sentences:  RFC 2684 specifies that hosts can choose between the two methods of using AAL5.Both the sender and receiver must agree on how the circuit will be used, and the agreement may involve manual configuration.Furthermore, the standards suggest that when hosts choose to include type information in the packet, they should use a standard IEEE 802.2 "Logical Link Control" (LLC) header, followed by a "Subnetwork Access Protocol" (SNAP) header if necessary.