def modifyTopologyPortsNgpf(self, topologyObj, portList, topologyName=None):
        """
        Description
           Add/remove Topology ports.

        Parameters
           topologyObj: <str>: The Topology Group object.
           portList: <list>: A list of all the ports that you want for the Topology even if the port exists in
                             the Topology.

           topologyName: <st>: The Topology Group name to modify.
           
        Requirements:
            1> You must have already connected all the required ports for your configuration. Otherwise,
               adding additional port(s) that doesn't exists in your configuration's assigned port list
               will not work.

            2> This API requires getVports()

        Examples
           topologyObj = '/api/v1/sessions/1/ixnetwork/topology/1'

           portList format = [(str(chassisIp), str(slotNumber), str(portNumber))]
               Example 1: [ ['192.168.70.10', '1', '1'] ]
               Example 2: [ ['192.168.70.10', '1', '1'], ['192.168.70.10', '2', '1'] ]
        """
        vportList = self.portMgmtObj.getVports(portList)
        if len(vportList) != len(portList):
            raise IxNetRestApiException('modifyTopologyPortsNgpf: There is not enough vports created to match the number of ports.')
        self.ixnObj.logInfo('vportList: %s' % vportList)
        topologyData = {'vports': vportList}
        response = self.ixnObj.patch(self.ixnObj.httpHeader+topologyObj, data=topologyData)