Which of the following digits are known as the sub-address digits of the Network User Address?
8-12 digits are known as the sub-address digits of the Network User Address.
GTIN-12 (UPC-A): this is a 12-digit number used primarily in North America. GTIN-8 (EAN/UCC-8): this is an 8-digit number used predominately outside of North America. The X.25 DTE
Address is often referred to as the Network User Address (NUA), although strictly speaking the NUA is the base address allocated by a network to a subscriber, not including the sub-address. The format of addresses for public networks is specified in X.121.