodes: %r" % self.DCNetwork_graph.nodes())
+            LOG.debug("Graph edges: %r" % self.DCNetwork_graph.edges())
+            for e, v in self.DCNetwork_graph.edges():
+                LOG.debug("%r" % self.DCNetwork_graph[e][v])
+            return "No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name)
+
+        LOG.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
+
+        current_hop = src_sw
+        switch_inport_nr = src_sw_inport_nr
+
+        cmd = kwargs.get('cmd')
+
+        #iterate through the path to install the flow-entries
+        for i in range(0,len(path)):
+            current_node = self.getNodeByName(current_hop)
+
+            if path.index(current_hop) < len(path)-1:
+                next_hop = path[path.index(current_hop)+1]
+            else:
+                #last switch reached
+                next_hop = vnf_dst_name
+
+            next_node = self.getNodeByName(next_hop)
+
+            if next_hop == vnf_dst_name:
+                switch_outport_nr = dst_sw_outport_nr
+                LOG.info("end node reached: {0}".format(vnf_dst_name))
+            elif not isinstance( next_node, OVSSwitch ):
+                LOG.info("Next node: {0} is not a switch".format(next_hop))
+                return "Next node: {0} is not a switch".format(next_hop)
+            else:
+                # take first link between switches by default
+                index_edge_out = 0
+                switch_outport_nr = self.DCNetwork_graph[current_hop][next_hop][index_edge_out]['src_port_nr']
+
+
+           # set of entry via ovs-ofctl
+            if isinstance( current_node, OVSSwitch ):
+                kwargs['vlan'] = tag
+                kwargs['path'] = path
+                kwargs['current_hop'] = current_hop
+                kwargs['switch_inport_name'] = src_sw_inport_name
+                kwargs['switch_outport_name'] = dst_sw_outport_name
+                kwargs['skip_vlan_tag'] = True
+
+                monitor_placement = kwargs.get('monitor_placement').strip()
+                # put monitor flow at the dst switch
+                insert_flow = False
+                if monitor_placement == 'tx' and path.index(current_hop) == 0:  # first node:
+                    insert_flow = True
+                # put monitoring flow at the src switch
+                elif monitor_placement == 'rx' and path.index(current_hop) == len(path) - 1:  # last node:
+                    insert_flow = True
+                elif monitor_placement not in ['rx', 'tx']:
+                    LOG.exception('invalid monitor command: {0}'.format(monitor_placement))
+
+
+                if self.controller == RemoteController and insert_flow:
+                    ## set flow entry via ryu rest api
+                    self._set_flow_entry_ryu_rest(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
+                    break
+                elif insert_flow:
+                    ## set flow entry via ovs-ofctl
+                    self._set_flow_entry_dpctl(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
+                    break
+
+            # take first link between switches by default
+            if isinstance( next_node, OVSSwitch ):
+                switch_inport_nr = self.DCNetwork_graph[current_hop][next_hop][0]['dst_port_nr']
+                current_hop = next_hop
+
+        return "path {2} between {0} and {1}".format(vnf_src_name, vnf_dst_name, cmd)
+
+
     def setChain(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
         """
         Chain 2 vnf interfaces together by installing the flowrules in the switches along their path.
@@ -274,24 +500,47 @@
         :param cookie: cookie for the installed flowrules (can be used later as identifier for a set of installed chains)
         :param match: custom match entry to be added to the flowrules (default: only in_port and vlan tag)
         :param priority: custom flowrule priority
+<<<<<<< HEAD
+        :param monitor: boolean to indicate whether this chain is a monitoring chain
+        :param tag: vlan tag to be used for this chain (pre-defined or new one if none is specified)
+=======
         :param path: custom path between the two VNFs (list of switches)
+>>>>>>> upstream/master
         :return: output log string
         """
+
+        # special procedure for monitoring flows
+        if kwargs.get('monitor'):
+
+            # check if chain already exists
+            found_chains = [chain_dict for chain_dict in self.installed_chains if
+             (chain_dict['vnf_src_name'] == vnf_src_name and chain_dict['vnf_src_interface'] == vnf_src_interface
+             and chain_dict['vnf_dst_name'] == vnf_dst_name and chain_dict['vnf_dst_interface'] == vnf_dst_interface)]
+
+            if len(found_chains) > 0:
+                # this chain exists, so need an extra monitoring flow
+                # assume only 1 chain per vnf/interface pair
+                LOG.debug('*** installing monitoring chain on top of pre-defined chain from {0}:{1} -> {2}:{3}'.
+                            format(vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface))
+                tag = found_chains[0]['tag']
+                ret = self._addMonitorFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface,
+                                     tag=tag, table_id=0, **kwargs)
+                return ret
+            else:
+                # no chain existing (or E-LAN) -> install normal chain
+                LOG.warning('*** installing monitoring chain without pre-defined NSD chain from {0}:{1} -> {2}:{3}'.
+                            format(vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface))
+                pass
+
+
         cmd = kwargs.get('cmd')
-        if cmd == 'add-flow':
+        if cmd == 'add-flow' or cmd == 'del-flows':
             ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
             if kwargs.get('bidirectional'):
                 if kwargs.get('path') is not None:
                     kwargs['path'] = list(reversed(kwargs.get('path')))
                 ret = ret +'\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
 
-        elif cmd == 'del-flows':
-            ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
-            if kwargs.get('bidirectional'):
-                if kwargs.get('path') is not None:
-                    kwargs['path'] = list(reversed(kwargs.get('path')))
-                ret = ret + '\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
-
         else:
             ret = "Command unknown"
 
@@ -301,9 +550,11 @@
     def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
 
         src_sw = None
-        dst_sw = None
         src_sw_inport_nr = 0
+        src_sw_inport_name = None
+        dst_sw = None
         dst_sw_outport_nr = 0
+        dst_sw_outport_name = None
 
         LOG.debug("call chainAddFlow vnf_src_name=%r, vnf_src_interface=%r, vnf_dst_name=%r, vnf_dst_interface=%r",
                   vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface)
@@ -323,6 +574,7 @@
                     # found the right link and connected switch
                     src_sw = connected_sw
                     src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
                     break
 
         if vnf_dst_interface is None:
@@ -340,6 +592,7 @@
                     # found the right link and connected switch
                     dst_sw = connected_sw
                     dst_sw_outport_nr = link_dict[link]['src_port_nr']
+                    dst_sw_outport_name = link_dict[link]['src_port_name']
                     break
 
         path = kwargs.get('path')
@@ -363,13 +616,28 @@
         current_hop = src_sw
         switch_inport_nr = src_sw_inport_nr
 
-        # choose free vlan if path contains more than 1 switch
+        # choose free vlan
+        ## if path contains more than 1 switch
         cmd = kwargs.get('cmd')
         vlan = None
         if cmd == 'add-flow':
-            if len(path) > 1:
+            if kwargs.get('tag'):
+                # use pre-defined tag
+                vlan = kwargs.get('tag')
+            else:
                 vlan = self.vlans.pop()
 
+        # store the used vlan tag to identify this chain
+        if not kwargs.get('monitor'):
+            chain_dict = {}
+            chain_dict['vnf_src_name'] = vnf_src_name
+            chain_dict['vnf_dst_name'] = vnf_dst_name
+            chain_dict['vnf_src_interface'] = vnf_src_interface
+            chain_dict['vnf_dst_interface'] = vnf_dst_interface
+            chain_dict['tag'] = vlan
+            self.installed_chains.append(chain_dict)
+
+        #iterate through the path to install the flow-entries
         for i in range(0,len(path)):
             current_node = self.getNodeByName(current_hop)
 
@@ -397,6 +665,9 @@
             if isinstance( current_node, OVSSwitch ):
                 kwargs['vlan'] = vlan
                 kwargs['path'] = path
+                kwargs['current_hop'] = current_hop
+                kwargs['switch_inport_name'] = src_sw_inport_name
+                kwargs['switch_outport_name'] = dst_sw_outport_name
                 kwargs['pathindex'] = i
 
                 if self.controller == RemoteController:
@@ -406,8 +677,6 @@
                     ## set flow entry via ovs-ofctl
                     self._set_flow_entry_dpctl(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
 
-
-
             # take first link between switches by default
             if isinstance( next_node, OVSSwitch ):
                 switch_inport_nr = self.DCNetwork_graph[current_hop][next_hop][0]['dst_port_nr']
@@ -426,6 +695,12 @@
 
         vlan = kwargs.get('vlan')
         priority = kwargs.get('priority')
+        # flag to not set the ovs port vlan tag
+        skip_vlan_tag = kwargs.get('skip_vlan_tag')
+        # table id to put this flowentry
+        table_id = kwargs.get('table_id')
+        if not table_id:
+            table_id = 0
 
         s = ','
         if match_input:
@@ -439,6 +714,8 @@
         if priority:
             flow['priority'] = int(priority)
 
+        flow['table_id'] = table_id
+
         flow['actions'] = []
 
         # possible Ryu actions, match fields:
@@ -447,23 +724,38 @@
             prefix = 'stats/flowentry/add'
             if vlan != None:
                 if index == 0:  # first node
-                    action = {}
-                    action['type'] = 'PUSH_VLAN'  # Push a new VLAN tag if a input frame is non-VLAN-tagged
-                    action['ethertype'] = 33024   # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
-                    flow['actions'].append(action)
-                    action = {}
-                    action['type'] = 'SET_FIELD'
-                    action['field'] = 'vlan_vid'
-                    # ryu expects the field to be masked
-                    action['value'] = vlan | 0x1000
-                    flow['actions'].append(action)
-                elif index == len(path) -1:  # last node
-                    match += ',dl_vlan=%s' % vlan
-                    action = {}
-                    action['type'] = 'POP_VLAN'
-                    flow['actions'].append(action)
+                    # set vlan tag in ovs instance (to isolate E-LANs)
+                    if not skip_vlan_tag:
+                        in_port_name = kwargs.get('switch_inport_name')
+                        self._set_vlan_tag(node, in_port_name, vlan)
+                    # set vlan push action if more than 1 switch in the path
+                    if len(path) > 1:
+                        action = {}
+                        action['type'] = 'PUSH_VLAN'  # Push a new VLAN tag if a input frame is non-VLAN-tagged
+                        action['ethertype'] = 33024   # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
+                        flow['actions'].append(action)
+                        action = {}
+                        action['type'] = 'SET_FIELD'
+                        action['field'] = 'vlan_vid'
+                        # ryu expects the field to be masked
+                        action['value'] = vlan | 0x1000
+                        flow['actions'].append(action)
+
+                elif index == len(path) - 1:  # last node
+                    # set vlan tag in ovs instance (to isolate E-LANs)
+                    if not skip_vlan_tag:
+                        out_port_name = kwargs.get('switch_outport_name')
+                        self._set_vlan_tag(node, out_port_name, vlan)
+                    # set vlan pop action if more than 1 switch in the path
+                    if len(path) > 1:
+                        match += ',dl_vlan=%s' % vlan
+                        action = {}
+                        action['type'] = 'POP_VLAN'
+                        flow['actions'].append(action)
+
                 else:  # middle nodes
                     match += ',dl_vlan=%s' % vlan
+
             # output action must come last
             action = {}
             action['type'] = 'OUTPUT'
@@ -485,7 +777,12 @@
         flow['match'] = self._parse_match(match)
         self.ryu_REST(prefix, data=flow)
 
+    def _set_vlan_tag(self, node, switch_port, tag):
+        node.vsctl('set', 'port {0} tag={1}'.format(switch_port,tag))
+        LOG.debug("set vlan in switch: {0} in_port: {1} vlan tag: {2}".format(node.name, switch_port, tag))
+
     def _set_flow_entry_dpctl(self, node, switch_inport_nr, switch_outport_nr, **kwargs):
+
         match = 'in_port=%s' % switch_inport_nr
 
         cookie = kwargs.get('cookie')
@@ -526,7 +823,11 @@
     def startRyu(self, learning_switch=True):
         # start Ryu controller with rest-API
         python_install_path = site.getsitepackages()[0]
-        ryu_path = python_install_path + '/ryu/app/simple_switch_13.py'
+        # ryu default learning switch
+        #ryu_path = python_install_path + '/ryu/app/simple_switch_13.py'
+        #custom learning switch that installs a default NORMAL action in the ovs switches
+        dir_path = os.path.dirname(os.path.realpath(__file__))
+        ryu_path = dir_path + '/son_emu_simple_switch_13.py'
         ryu_path2 = python_install_path + '/ryu/app/ofctl_rest.py'
         # change the default Openflow controller port to 6653 (official IANA-assigned port number), as used by Mininet
         # Ryu still uses 6633 as default
@@ -536,9 +837,12 @@
         FNULL = open("/tmp/ryu.log", 'w')
         if learning_switch:
             self.ryu_process = Popen([ryu_cmd, ryu_path, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path))
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path2))
         else:
             # no learning switch, but with rest api
             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path2))
         time.sleep(1)
 
     def killRyu(self):
@@ -600,3 +904,14 @@
                 dict.update({match[0]:m2})
         return dict
 
+    def find_connected_dc_interface(self, vnf_src_name, vnf_src_interface):
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            for link in link_dict:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    src_sw = connected_sw
+                    src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
+                    return src_sw_inport_name
diff --git a/src/emuvim/dcemulator/node.py b/src/emuvim/dcemulator/node.py
index a0112cf..2702bf5 100755
--- a/src/emuvim/dcemulator/node.py
+++ b/src/emuvim/dcemulator/node.py
@@ -38,7 +38,6 @@
 
 DCDPID_BASE = 1000  # start of switch dpid's used for data center switches
 
-
 class EmulatorCompute(Docker):
     """
     Emulator specific compute node class.
@@ -61,9 +60,17 @@
         Helper method to receive information about the virtual networks
         this compute instance is connected to.
         """
-        # format list of tuples (name, Ip, MAC, isUp, status)
-        return [{'intf_name':str(i), 'ip':i.IP(), 'mac':i.MAC(), 'up':i.isUp(), 'status':i.status()}
-                for i in self.intfList()]
+        # get all links and find dc switch interface
+        networkStatusList = []
+        for i in self.intfList():
+            vnf_name = self.name
+            vnf_interface = str(i)
+            dc_port_name = self.datacenter.net.find_connected_dc_interface(vnf_name, vnf_interface)
+            # format list of tuples (name, Ip, MAC, isUp, status, dc_portname)
+            intf_dict = {'intf_name': str(i), 'ip': i.IP(), 'mac': i.MAC(), 'up': i.isUp(), 'status': i.status(), 'dc_portname': dc_port_name}
+            networkStatusList.append(intf_dict)
+
+        return networkStatusList
 
     def getStatus(self):
         """
@@ -83,6 +90,7 @@
         status["memswap_limit"] = self.memswap_limit
         status["state"] = self.dcli.inspect_container(self.dc)["State"]
         status["id"] = self.dcli.inspect_container(self.dc)["Id"]
+        status["short_id"] = self.dcli.inspect_container(self.dc)["Id"][:12]
         status["datacenter"] = (None if self.datacenter is None
                                 else self.datacenter.label)
         return status
@@ -166,6 +174,12 @@
             if len(network) < 1:
                 network.append({})
 
+        # apply hard-set resource limits=0
+        cpu_percentage = params.get('cpu_percent')
+        if cpu_percentage:
+            params['cpu_period'] = self.net.cpu_period
+            params['cpu_quota'] = self.net.cpu_period * float(cpu_percentage)
+
         # create the container
         d = self.net.addDocker(
             "%s" % (name),
@@ -173,9 +187,12 @@
             dcmd=command,
             datacenter=self,
             flavor_name=flavor_name,
+            environment = {'VNF_NAME':name},
             **params
         )
 
+
+
         # apply resource limits to container if a resource model is defined
         if self._resource_model is not None:
             try:
diff --git a/src/emuvim/dcemulator/son_emu_simple_switch_13.py b/src/emuvim/dcemulator/son_emu_simple_switch_13.py
new file mode 100755
index 0000000..53d1a2e
--- /dev/null
+++ b/src/emuvim/dcemulator/son_emu_simple_switch_13.py
@@ -0,0 +1,134 @@
+# Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
+#
+# 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.
+
+from ryu.base import app_manager
+from ryu.controller import ofp_event
+from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
+from ryu.controller.handler import set_ev_cls
+from ryu.ofproto import ofproto_v1_3
+from ryu.lib.packet import packet
+from ryu.lib.packet import ethernet
+from ryu.lib.packet import ether_types
+from ryu.topology.event import EventSwitchEnter, EventSwitchLeave, EventSwitchReconnected
+
+class SimpleSwitch13(app_manager.RyuApp):
+    OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
+
+    def __init__(self, *args, **kwargs):
+        super(SimpleSwitch13, self).__init__(*args, **kwargs)
+        self.mac_to_port = {}
+
+    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
+    def switch_features_handler(self, ev):
+        datapath = ev.msg.datapath
+        ofproto = datapath.ofproto
+        parser = datapath.ofproto_parser
+
+        # install table-miss flow entry
+        #
+        # We specify NO BUFFER to max_len of the output action due to
+        # OVS bug. At this moment, if we specify a lesser number, e.g.,
+        # 128, OVS will send Packet-In with invalid buffer_id and
+        # truncated packet data. In that case, we cannot output packets
+        # correctly.  The bug has been fixed in OVS v2.1.0.
+        match = parser.OFPMatch()
+        #actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
+        #                                  ofproto.OFPCML_NO_BUFFER)]
+        actions = [parser.OFPActionOutput(ofproto.OFPCML_NO_BUFFER)]
+        self.add_flow(datapath, 0, match, actions)
+
+    def add_flow(self, datapath, priority, match, actions, buffer_id=None, table_id=0):
+        ofproto = datapath.ofproto
+        parser = datapath.ofproto_parser
+
+        inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,
+                                             actions)]
+        if buffer_id:
+            mod = parser.OFPFlowMod(datapath=datapath, buffer_id=buffer_id,
+                                    priority=priority, match=match,
+                                    instructions=inst, table_id=table_id)
+        else:
+            mod = parser.OFPFlowMod(datapath=datapath, priority=priority,
+                                    match=match, instructions=inst, table_id=table_id)
+        datapath.send_msg(mod)
+
+        # new switch detected
+
+    @set_ev_cls([EventSwitchEnter, EventSwitchReconnected])
+    def _ev_switch_enter_handler(self, ev):
+        datapath = ev.switch.dp
+        self.logger.info('registered OF switch id: %s' % datapath.id)
+        ofproto = datapath.ofproto
+        self.logger.info('OF version: {0}'.format(ofproto))
+        # send NORMAL action for all undefined flows
+        ofp_parser = datapath.ofproto_parser
+        actions = [ofp_parser.OFPActionOutput(ofproto_v1_3.OFPP_NORMAL)]
+        self.add_flow(datapath, 0, None, actions, table_id=0)
+
+
+    @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
+    def _packet_in_handler(self, ev):
+        # If you hit this you might want to increase
+        # the "miss_send_length" of your switch
+        if ev.msg.msg_len < ev.msg.total_len:
+            self.logger.debug("packet truncated: only %s of %s bytes",
+                              ev.msg.msg_len, ev.msg.total_len)
+        msg = ev.msg
+        datapath = msg.datapath
+        ofproto = datapath.ofproto
+        parser = datapath.ofproto_parser
+        in_port = msg.match['in_port']
+
+        pkt = packet.Packet(msg.data)
+        eth = pkt.get_protocols(ethernet.ethernet)[0]
+
+        if eth.ethertype == ether_types.ETH_TYPE_LLDP:
+            # ignore lldp packet
+            return
+        dst = eth.dst
+        src = eth.src
+
+        dpid = datapath.id
+        self.mac_to_port.setdefault(dpid, {})
+
+        self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)
+
+        # learn a mac address to avoid FLOOD next time.
+        self.mac_to_port[dpid][src] = in_port
+
+        if dst in self.mac_to_port[dpid]:
+            out_port = self.mac_to_port[dpid][dst]
+        else:
+            out_port = ofproto.OFPP_FLOOD
+
+        actions = [parser.OFPActionOutput(out_port)]
+
+        # install a flow to avoid packet_in next time
+        if out_port != ofproto.OFPP_FLOOD:
+            match = parser.OFPMatch(in_port=in_port, eth_dst=dst)
+            # verify if we have a valid buffer_id, if yes avoid to send both
+            # flow_mod & packet_out
+            if msg.buffer_id != ofproto.OFP_NO_BUFFER:
+                self.add_flow(datapath, 1, match, actions, msg.buffer_id)
+                return
+            else:
+                self.add_flow(datapath, 1, match, actions)
+        data = None
+        if msg.buffer_id == ofproto.OFP_NO_BUFFER:
+            data = msg.data
+
+        out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id,
+                                  in_port=in_port, actions=actions, data=data)
+        datapath.send_msg(out)
diff --git a/src/emuvim/examples/sonata_simple.py b/src/emuvim/examples/sonata_simple.py
new file mode 100755
index 0000000..0627247
--- /dev/null
+++ b/src/emuvim/examples/sonata_simple.py
@@ -0,0 +1,78 @@
+"""
+Copyright (c) 2015 SONATA-NFV
+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.
+
+Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
+nor the names of its contributors may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+This work has been performed in the framework of the SONATA project,
+funded by the European Commission under Grant number 671517 through
+the Horizon 2020 and 5G-PPP programmes. The authors would like to
+acknowledge the contributions of their colleagues of the SONATA
+partner consortium (www.sonata-nfv.eu).
+"""
+"""
+A simple topology with two PoPs for the y1 demo story board.
+
+        (dc1) <<-->> s1 <<-->> (dc2)
+
+- SAP deployment enabled
+- learning switch enabled
+"""
+
+import logging
+from mininet.log import setLogLevel
+from emuvim.dcemulator.net import DCNetwork
+from emuvim.api.rest.rest_api_endpoint import RestApiEndpoint
+from emuvim.api.sonata import SonataDummyGatekeeperEndpoint
+from mininet.node import RemoteController
+
+logging.basicConfig(level=logging.INFO)
+
+
+def create_topology1():
+    # create topology
+    net = DCNetwork(controller=RemoteController, monitor=True, enable_learning=True)
+    dc1 = net.addDatacenter("dc1")
+
+
+    # add the command line interface endpoint to each DC (REST API)
+    rapi1 = RestApiEndpoint("0.0.0.0", 5001)
+    rapi1.connectDCNetwork(net)
+    rapi1.connectDatacenter(dc1)
+    # run API endpoint server (in another thread, don't block)
+    rapi1.start()
+
+    # add the SONATA dummy gatekeeper to each DC
+    sdkg1 = SonataDummyGatekeeperEndpoint("0.0.0.0", 5000, deploy_sap=True)
+    sdkg1.connectDatacenter(dc1)
+    # run the dummy gatekeeper (in another thread, don't block)
+    sdkg1.start()
+
+    # start the emulation platform
+    net.start()
+    net.CLI()
+    net.stop()
+
+
+def main():
+    setLogLevel('info')  # set Mininet loglevel
+    create_topology1()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/src/emuvim/examples/sonata_simple_topology.py b/src/emuvim/examples/sonata_simple_topology.py
new file mode 100755
index 0000000..0627247
--- /dev/null
+++ b/src/emuvim/examples/sonata_simple_topology.py
@@ -0,0 +1,78 @@
+"""
+Copyright (c) 2015 SONATA-NFV
+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.
+
+Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
+nor the names of its contributors may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+This work has been performed in the framework of the SONATA project,
+funded by the European Commission under Grant number 671517 through
+the Horizon 2020 and 5G-PPP programmes. The authors would like to
+acknowledge the contributions of their colleagues of the SONATA
+partner consortium (www.sonata-nfv.eu).
+"""
+"""
+A simple topology with two PoPs for the y1 demo story board.
+
+        (dc1) <<-->> s1 <<-->> (dc2)
+
+- SAP deployment enabled
+- learning switch enabled
+"""
+
+import logging
+from mininet.log import setLogLevel
+from emuvim.dcemulator.net import DCNetwork
+from emuvim.api.rest.rest_api_endpoint import RestApiEndpoint
+from emuvim.api.sonata import SonataDummyGatekeeperEndpoint
+from mininet.node import RemoteController
+
+logging.basicConfig(level=logging.INFO)
+
+
+def create_topology1():
+    # create topology
+    net = DCNetwork(controller=RemoteController, monitor=True, enable_learning=True)
+    dc1 = net.addDatacenter("dc1")
+
+
+    # add the command line interface endpoint to each DC (REST API)
+    rapi1 = RestApiEndpoint("0.0.0.0", 5001)
+    rapi1.connectDCNetwork(net)
+    rapi1.connectDatacenter(dc1)
+    # run API endpoint server (in another thread, don't block)
+    rapi1.start()
+
+    # add the SONATA dummy gatekeeper to each DC
+    sdkg1 = SonataDummyGatekeeperEndpoint("0.0.0.0", 5000, deploy_sap=True)
+    sdkg1.connectDatacenter(dc1)
+    # run the dummy gatekeeper (in another thread, don't block)
+    sdkg1.start()
+
+    # start the emulation platform
+    net.start()
+    net.CLI()
+    net.stop()
+
+
+def main():
+    setLogLevel('info')  # set Mininet loglevel
+    create_topology1()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_mon_and_sap.py b/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_mon_and_sap.py
old mode 100644
new mode 100755
index df7a6ac..b38720e
--- a/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_mon_and_sap.py
+++ b/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_mon_and_sap.py
@@ -46,7 +46,7 @@
 
 def create_topology1():
     # create topology
-    net = DCNetwork(controller=RemoteController, monitor=True, enable_learning=False)
+    net = DCNetwork(controller=RemoteController, monitor=True, enable_learning=True)
     dc1 = net.addDatacenter("dc1")
     dc2 = net.addDatacenter("dc2")
     s1 = net.addSwitch("s1")
diff --git a/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_sap.py b/src/emuvim/examples/sonata_y1_demo_topology_1_w_ls_and_sap.py
old mode 100644
new mode 100755
diff --git a/src/emuvim/test/api_base.py b/src/emuvim/test/api_base.py
index 614ecd2..57d4aa5 100755
--- a/src/emuvim/test/api_base.py
+++ b/src/emuvim/test/api_base.py
@@ -108,7 +108,7 @@
         Helper to interact with local docker instance.
         """
         if self.docker_cli is None:
-            self.docker_cli = docker.Client(
+            self.docker_cli = docker.APIClient(
                 base_url='unix://var/run/docker.sock')
         return self.docker_cli
 
diff --git a/src/emuvim/test/base.py b/src/emuvim/test/base.py
index 1b06f25..397e2a1 100755
--- a/src/emuvim/test/base.py
+++ b/src/emuvim/test/base.py
@@ -100,7 +100,7 @@
         Helper to interact with local docker instance.
         """
         if self.docker_cli is None:
-            self.docker_cli = docker.Client(
+            self.docker_cli = docker.APIClient(
                 base_url='unix://var/run/docker.sock')
         return self.docker_cli
 
diff --git a/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py b/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
index c96e1ba..bfa9541 100755
--- a/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
+++ b/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
@@ -44,7 +44,7 @@
 #    @unittest.skip("disabled")
     def test_GK_Api_start_service(self):
         # create network
-        self.createNet(nswitches=0, ndatacenter=2, nhosts=2, ndockers=0)
+        self.createNet(nswitches=0, ndatacenter=2, nhosts=2, ndockers=0, enable_learning=True)
         # setup links
         self.net.addLink(self.dc[0], self.h[0])
         self.net.addLink(self.dc[0], self.dc[1])
@@ -87,9 +87,37 @@
         # check compute list result
         self.assertEqual(len(self.dc[0].listCompute()), 2)
         # check connectivity by using ping
+        ELAN_list=[]
+        for i in [0]:
+            for vnf in self.dc[i].listCompute():
+                # check connection
+                p = self.net.ping([self.h[i], vnf])
+                print p
+                self.assertTrue(p <= 0.0)
+
+                # check E LAN connection
+                network_list = vnf.getNetworkStatus()
+                mgmt_ip = [intf['ip'] for intf in network_list if intf['intf_name'] == 'mgmt']
+                self.assertTrue(len(mgmt_ip) > 0)
+                ip_address = mgmt_ip[0]
+                ELAN_list.append(ip_address)
+                print ip_address
+
+        # check ELAN connection by ping over the mgmt network (needs to be configured as ELAN in the test service)
         for vnf in self.dc[0].listCompute():
-            p = self.net.ping([self.h[0], vnf])
-            self.assertTrue(p <= 50.0)
+            network_list = vnf.getNetworkStatus()
+            mgmt_ip = [intf['ip'] for intf in network_list if intf['intf_name'] == 'mgmt']
+            self.assertTrue(len(mgmt_ip) > 0)
+            ip_address = mgmt_ip[0]
+            print ELAN_list
+            print ip_address
+            test_ip_list = list(ELAN_list)
+            test_ip_list.remove(ip_address)
+            for ip in test_ip_list:
+                p = self.net.ping([vnf],manualdestip=ip)
+                print p
+                self.assertTrue(p <= 0.0)
+
         # stop Mininet network
         self.stopNet()
         initialize_GK()