Nortel Networks NN43001-106 - Manual (Page 560)

560 Busy Tone Detection for Asia Pacific and CALA
The Busy Tone Detection feature for Asia Pacific and CALA uses the
NT5D31 Digital Signaling Processor (DSP) Universal Trunk (DXUT) card.
This card is based on the Extended Universal Trunk card (EXUT) and
is configured in software as an EXUT card. However, the DXUT card
has flexible busy tone detection provided by a Digital Signal Processor
(DSP). The DXUT card also has tone detection intelligence that allows
it to accurately differentiate between different disconnect tones sent by
a Public Exchange/Central Office.
The DXUT card has programmable Busy Tone Detection characteristics
which include:
• Cadence
• Incoming or Incoming and Outgoing call direction
• Tone Frequencies
• Tone Bandwidth
• Tone Levels
Tones are detected according to the parameters configured in Overlay 97.
When a trunk card does not support the Busy Tone Detection feature, it can
still be configured in software; although, the hardware does not recognize
the new Busy Tone messages. The DXUT messages are ignored by the
old hardware.The existing hardware is still operational since the Busy
Tone feature still supports the older hardware. Old messages are sent for
backwards compatibility but are not resent to define frequency criteria.
The Automatic Balance Impedance (AUTO_BIMP) functionalities of the
DXUT card enhance the Transhybrid Loss matching capability. The
automatic balancing is performed by the Digital Signal Processor (DSP)
when checking the reflections from the transmission line. When the software
sends an AUTO_BIMP message to the DXUT card, the DSP generates a
test tone and measures the amount of signal being reflected. The DSP then
internally adjusts the balance network, in the codec, for the best Transhybrid
loss.
Operating parameters
The Busy Tone Detection feature for Asia Pacific and CALA requires
the DXUT card. The DXUT card requires busy tone detection data to be
downloaded prior to activating this feature.
The AUTO_BIMP functionalities of this feature are not supported in the
Digital Signaling Processor Universal Trunk (DXUT) card NT5D31 hardware.
Nortel Communication Server 1000
Features and Services - Book 1 of 6 (A to B)
NN43001-106 01.04 Standard
Release 5.0 27 July 2007
Copyright © 2007, Nortel Networks
.