Reference: http://www.alfawzan.af.org.sa/node/16884
Question: Who are those from my relatives with whom it is obligatory upon me to maintain ties of kinship?
Response: Everyone to whom you are related [both] from your father’s and mother’s side; such as the grandparents, and paternal uncles and aunties, and maternal uncles and aunties. So they are your relatives with whom you should maintain ties of kinship according to your ability – whether that be by visiting them, or extending the greeting of as-salaam [‘alaykum] to them; and particularly those who are closest [in relation to you].
