Return all distribution names known by an index.
    :param url: The URL of the index.
    :return: A list of all known distribution names.

def get_all_distribution_names(url=None):
    """
    Return all distribution names known by an index.
    :param url: The URL of the index.
    :return: A list of all known distribution names.
    """
    if url is None:
        url = DEFAULT_INDEX
    client = ServerProxy(url, timeout=3.0)
    return client.list_packages()