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Advanced ISDN Call Control 79
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Advanced ISDN Call
Control
Call Control for DSS1
In order to initiate a DSS1 ISDN call, two information elements are
necessary:
necessary:
•
Bearer Capability - indicates what kind of bearer service is
desired. It is also used for compatibility checking in the addressed
entity.
desired. It is also used for compatibility checking in the addressed
entity.
•
Called Party Number - provides necessary information for the
telephone company Central Office (CO) to direct the call to the
destination.
telephone company Central Office (CO) to direct the call to the
destination.
Other optional information elements which are pertinent to call
control include:
control include:
•
High-Layer-Compatibility.
•
Low-Layer-Compatibility.
•
Calling-Party-Number.
•
Called-Party-Number.
•
Calling-Party-Subaddress.
•
Called-Party-Subaddress.
Control of Outgoing Service Indicator
The High-Layer-Compatibility and Low-Layer-Compatibility
information provides a means for compatibility checking by the called
party. They are transferred transparently by the ISDN network
between the call originating entity (e.g. the calling user) and the
addressed entity.
information provides a means for compatibility checking by the called
party. They are transferred transparently by the ISDN network
between the call originating entity (e.g. the calling user) and the
addressed entity.