3Com 3C10111C - NBX 100 - Modular Exp Base, Руководство по установке

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146 C
HAPTER
8: T1 D
IGITAL
L
INE
C
ARD
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The NBX system provides E911 (emergency) connectivity if the T1
Digital Line Card is configured for ISDN PRI (Primary Rate Interface)
signaling. The system provides the calling number (ANI) so that the
emergency services personnel can determine the location of the caller
from the E911 database. You must update the CO (PSAP) databases.
Adding a T1 Digital
Line Card
Adding a T1 Digital Line Card to a system requires:
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Preparing the NBX System for a T1 Card
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Ordering DID (Direct Inward Dialing) Services for T1
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Enabling Auto Discover for Digital Line Cards
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Inserting the T1 Digital Line Card
Preparing the NBX
System for a T1 Card
Before you insert the T1 Digital Line Card into the chassis, order a T1 line
from your telephone carrier and have them install the line. In some cases,
the telephone company offers T1 services only with specific, pre-defined
parameters. However, some telephone companies offer a number of
configuration choices with their T1 services.
Ordering DID (Direct
Inward Dialing)
Services for T1
When you order a T1 line with DID capability (Direct Inward Dial), the
local telephone carrier assigns a block of telephone numbers to you.
Usually, you can request a specific range of numbers, but sometimes the
carrier assigns numbers other than the ones you request.
You may be able to request that the local telephone carrier pass you a
specific number of digits for each incoming telephone call. Sometimes
the carrier does not offer any choice. In either situation, you need to
know how many digits the carrier passes.
Example: Carriers commonly pass either the last three digits or last four
digits of the number for each incoming call. Sometimes the last digits of
the telephone numbers the carrier assigns to you do not match the
telephone extension numbers you want to use for internal calls. You can
create entries in your Dial Plan configuration file to translate the incoming
numbers into the corresponding extension numbers.
Example: You want to use internal extensions from 4000 through 4999,
but the local telephone carrier assigns you numbers from 617-555-3500
through 617-555-4499. You can create translator entries in the Dial Plan
configuration file to translate an incoming digit sequence such as 3795