LocalTalk link access protocol (Apple) (LLAP)
The LLAP protocol is a link layerApple protocol that manages transmission between nodes in a LocalTalk network.
LocalTalk Link Access Protocol (LLAP) manages access to the bus, uses Carrier Sense Multiple Access with Collision Avoidance( CSMA/ CA) as the access method, provides an addressing scheme for the node, controls data transmission and its reception, and ensures proper packet length.
The LLAP data frame consists of a 2- byte flag, the Identification Number( ID) for the destination and source nodes, Destination Node ID and Source Node ID, the LLAP Type field, the data length and data, and the checksum field( FCS). The payload preceding the checksum field can contain up to 600 bytes ofpayload data. The flags at the beginning and at the end of the data fields form the limitation.