A Confusing Problem

One fine day, John's telephone rang, so he picked up the telephone and asked who was calling. The reply was, "I am your father's mother's brother's daughter's sister's son." In reality, the caller was John's brother, and they had a nice chat through the telephone. After an hour, the telephone rang again. John picked up the telephone and again asked who was calling. The reply was, "I am your aunt's father's brother-in-law's son's wife's mother." So was the caller from John's father's mother or John's mother's mother?