def full_callsign(callsign):
    """
    Returns a fully-formatted callsign (Callsign + SSID).

    :param callsign: Callsign Dictionary {'callsign': '', 'ssid': n}
    :type callsign: dict
    :returns: Callsign[-SSID].
    :rtype: str
    """
    if callsign['ssid'] > 0:
        return '-'.join([callsign['callsign'], str(callsign['ssid'])])
    else:
        return callsign['callsign']