My Optus over the head cable connection is going to be replaced with NBN. Any chance NBN FTTC will be able to give me under ground connection ?
Have you checked the NBN address checker to confirm you are getting FTTC? If you are then this technology uses your existing phone line so yes it will be under ground. Your Optus cable will be removed eventually. Note households with FTTC are changing a lot at the moment so it may still be a while until you can be sure if you're getting FTTC.