Toshiba Strata DK14 General Description Manual page 216

Features
System Features
This is very important when using the Call-by-call feature to enable trunk groups larger than
the 23 B-channels available on one PRI line. This extends the number of call-by-call B-
channels to 47 (2 x 24 -1) and extends the number of B-channels on the second (non-signaling)
PRI line from 23 to 24. This provides better performance and cost savings in high volume
ISDN PRI applications.
Calling Number Services are provided through the D-channel function of ISDN's out-of-band
signaling format. The ISDN link sends the Caller ID for the service originating the call. This
number can be the listed directory number, DID number, or a private line number used for
billing, as well as identification to the called location. Caller ID blocking and screening are
available options. Incoming calls receive the Caller ID from the caller and is used in DK424
like ANI. DNIS information is also provided over ISDN lines.
Calling Number Services can be divided into four different types:
Number Provisioning for outgoing calls is controlled by subscription parameters with your
telco provider. The choice is for the number to be necessary or not. The number sent is
based on the call originator and the call type. The originator can be a tandem call, a station
(with or without DID), or a station with a designated number. The type of call refers to
whether it is direct or redirected (call forwarded).
For a tandem call, the Calling Party Number digits received are the digits that are sent. For
a direct station call, the default number assigned to the selected service and which is
programmed into the Strata DK as the Listed Directory Number are the number that is
sent. In this case, the system can send a fixed number (assigned in the system) or it can use
the DID programming to determine he number to be sent.
Number Screening is a feature of the public network. This is normally performed by the
network to ensure the call being placed has a valid billing number for the call. In systems
with a flexible Calling Number Provisioning, the network can perform the screening of the
call to ensure the number provided is valid for billing or reject the call, rather than
completing the call and billing it to the default Listed Directory Number.
Number Privacy enables the caller to prevent the public network from delivering the
Calling Number to the called party on a per-call basis. Service subscribers can request
from the public network that the number be presented or not as a default. Subscribers can
also select the ability to change or not change the default settings. If a public telco service
enables changes to be made, then a user can enter change a code to the setting for that call
after selecting a trunk group.
Number Delivery sends the calling number with the call setup message to indicate who is
calling, if that number is not blocked. When the Strata DK receives this number, it is
handled the same way that ANI information from T1 trunks is handled. i.e., The number
displays on the called telephone's LCD, or it can be used by TAPI interfaces, or recorded
in SMDR data records, etc.
Name Delivery is not currently supported due to the lack of a common specification for
Note
the public ISDN network.
ISDN Applications
Calling Number Services: The Signaling System 7 (SS7) communications backbone network
supports ISDN PRI trunks across various COs. ISDN depends upon SS7 out-of-band D-
channel signaling control to provide end-to-end digital connectivity. In a calling number
service application, for example, this extends calling number information across the entire
PSTN by passing this information across the various CO nodes. Calling number information is
very important in Computer Telephony Integration (CTI) applications.
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