Instruction manual

Features
At a Glance (continued)
Factory Settings (continued)
Link layer address or
TEI assigned
0 (range 0-63)
Dial Plan Routing Table
Service value
Empty
Digits per pattern Blank
Digits in CdPN
0
Digits to add
Blank
Call-by-Call Services Table
Patterns
Blank
Call type
Both (Voice and Data)
Service Blank
Digits to delete
0
Description
The Primary Rate Interface (PRI) is a standard access arrangement that can be
used to connect the system to a network providing voice and digital data
services. Releases 1.0 and 1.1 of the communications system enables PRI
connection through a 4ESS™ Generic 16. Releases 2.0 and later enable PRI
connection through a 5ESS
®
Generic 6 and a 5ESS serving the FTS2000
network. Releases 2.0 and later also include Call-by-Call Service Selection for
outgoing PRI calls and SID-ANI as a Calling Party Number.
PRI and T1
A T1 line consists of 24 channels, sometimes referred to as DS0 channels, each
with a capacity of 64 kbps. When used for PRI, a T1 channel can be
designated as either a B-channel (bearer channel) or a D-channel (data
channel). DS1 refers to the twenty-four 64-kbps channels plus framing and
signaling bits multiplexed together to form a 1.544-Mbps signal.
A B-channel is used to carry user information, such as the voice or data content
of a call, between the system and the far-end switch. Each B-channel provides
access to one or more network services. Releases 1.0 and 1.1 of the system
support access to only one network service per B-channel. Releases 2.0 and
later support Call-by-Call Service Selection, which allows multiple network
services over the same B-channels. The D-channel conveys signaling required
to set up, control, and clear calls made over all of the B-channels.
The most common configuration of a T1 line for PRI consists of 23 B-channels
and 1 D-channel, although other combinations are possible. Each PRI must
include a D-channel, but may include fewer than 23 B-channels. The remaining
channels or lines cannot be used for any other purpose.
Primary Rate Interface (PRI)
351