Specifies multilink procedures where a multiplicity of parallel data links at the data link layer are used to provide a variable bandwidth data link between network layer entities. The multilink procedures (MLP) exist as a new upper sublayer of the data link layer, operating between the network layer and a multiplicity of single data link protocol functions (SLPs) in the data link layer. This Standard does not specify the way in which the SLPs indicate to the MLP that the transmission of a multilink frame has successfully been completed. Technically identical with ISO 7478:1987.