The latter scheme, in which the hosts use a single virtual circuit for multiple protocols, is referred to in RFC 2684 as "LLC Encapsulation". The standards suggest that hosts should use a standard IEEE 802.2 "Logical Link Control" (LLC) header, followed by a "Subnetwork Access Protocol" (SNAP) header if necessary. This scheme has the advantage of allowing all traffic over the same circuit, but the disadvantage of requiring each packet to contain octets that identify the protocol type, which adds overhead. The scheme also has the disadvantage that packets from all protocols travel with the same delay and priority.