Advanced ISDN 7-1
Chapter 7Advanced ISDN
This chapter provides information about using advanced ISDN for the Model XM128 ISDN
Digital Modem.

Call Control for DSS1

In order to initiate a Digital Subscriber Signaling #1 (DSS1) ISDN call, two information elements
are necessary:
The bearer capability element indicates what kind of bearer service is desired. It is also used
for compatibility checking in the addressed entity.
The called party number element provides necessary information for the telephone company
central office (CO) to direct the call to the destination.
The following optional information elements are also pertinent to call control:
High-layer compatibility
Low-layer compatibility
Calling party number
Called party number
Calling party subaddress
Called party subaddress