CONTENTS

        B.1     Introduction
        B.2     The SDL system diagram
        B.3     The SDL block structure diagram
        B.4     SDL specification for the nodal function
                  B.4.1     Introduction
                  B.4.2     SDL diagrams for the Nodal Function 1
                  B.4.3     Procedures in the nodal function
                  B.4.4     Data structures of AAL type 2 signalling messages and parameters
        B.5     SDL diagrams for the protocol entities
                  B.5.1     Introduction
                  B.5.2     SDL diagrams for the outgoing, incoming, and maintenance protocol procedures