def startTopology(self, topologyObjList='all'):
        """
        Description
            Start a Topology Group and all of its protocol stacks.

        Parameters
            topologyObjList: <str>|<list>: 'all' or a list of Topology Group href.
                             Ex: ['/api/v1/sessions/1/ixnetwork/topology/1']
        """
        if topologyObjList == 'all':
            queryData = {'from': '/',
                         'nodes': [{'node': 'topology', 'properties': ['href'], 'where': []}]
                        }

           # QUERY FOR THE BGP HOST ATTRIBITE OBJECTS
            queryResponse = self.ixnObj.query(data=queryData)
            try:
                topologyList = queryResponse.json()['result'][0]['topology']
            except IndexError:
                raise IxNetRestApiException('\nNo Topology Group objects  found')

            topologyObjList = [topology['href'] for topology in topologyList]

        url = self.ixnObj.sessionUrl+'/topology/operations/start'
        response = self.ixnObj.post(url, data={'arg1': topologyObjList})
        self.ixnObj.waitForComplete(response, url+'/'+response.json()['id'])
        self.verifyDeviceGroupStatus()