Nortel Modular Ics 6.1 Installer Guide

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Guide for a detailed description about how to use the 
feature.
• CLID display enhancements:
— display an incoming call CLID on a telephone with 
activated CLID display, where a call is currently 
active.
• overlap dialing (profile 2 only)
— For calls over PRI lines that require pauses between 
dialing sequences, this feature allows the line to send a 
dialtone to the user between dialing an access code and 
dialing the telephone...

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P0603534  02Modular ICS 6.1 Installer Guide
Welcome to ISDN
This chapter provides you with some background information 
about ISDN, including information about:
• analog vs. ISDN
• type of ISDN service
• ISDN layers
• ISDN bearer capability
• services and features for ISDN PRI and BRI
• ISDN hardware
• ISDN standards compatibility
Integrated Services Digital Network (ISDN) technology 
provides a fast, accurate, and reliable means of sending and 
receiving voice, data, images, text, and other information...

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Comparing ISDN to Analog
ISDN offers significantly higher bandwidth and speed than 
analog transmission because of its end-to-end digital 
connectivity on all transmission circuits. Being digital allows 
ISDN lines to provide better quality signaling than analog 
POTS (plain ordinary telephone) lines. Also ISDN out-of-
band data channel signaling offers faster call setup and tear 
down.
While an analog line carries only a single...

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B channels
B channels are the bearer channel. They are used to carry voice 
or data information and have speeds of 64 kbps. Since each 
ISDN line (BRI or PRI) has more than one B-channel, more 
than one transmission can occur at the same time, using a 
single ISDN line. 
D channels
The standard signaling protocol is transmitted over a dedicated 
data channel called the D-channel. The D-channel carries call 
setup and feature activation...

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Layer 1: A physical connection that supports fundamental 
signaling passed between the ISDN network (your service 
provider) and the Norstar ICS. When a DTI card configured as 
BRI or PRI is used for a network connection, the LED for the 
loop on the card is lit when the layer 1 is functioning.
Layer 2: A logical connection between the ISDN network 
(your service provider) and the Norstar ICS. Norstar has two 
of these connections for each...

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Services and features for ISDN PRI and BRI
As part of an ISDN digital network, your Modular ICS 
supports enhanced capabilities and features, including:
• faster call setup and tear down
• high quality voice transmission
• dial-up Internet and local area network (LAN) access
• video transmission
• network name display
• name and number blocking (PRI, BRI and analog)
• access to public protocols (only NI-1 for BRI)
PRI services and features...

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BRI services and features
• data transmission at speeds up to 128 kbps per loop, 
depending on the bandwidth supported by your service 
provider
• shared digital lines for voice and data ISDN terminal 
equipment
Norstar Basic Rate Interface (BRI) cards also support 
D-channel packet service between a network and terminal 
connection. This allows you to add applications such as point-
of-sale terminals without additional network connections....

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Transmission of B-channel packet data is not supported by 
Modular ICS.
Contact your ISDN service provider for more information 
about these services and features. Packages for ISDN service 
in North America are described on page 64.
The terminal equipment (TE) connected to the Norstar system 
can use some feature codes supported by the ISDN service 
provider. Refer to ISDN services and features in the Modular 
ICS 6.1 System Coordinator...

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Instead, the call will be handled in one of these ways:
• If Call Forward on Busy is programmed, the call will ring 
if a free key is available. Otherwise, it goes to the Prime 
set. DND Busy programming is ignored.
• If Call Forward All Calls is programmed, the call will go 
to the Prime set.
• If Call Forward No Answer is programmed, the call will 
continue to ring at the destination.
Note:  If a terminal rejects a call, the call goes to...