def getPortObjectId(connection, sessionUrl, communityPortIdTuple):
    '''
        This method is used to get the objectID of a port from a communityList.

        Args:
        - connection is the connection object that manages the HTTP data transfers between the client and the REST API
        - communityPortIdTuple is a tuple composed of (communityID and portName)
            - communityID is the id of the community list for which captures should be retrieved.
            - portName is the name of the port for which the objectID will be retrieved ( in the following format:'1.5.1')
        - sessionUrl is the address of the session on which the test was ran.
    '''
    communityObjectID, portID = communityPortIdTuple
    communityUrl = sessionUrl + ("/ixload/test/activeTest/communityList/%s/network/portList" % communityObjectID)
    portList = connection.httpRequest('GET', communityUrl).json()

    objectID = None
    for port in portList:
        if port['id'] == portID:
            objectID = port["objectID"]
            break

    if objectID is None:
        raise Exception("Could not find port with id '%s' on community with id '%s'" % (portID, communityObjectID))

    return objectID