SIMPLE DATA LINK (SDL) PROTOCOL

摘要

A simple point-to-point data link protocol (SDL) is defined which is based onthe use ofa length indicator field and an error check field, rather than a flag, forperforming packetboundary recovery in a receiver. In an embodiment of the invention, an SDLtransmittertransmits SDL packets comprising a header and a variable length payload. TheSDLheader comprises a length indicator (LI) field, a type field and a cyclicredundancy check(CRC) field. For receiving these transmitted SDL packets, SDL supports the useof aself-synchronization/self-delineation technique in the receiver. The receiverperformsself-delineation as a function of the LI field, and performs selfsynchronization, or packetrecovery, as a function of both the LI field and the header CRC field. Inparticular, inperforming packet recovery, the receiver performs a CRC check over eachreceived SDLpacket header and synchronization is declared after N correct checks, e.g., N= 4. TheSDL receiver operates in a hunt made when performing synchronization, and anormalmode when synchronization has been accomplished.