Specifications
Defining T1/PRI Operation
T1/PRI is the digital two-way transmission of telecommunications over a single high-speed circuit. Up to 24
separate voice or data transmissions form digital pulses that are transferred at the rate of 1.544 million bits per
second (Mbps) over the T1/PRI line. At the receiving end, the digital pulses are decoded into 24 separate
circuits.
Pulse characteristics such as repetition rate, pulse width, pulse amplitude, and average ones density ((ratio of
one (1) bits to zero (0) bits)) are as specified by digital signal level 1 (DS-1) described in American National
Standards Institute Specification, ANSI T1.403-1989.
Detailing Where You Can Install T1/PRI Boards and Its Supporting Needs
You can install up to six FXT1 boards in the FXT System. You can install these six boards in any available
universal board slot. Of course, any other line boards that you install, reduce the number of lines available
for T1/PRI service and thus reduces the number of T1/PRI boards you can install.
Whenever you install one or more boards, and the system is receiving its timing signals from an external
source (the usual case), you must install one synchronization card (DXOPT-SYN) on the auxiliary board.
This means when you connect the system to central office (CO) lines, you must include a synchronization
card, and the FXT’s system clock must be controlled by CO signaling.
Calling Party Number Type, Called Party Number Type
A programming choice that defines the number configuration that the system recognizes for both incoming
(called party) and outgoing (calling party) calls over an ISDN line. The configuration that installers choose
is based upon the type of service that they request from the service provider.
There are several choices available, but the most common choice is Subscriber (default setting) and
Dynamic (for international, national, and subscriber services). When they choose Dynamic, installers must
also set the National Prefix to 1 and the International Prefix to 011.
Network Specific Facility
There are specific types of ISDN service that can be provided by a service provider. These service types are
specified by numbers 1 through 31. The installer must contact the service provider to obtain the facility
coding value for the provided service. Installers then program this number that identifies the type of ISDN
service being supplied to the system.
General Description 6 – 59
General Description GCA40–215