def network_manager():
    '''
    Deals with the renaming of Quantum to Neutron in H and any situations
    that require compatability (eg, deploying H with network-manager=quantum,
    upgrading from G).
    '''
    release = os_release('nova-common')
    manager = config('network-manager').lower()

    if manager not in ['quantum', 'neutron']:
        return manager

    if release in ['essex']:
        # E does not support neutron
        log('Neutron networking not supported in Essex.', level=ERROR)
        raise Exception
    elif release in ['folsom', 'grizzly']:
        # neutron is named quantum in F and G
        return 'quantum'
    else:
        # ensure accurate naming for all releases post-H
        return 'neutron'
Deals with the renaming of Quantum to Neutron in H and any situations
    that require compatability (eg, deploying H with network-manager=quantum,
    upgrading from G).