Terminating Impedance; Digital Trunk And Primary Rate Interface; Basic Rate Interface Line And Trunk; Meridian Modular Telephones - Nortel Meridian 1 Succession 1000 Manual

Page 30 of 236 Transmission level adjustment

Terminating Impedance

Digital Trunk and Primary Rate Interface

Basic Rate Interface Line and Trunk

Meridian Modular Telephones

553-3001-182 Standard 1.00
network that ensures proper impedance matches when connecting to a
four-wire interface. The 3COM impedance network ensures stability and
eliminates echo caused by impedance mismatches.
For IPE cards, this option is controlled by software configuration.
Some analog trunk and the Extended Off-premises Station (XOPS) cards
have Terminating Impedance options that ensure proper impedance matches
when connecting to an external interface. The Terminating Impedance
options are 600 ¾ and 900 ¾.
For IPE cards, this option is controlled by software configuration.
Digital Trunk Interface (DTI) and Primary Rate Interface (PRI) trunks adjust
transmission level by applying software-defined pad values based on the port
type involved in the connection. The pad value can be either negative, e.g.,
-3.0 dB (GAIN) or positive, e.g., +3.0 dB (LOSS). The gain and loss sign
conventions appear to be contrary to intuition; however, from the point of
view of looking at signals traversing cables, loss is the quantity of interest and
is positive, therefore an increase in signal strength is a negative loss, referred
to as a gain.
Basic Rate Interface Lines and Trunks adjust transmission level in the same
manner as DTI/PRI trunks do. That is, they apply pad values based on the port
type involved in the connection. Basic Rate Interface Lines (BRIL) apply
fixed pad values, while Basic Rate Interface Trunks (BRIT) apply software
defined pad values.
Meridian Modular Telephones download software-defined Objective
Loudness Rating (OLR) settings that set the level at the Central Office or
October 2003