Ds1 Capabilities - AT&T MERLIN LEGEND Installation & Maintenance Manual

System Description

DS1 Capabilities

A Digital Signal One (DS1) facility is a transmission system that
transports digital signals in the DS1 format. The interface that
allows the connection of DS1 facilities to the system is the 100D
module. Through this module voice and data calls can be placed
on or received by a DS1 facility.
Twenty-four Digital Signal Zero (DS0) channels, each operating
at 64 kbps, plus framing bits, are multiplexed, forming a DS1
signal of 1.544 Mbps. Each DS0 channel within the DS1 signal
corresponds to a logical endpoint. Even though there is only one
physical jack, the 100D module supports up to 24 logical
endpoints or ports (one for each channel).
In DS1 format, calls to other digital PBXs or COs remain digital,
and signals do not need to be converted to analog for
acceptance by the connecting trunk. In addition, the 100D
module can be configured to work with T1 or Integrated Services
Digital Network Primary Rate Interface (ISDN-PRI) service.
To connect the 100D module to an outside DS1 facility, a
channel service unit (CSU) is used. The CSU regulates the
transmission into and out of the 100D module so that the module
matches the transmission of the outside facility.
Both ends of the DS1 facility must be able to "speak the same
language." To ensure this, the following options are set during
system programming to match the transmission of the outside DS1
facility:
type of service (T1 or ISDN-PRI)
framing format
line coding
line compensation
DS1 Capabilities 1-53