AT&T 7200 series Network Router User Manual


 
DATA CONNECTIVITY — AN OVERVIEW 7-11
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Note that BRI terminals follow the asynchronous user interface specification, which means that the
terminals are always in the command mode by default. This implies that whenever a call is to be placed,
the user must always dial "d<CR>" at the very least. Since the concept of hot lines means that all a user
need do is go off-hook to place a call, there is really no such thing as a true hot line for BRI terminals.
Instead, the keystroke sequence described would result in dialing the hot line number.
Data Protection
This DIMENSION, System 85, and Generic 2 feature protects data calls from intrusions by any of the system
bridge-on features (for example, Call Waiting, Override, Busy Verification).
Data Protection is provided in two forms:
Data Protection — Temporary lets user activate Data Protection on a per-call basis by entering a dial
access code. This feature is active by default on the System 85 and Generic 2 communications systems.
Data Protection — Permanent is assigned through system administration to lines and trunks used
primarily for data calls.
Data Privacy
This System 75 and Generic 1 feature protects analog data calls from being disturbed by any of the switch’s
signaling or ringing features. With Data Privacy, the switch cannot access the protected call or
superimpose any tones onto it. This feature is equivalent to the Data Protection — Temporary feature on
the DIMENSION, System 85, and Generic 2 because it is invoked on a per-call basis through a dial access
code that the user enters when placing the call.
Data Restriction
This System 75 and Generic 1 feature protects analog data calls from being distrubed by any of the switch’s
signaling or ringing features. With Data Restriction, the switch cannot access the protected call or
superimpose any tones onto it. This feature is equivalent to the Data Protection — Permanent feature on
the DIMENSION, System 85, and Generic 2 because it is assigned to a line or trunk through system
administration.
Data Only Off-Premises Extension
This feature lets on-premises users establish data calls to remote DTEs or DCEs over digital or analog
facilities. Operation of this feature is transparent to all users. Through the feature, any on-premises
terminal can access a remote data endpoint as though it were on-premises, as long as the local and remote
DCEs are compatible. Some possible configurations are shown in figure 7-5.