Nortel Networks NN43001-106 - Manual (Page 561)

Operating parameters 561
Direct Inward Dialing (DID) trunks do not require busy tone supervision,
since the Public Exchange/Central Office seizes the system trunk by closing
the transmission loop. Far end trunk release is accomplished when the
Public Exchange/Central Office opens the circuit.
Japan trunk cards, the Extended Universal Trunk card for Japan (XUTJ) and
the Enhanced Extended Universal Trunk card for Japan (EXUTJ), do not
support this feature. The DXUT card is not supported in Japan.
The system disconnects a call when a busy tone is detected on an incoming
trunk. If the caller on the far end causes a busy tone to be generated, the call
is disconnected, regardless of whether or not disconnection was intended.
As an example, when a caller connected to a Public Exchange/Central
Office attempts to conference in a busy party, the system picks up this busy
tone and the call is disconnected.
If any other types of tones (other than busy tone) are detected with the
same cadence, frequency and level, the call is disconnected.
The Busy Tone Detection feature for Asia Pacific and CALA may not operate
on conference bridges. In the scenario of Busy Tone Detection operating
with a conference bridge, all of the trunks are incoming and an incoming
Public Exchange/Central Office trunk disconnects from a conference. In this
scenario, the disconnected trunk sends a busy tone signal to the conference
bridge, and all trunks may be disconnected simultaneously.
In the event that an incoming call is connected to an external conference
and two different Public Exchanges/Central Offices are sending busy tone
signals at the same time, a stalemate condition may exist. When this occurs,
the cadence of both busy tones may not be the same, and the resulted
combination cadences may not be detected.
The DXUT card is based on the EXUT card design and is intended to
operate in an EXUT- compatible Loss Planning environment. These EXUT
compatible Loss Planning environments include the North American Loss
Planning environment and Dynamic Loss Switching environments in certain
countries.
Busy Tone characteristics are downloaded on a card basis. The Busy
Tone Detection table assigned to the card is downloaded to the card when:
the first trunk is configured, the card is disabled and enabled, the card is
unplugged and reset, and during initialization after sysload, and when the
Intelligent Peripheral Equipment package 203 is enabled.
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
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