Nortel BCM50 2.0, Руководство по установке

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34 Chapter 5 ISDN overview
NN40020-309 NN40020-309
Call by Call Service Selection for PRI
PRI lines can be dynamically allocated to different service types with the Call by Call feature. PRI
lines do not have to be pre-allocated to a given service type. Outgoing calls are routed through a
dedicated PRI Pool and the calls can be routed based on various schedules.
The service types that may be available, depending on your service provider are
• Public: Public service calls connect your BCM50 set with a Central Office (CO). DID and
DOD calls are supported.
• Private: Private service calls connect your BCM50 set with a Virtual Private Network. DID and
DOD calls are supported. A private dialing plan may be used.
• TIE: TIE services are private incoming and outgoing services that connect Private Branch
Exchanges (PBX) such as BCM50.
• FX (Foreign Exchange): FX service calls logically connect your BCM50 telephone to a remote
CO. It provides the equivalent of local service at the distant exchange.
• OUTWATS: OUTWATS is for outgoing calls. This allows you to originate calls to telephones
in a specific geographical area called a zone or band. Typically a flat monthly fee is charged
for this service.
• Inwats: Inwats is a type of long distance service which allows you to receive calls originating
within specified areas without a charge to the caller. A toll-free number is assigned to allow for
reversed billing.
Consult your customer service representative to determine whether or not this feature is
compatible with your provider.
Emergency 911 dialing
The ISDN PRI feature is capable of transmitting the telephone number and internal extension
number of a calling station dialing 911 to the Public Switched Telephone Network (PSTN). State
and local requirements for support of Emergency 911 dialing service by Customer Premises
Equipment vary. Consult your local telecommunications service provider regarding compliance
with applicable laws and regulations. For most installations the following configuration rules
should be followed, unless local regulations require a modification.
• All PSTN connections must be over PRI.
• In order for all sets to be reached from a Public Safety Answering Position (PSAP), the system
must be configured for DID access to all sets. In order to reduce confusion, the dial digits for
each set should be configured to correspond to the set extension number.
Note: Call by Call Service Selection for PRI is only available in North
America.
Note: Emergency 911 dialing is only available in North America.