A system for communicating protocol layer processing information is disclosed herein. A transmitter includes a protocol layer header generator that generators a header for a first protocol data unit. The header generator provides a first header comprising a first sequence number field that determines the order in which a receiving entity present the first data unit to higher protocol layer. The sequence number field varies in length. A receiver includes a protocol layer header parser that parses a header of a first protocol data unit. The header parser parses a first header comprising a first sequence number field that determines the order in which the first data unit is presented to a higher protocol layer. The sequence number field varies in length.
