subnetwork access protocol (IP) (SNAP)
The Subnetwork Access Protocol(SNAP) is a link layerIP protocol that belongs to IEEE 802.2 Logical Link Control( LLC). SNAP operates between the network instances(entities) of a subnet and a network instance in the end system.
The SNAP protocol specifies a standard method for encapsulating IP datagrams and Address Resolution Protocol ( ARP) messages on IEEE networks.
The SNAP instance in the end system uses the services of the subnet and provides data transfer, connection management, and quality of service selection as functions. The MAC data frame of SNAP differs from the 802.3 data frame by the five byte Protocol Identifier( PI) data field, which is used to identify routed protocols.