DIGITAL SUBSCRIBER SIGNALING SYSTEM NO. 1
Digital subscriber signaling system No. 1 (DSSl) is used for signaling between an
ISDN (integrated services digital network) subscriber and his local exchange. This chapter is a brief excursion from the description of signaling system No.7 (SS7), which has been the subject of Chapters 7 through 9, and will continue in Chapter 11, with the description of the integrated services digital network user part (ISUP). This order of presentation has been chosen because DSSl can be discussed without references to ISUP, and because it is helpful to be familiar with DSSl when exploring ISUP, which is...