Signaling Protocols of Integrated Services Digital Networks

This chapter is devoted to the classical ISDN signaling protocols. The main reason for which we deal with these protocols in detail is that they are – with modifications and extensions – also used in GSM and UMTS systems. In this chapter, we discuss the access (subscriber) and the core network signaling protocol stacks of ISDN: (a)The DSS1 (Digital Subscriber Signaling System No.1): We do not deal with the physical layer, but we discuss the upper two layers: LAPD (Link Access Procedure on D channel) and DSS1 3rd layer. (b) The SS71 (Signaling System No.7): Used in core network for signaling. We introduce the structure and the functional elements of SS7, and we go through the four levels of the protocol stack.